#ifndef SQL_ITEM_INCLUDED #define SQL_ITEM_INCLUDED /* Copyright (c) 2000, 2011, Oracle and/or its affiliates. Copyright (c) 2009-2011 Monty Program Ab This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifdef USE_PRAGMA_INTERFACE #pragma interface /* gcc class implementation */ #endif #include "sql_priv.h" /* STRING_BUFFER_USUAL_SIZE */ #include "unireg.h" #include "sql_const.h" /* RAND_TABLE_BIT, MAX_FIELD_NAME */ #include "unireg.h" // REQUIRED: for other includes #include "thr_malloc.h" /* sql_calloc */ #include "field.h" /* Derivation */ C_MODE_START #include C_MODE_END static inline bool trace_unsupported_func(const char *where, const char *processor_name) { char buff[64]; sprintf(buff, "%s::%s", where, processor_name); DBUG_ENTER(buff); sprintf(buff, "%s returns TRUE: unsupported function", processor_name); DBUG_PRINT("info", ("%s", buff)); DBUG_RETURN(TRUE); } static inline bool trace_unsupported_by_check_vcol_func_processor(const char *where) { return trace_unsupported_func(where, "check_vcol_func_processor"); } class Protocol; struct TABLE_LIST; void item_init(void); /* Init item functions */ class Item_field; class user_var_entry; static inline uint32 char_to_byte_length_safe(uint32 char_length_arg, uint32 mbmaxlen_arg) { ulonglong tmp= ((ulonglong) char_length_arg) * mbmaxlen_arg; return (tmp > UINT_MAX32) ? (uint32) UINT_MAX32 : (uint32) tmp; } /* "Declared Type Collation" A combination of collation and its derivation. Flags for collation aggregation modes: MY_COLL_ALLOW_SUPERSET_CONV - allow conversion to a superset MY_COLL_ALLOW_COERCIBLE_CONV - allow conversion of a coercible value (i.e. constant). MY_COLL_ALLOW_CONV - allow any kind of conversion (combination of the above two) MY_COLL_ALLOW_NUMERIC_CONV - if all items were numbers, convert to @@character_set_connection MY_COLL_DISALLOW_NONE - don't allow return DERIVATION_NONE (e.g. when aggregating for comparison) MY_COLL_CMP_CONV - combination of MY_COLL_ALLOW_CONV and MY_COLL_DISALLOW_NONE */ #define MY_COLL_ALLOW_SUPERSET_CONV 1 #define MY_COLL_ALLOW_COERCIBLE_CONV 2 #define MY_COLL_DISALLOW_NONE 4 #define MY_COLL_ALLOW_NUMERIC_CONV 8 #define MY_COLL_ALLOW_CONV (MY_COLL_ALLOW_SUPERSET_CONV | MY_COLL_ALLOW_COERCIBLE_CONV) #define MY_COLL_CMP_CONV (MY_COLL_ALLOW_CONV | MY_COLL_DISALLOW_NONE) class DTCollation { public: CHARSET_INFO *collation; enum Derivation derivation; uint repertoire; void set_repertoire_from_charset(CHARSET_INFO *cs) { repertoire= cs->state & MY_CS_PUREASCII ? MY_REPERTOIRE_ASCII : MY_REPERTOIRE_UNICODE30; } DTCollation() { collation= &my_charset_bin; derivation= DERIVATION_NONE; repertoire= MY_REPERTOIRE_UNICODE30; } DTCollation(CHARSET_INFO *collation_arg, Derivation derivation_arg) { collation= collation_arg; derivation= derivation_arg; set_repertoire_from_charset(collation_arg); } void set(DTCollation &dt) { collation= dt.collation; derivation= dt.derivation; repertoire= dt.repertoire; } void set(CHARSET_INFO *collation_arg, Derivation derivation_arg) { collation= collation_arg; derivation= derivation_arg; set_repertoire_from_charset(collation_arg); } void set(CHARSET_INFO *collation_arg, Derivation derivation_arg, uint repertoire_arg) { collation= collation_arg; derivation= derivation_arg; repertoire= repertoire_arg; } void set_numeric() { collation= &my_charset_numeric; derivation= DERIVATION_NUMERIC; repertoire= MY_REPERTOIRE_NUMERIC; } void set(CHARSET_INFO *collation_arg) { collation= collation_arg; set_repertoire_from_charset(collation_arg); } void set(Derivation derivation_arg) { derivation= derivation_arg; } bool aggregate(DTCollation &dt, uint flags= 0); bool set(DTCollation &dt1, DTCollation &dt2, uint flags= 0) { set(dt1); return aggregate(dt2, flags); } const char *derivation_name() const { switch(derivation) { case DERIVATION_NUMERIC: return "NUMERIC"; case DERIVATION_IGNORABLE: return "IGNORABLE"; case DERIVATION_COERCIBLE: return "COERCIBLE"; case DERIVATION_IMPLICIT: return "IMPLICIT"; case DERIVATION_SYSCONST: return "SYSCONST"; case DERIVATION_EXPLICIT: return "EXPLICIT"; case DERIVATION_NONE: return "NONE"; default: return "UNKNOWN"; } } }; /*************************************************************************/ /* A framework to easily handle different return types for hybrid items (hybrid item is an item whose operand can be of any type, e.g. integer, real, decimal). */ struct Hybrid_type_traits; struct Hybrid_type { longlong integer; double real; /* Use two decimal buffers interchangeably to speed up += operation which has no native support in decimal library. Hybrid_type+= arg is implemented as dec_buf[1]= dec_buf[0] + arg. The third decimal is used as a handy temporary storage. */ my_decimal dec_buf[3]; int used_dec_buf_no; /* Traits moved to a separate class to a) be able to easily change object traits in runtime b) they work as a differentiator for the union above */ const Hybrid_type_traits *traits; Hybrid_type() {} /* XXX: add traits->copy() when needed */ Hybrid_type(const Hybrid_type &rhs) :traits(rhs.traits) {} }; /* Hybryd_type_traits interface + default implementation for REAL_RESULT */ struct Hybrid_type_traits { virtual Item_result type() const { return REAL_RESULT; } virtual void fix_length_and_dec(Item *item, Item *arg) const; /* Hybrid_type operations. */ virtual void set_zero(Hybrid_type *val) const { val->real= 0.0; } virtual void add(Hybrid_type *val, Field *f) const { val->real+= f->val_real(); } virtual void div(Hybrid_type *val, ulonglong u) const { val->real/= ulonglong2double(u); } virtual longlong val_int(Hybrid_type *val, bool unsigned_flag) const { return (longlong) rint(val->real); } virtual double val_real(Hybrid_type *val) const { return val->real; } virtual my_decimal *val_decimal(Hybrid_type *val, my_decimal *buf) const; virtual String *val_str(Hybrid_type *val, String *buf, uint8 decimals) const; static const Hybrid_type_traits *instance(); Hybrid_type_traits() {} virtual ~Hybrid_type_traits() {} }; struct Hybrid_type_traits_decimal: public Hybrid_type_traits { virtual Item_result type() const { return DECIMAL_RESULT; } virtual void fix_length_and_dec(Item *arg, Item *item) const; /* Hybrid_type operations. */ virtual void set_zero(Hybrid_type *val) const; virtual void add(Hybrid_type *val, Field *f) const; virtual void div(Hybrid_type *val, ulonglong u) const; virtual longlong val_int(Hybrid_type *val, bool unsigned_flag) const; virtual double val_real(Hybrid_type *val) const; virtual my_decimal *val_decimal(Hybrid_type *val, my_decimal *buf) const { return &val->dec_buf[val->used_dec_buf_no]; } virtual String *val_str(Hybrid_type *val, String *buf, uint8 decimals) const; static const Hybrid_type_traits_decimal *instance(); Hybrid_type_traits_decimal() {}; }; struct Hybrid_type_traits_integer: public Hybrid_type_traits { virtual Item_result type() const { return INT_RESULT; } virtual void fix_length_and_dec(Item *arg, Item *item) const; /* Hybrid_type operations. */ virtual void set_zero(Hybrid_type *val) const { val->integer= 0; } virtual void add(Hybrid_type *val, Field *f) const { val->integer+= f->val_int(); } virtual void div(Hybrid_type *val, ulonglong u) const { val->integer/= (longlong) u; } virtual longlong val_int(Hybrid_type *val, bool unsigned_flag) const { return val->integer; } virtual double val_real(Hybrid_type *val) const { return (double) val->integer; } virtual my_decimal *val_decimal(Hybrid_type *val, my_decimal *buf) const { int2my_decimal(E_DEC_FATAL_ERROR, val->integer, 0, &val->dec_buf[2]); return &val->dec_buf[2]; } virtual String *val_str(Hybrid_type *val, String *buf, uint8 decimals) const { buf->set(val->integer, &my_charset_bin); return buf;} static const Hybrid_type_traits_integer *instance(); Hybrid_type_traits_integer() {}; }; void dummy_error_processor(THD *thd, void *data); void view_error_processor(THD *thd, void *data); /* Instances of Name_resolution_context store the information necesary for name resolution of Items and other context analysis of a query made in fix_fields(). This structure is a part of SELECT_LEX, a pointer to this structure is assigned when an item is created (which happens mostly during parsing (sql_yacc.yy)), but the structure itself will be initialized after parsing is complete TODO: move subquery of INSERT ... SELECT and CREATE ... SELECT to separate SELECT_LEX which allow to remove tricks of changing this structure before and after INSERT/CREATE and its SELECT to make correct field name resolution. */ struct Name_resolution_context: Sql_alloc { /* The name resolution context to search in when an Item cannot be resolved in this context (the context of an outer select) */ Name_resolution_context *outer_context; /* List of tables used to resolve the items of this context. Usually these are tables from the FROM clause of SELECT statement. The exceptions are INSERT ... SELECT and CREATE ... SELECT statements, where SELECT subquery is not moved to a separate SELECT_LEX. For these types of statements we have to change this member dynamically to ensure correct name resolution of different parts of the statement. */ TABLE_LIST *table_list; /* In most cases the two table references below replace 'table_list' above for the purpose of name resolution. The first and last name resolution table references allow us to search only in a sub-tree of the nested join tree in a FROM clause. This is needed for NATURAL JOIN, JOIN ... USING and JOIN ... ON. */ TABLE_LIST *first_name_resolution_table; /* Last table to search in the list of leaf table references that begins with first_name_resolution_table. */ TABLE_LIST *last_name_resolution_table; /* SELECT_LEX item belong to, in case of merged VIEW it can differ from SELECT_LEX where item was created, so we can't use table_list/field_list from there */ st_select_lex *select_lex; /* Processor of errors caused during Item name resolving, now used only to hide underlying tables in errors about views (i.e. it substitute some errors for views) */ void (*error_processor)(THD *, void *); void *error_processor_data; /* When TRUE items are resolved in this context both against the SELECT list and this->table_list. If FALSE, items are resolved only against this->table_list. */ bool resolve_in_select_list; /* Security context of this name resolution context. It's used for views and is non-zero only if the view is defined with SQL SECURITY DEFINER. */ Security_context *security_ctx; Name_resolution_context() :outer_context(0), table_list(0), select_lex(0), error_processor_data(0), security_ctx(0) {} void init() { resolve_in_select_list= FALSE; error_processor= &dummy_error_processor; first_name_resolution_table= NULL; last_name_resolution_table= NULL; } void resolve_in_table_list_only(TABLE_LIST *tables) { table_list= first_name_resolution_table= tables; resolve_in_select_list= FALSE; } void process_error(THD *thd) { (*error_processor)(thd, error_processor_data); } }; /* Store and restore the current state of a name resolution context. */ class Name_resolution_context_state { private: TABLE_LIST *save_table_list; TABLE_LIST *save_first_name_resolution_table; TABLE_LIST *save_next_name_resolution_table; bool save_resolve_in_select_list; TABLE_LIST *save_next_local; public: Name_resolution_context_state() {} /* Remove gcc warning */ public: /* Save the state of a name resolution context. */ void save_state(Name_resolution_context *context, TABLE_LIST *table_list) { save_table_list= context->table_list; save_first_name_resolution_table= context->first_name_resolution_table; save_resolve_in_select_list= context->resolve_in_select_list; save_next_local= table_list->next_local; save_next_name_resolution_table= table_list->next_name_resolution_table; } /* Restore a name resolution context from saved state. */ void restore_state(Name_resolution_context *context, TABLE_LIST *table_list) { table_list->next_local= save_next_local; table_list->next_name_resolution_table= save_next_name_resolution_table; context->table_list= save_table_list; context->first_name_resolution_table= save_first_name_resolution_table; context->resolve_in_select_list= save_resolve_in_select_list; } TABLE_LIST *get_first_name_resolution_table() { return save_first_name_resolution_table; } }; /* This enum is used to report information about monotonicity of function represented by Item* tree. Monotonicity is defined only for Item* trees that represent table partitioning expressions (i.e. have no subselects/user vars/PS parameters etc etc). An Item* tree is assumed to have the same monotonicity properties as its correspoinding function F: [signed] longlong F(field1, field2, ...) { put values of field_i into table record buffer; return item->val_int(); } NOTE At the moment function monotonicity is not well defined (and so may be incorrect) for Item trees with parameters/return types that are different from INT_RESULT, may be NULL, or are unsigned. It will be possible to address this issue once the related partitioning bugs (BUG#16002, BUG#15447, BUG#13436) are fixed. The NOT_NULL enums are used in TO_DAYS, since TO_DAYS('2001-00-00') returns NULL which puts those rows into the NULL partition, but '2000-12-31' < '2001-00-00' < '2001-01-01'. So special handling is needed for this (see Bug#20577). */ typedef enum monotonicity_info { NON_MONOTONIC, /* none of the below holds */ MONOTONIC_INCREASING, /* F() is unary and (x < y) => (F(x) <= F(y)) */ MONOTONIC_INCREASING_NOT_NULL, /* But only for valid/real x and y */ MONOTONIC_STRICT_INCREASING,/* F() is unary and (x < y) => (F(x) < F(y)) */ MONOTONIC_STRICT_INCREASING_NOT_NULL /* But only for valid/real x and y */ } enum_monotonicity_info; /*************************************************************************/ class sp_rcontext; class Settable_routine_parameter { public: /* Set required privileges for accessing the parameter. SYNOPSIS set_required_privilege() rw if 'rw' is true then we are going to read and set the parameter, so SELECT and UPDATE privileges might be required, otherwise we only reading it and SELECT privilege might be required. */ Settable_routine_parameter() {} virtual ~Settable_routine_parameter() {} virtual void set_required_privilege(bool rw) {}; /* Set parameter value. SYNOPSIS set_value() thd thread handle ctx context to which parameter belongs (if it is local variable). it item which represents new value RETURN FALSE if parameter value has been set, TRUE if error has occured. */ virtual bool set_value(THD *thd, sp_rcontext *ctx, Item **it)= 0; virtual void set_out_param_info(Send_field *info) {} virtual const Send_field *get_out_param_info() const { return NULL; } }; struct st_dyncall_create_def { Item *num, *value; CHARSET_INFO *cs; uint len, frac; DYNAMIC_COLUMN_TYPE type; }; typedef struct st_dyncall_create_def DYNCALL_CREATE_DEF; typedef bool (Item::*Item_processor) (uchar *arg); /* Analyzer function SYNOPSIS argp in/out IN: Analysis parameter OUT: Parameter to be passed to the transformer RETURN TRUE Invoke the transformer FALSE Don't do it */ typedef bool (Item::*Item_analyzer) (uchar **argp); typedef Item* (Item::*Item_transformer) (uchar *arg); typedef void (*Cond_traverser) (const Item *item, void *arg); class Item_equal; class COND_EQUAL; class st_select_lex_unit; class Item { Item(const Item &); /* Prevent use of these */ void operator=(Item &); /** The index in the JOIN::join_tab array of the JOIN_TAB this Item is attached to. Items are attached (or 'pushed') to JOIN_TABs during optimization by the make_cond_for_table procedure. During query execution, this item is evaluated when the join loop reaches the corresponding JOIN_TAB. If the value of join_tab_idx >= MAX_TABLES, this means that there is no corresponding JOIN_TAB. */ uint join_tab_idx; public: static void *operator new(size_t size) throw () { return sql_alloc(size); } static void *operator new(size_t size, MEM_ROOT *mem_root) throw () { return alloc_root(mem_root, size); } static void operator delete(void *ptr,size_t size) { TRASH(ptr, size); } static void operator delete(void *ptr, MEM_ROOT *mem_root) {} enum Type {FIELD_ITEM= 0, FUNC_ITEM, SUM_FUNC_ITEM, STRING_ITEM, INT_ITEM, REAL_ITEM, NULL_ITEM, VARBIN_ITEM, COPY_STR_ITEM, FIELD_AVG_ITEM, DEFAULT_VALUE_ITEM, PROC_ITEM,COND_ITEM, REF_ITEM, FIELD_STD_ITEM, FIELD_VARIANCE_ITEM, INSERT_VALUE_ITEM, SUBSELECT_ITEM, ROW_ITEM, CACHE_ITEM, TYPE_HOLDER, PARAM_ITEM, TRIGGER_FIELD_ITEM, DECIMAL_ITEM, XPATH_NODESET, XPATH_NODESET_CMP, VIEW_FIXER_ITEM, EXPR_CACHE_ITEM}; enum cond_result { COND_UNDEF,COND_OK,COND_TRUE,COND_FALSE }; enum traverse_order { POSTFIX, PREFIX }; /* Cache of the result of is_expensive(). */ int8 is_expensive_cache; /* Reuse size, only used by SP local variable assignment, otherwize 0 */ uint rsize; /* str_values's main purpose is to be used to cache the value in save_in_field */ String str_value; char * name; /* Name from select */ /* Original item name (if it was renamed)*/ char * orig_name; /** Intrusive list pointer for free list. If not null, points to the next Item on some Query_arena's free list. For instance, stored procedures have their own Query_arena's. @see Query_arena::free_list */ Item *next; uint32 max_length; /* Maximum length, in bytes */ /* TODO: convert name and name_length fields into LEX_STRING to keep them in sync (see bug #11829681/60295 etc). Then also remove some strlen(name) calls. */ uint name_length; /* Length of name */ int8 marker; uint8 decimals; bool maybe_null; /* If item may be null */ bool in_rollup; /* If used in GROUP BY list of a query with ROLLUP */ bool null_value; /* if item is null */ bool unsigned_flag; bool with_sum_func; /* True if item contains a sum func */ /** True if any item except Item_sum_func contains a field. Set during parsing. */ bool with_field; bool fixed; /* If item fixed with fix_fields */ bool is_autogenerated_name; /* indicate was name of this Item autogenerated or set by user */ bool with_subselect; /* If this item is a subselect or some of its arguments is or contains a subselect */ DTCollation collation; Item_result cmp_context; /* Comparison context */ // alloc & destruct is done as start of select using sql_alloc Item(); /* Constructor used by Item_field, Item_ref & aggregate (sum) functions. Used for duplicating lists in processing queries with temporary tables Also it used for Item_cond_and/Item_cond_or for creating top AND/OR structure of WHERE clause to protect it of optimisation changes in prepared statements */ Item(THD *thd, Item *item); virtual ~Item() { #ifdef EXTRA_DEBUG name=0; #endif } /*lint -e1509 */ void set_name(const char *str, uint length, CHARSET_INFO *cs); void rename(char *new_name); void init_make_field(Send_field *tmp_field,enum enum_field_types type); virtual void cleanup(); virtual void make_field(Send_field *field); Field *make_string_field(TABLE *table); virtual bool fix_fields(THD *, Item **); /* Fix after some tables has been pulled out. Basically re-calculate all attributes that are dependent on the tables. */ virtual void fix_after_pullout(st_select_lex *new_parent, Item **ref) {}; /* This method should be used in case where we are sure that we do not need complete fix_fields() procedure. Usually this method is used by the optimizer when it has to create a new item out of other already fixed items. For example, if the optimizer has to create a new Item_func for an inferred equality whose left and right parts are already fixed items. In some cases the optimizer cannot use directly fixed items as the arguments of the created functional item, but rather uses intermediate type conversion items. Then the method is supposed to be applied recursively. */ virtual inline void quick_fix_field() { fixed= 1; } /* Function returns 1 on overflow and -1 on fatal errors */ int save_in_field_no_warnings(Field *field, bool no_conversions); virtual int save_in_field(Field *field, bool no_conversions); virtual void save_org_in_field(Field *field) { (void) save_in_field(field, 1); } virtual int save_safe_in_field(Field *field) { return save_in_field(field, 1); } virtual bool send(Protocol *protocol, String *str); virtual bool eq(const Item *, bool binary_cmp) const; /* result_type() of an item specifies how the value should be returned */ virtual Item_result result_type() const { return REAL_RESULT; } /* ... while cmp_type() specifies how it should be compared */ virtual Item_result cmp_type() const; virtual Item_result cast_to_int_type() const { return cmp_type(); } virtual enum_field_types string_field_type() const; virtual enum_field_types field_type() const; virtual enum Type type() const =0; /* real_type() is the type of base item. This is same as type() for most items, except Item_ref() and Item_cache_wrapper() where it shows the type for the underlaying item. */ virtual enum Type real_type() const { return type(); } /* Return information about function monotonicity. See comment for enum_monotonicity_info for details. This function can only be called after fix_fields() call. */ virtual enum_monotonicity_info get_monotonicity_info() const { return NON_MONOTONIC; } /* Convert "func_arg $CMP$ const" half-interval into "FUNC(func_arg) $CMP2$ const2" SYNOPSIS val_int_endpoint() left_endp FALSE <=> The interval is "x < const" or "x <= const" TRUE <=> The interval is "x > const" or "x >= const" incl_endp IN FALSE <=> the comparison is '<' or '>' TRUE <=> the comparison is '<=' or '>=' OUT The same but for the "F(x) $CMP$ F(const)" comparison DESCRIPTION This function is defined only for unary monotonic functions. The caller supplies the source half-interval x $CMP$ const The value of const is supplied implicitly as the value this item's argument, the form of $CMP$ comparison is specified through the function's arguments. The calle returns the result interval F(x) $CMP2$ F(const) passing back F(const) as the return value, and the form of $CMP2$ through the out parameter. NULL values are assumed to be comparable and be less than any non-NULL values. RETURN The output range bound, which equal to the value of val_int() - If the value of the function is NULL then the bound is the smallest possible value of LONGLONG_MIN */ virtual longlong val_int_endpoint(bool left_endp, bool *incl_endp) { DBUG_ASSERT(0); return 0; } /* valXXX methods must return NULL or 0 or 0.0 if null_value is set. */ /* Return double precision floating point representation of item. SYNOPSIS val_real() RETURN In case of NULL value return 0.0 and set null_value flag to TRUE. If value is not null null_value flag will be reset to FALSE. */ virtual double val_real()=0; /* Return integer representation of item. SYNOPSIS val_int() RETURN In case of NULL value return 0 and set null_value flag to TRUE. If value is not null null_value flag will be reset to FALSE. */ virtual longlong val_int()=0; /* This is just a shortcut to avoid the cast. You should still use unsigned_flag to check the sign of the item. */ inline ulonglong val_uint() { return (ulonglong) val_int(); } /* Return string representation of this item object. SYNOPSIS val_str() str an allocated buffer this or any nested Item object can use to store return value of this method. NOTE Buffer passed via argument should only be used if the item itself doesn't have an own String buffer. In case when the item maintains it's own string buffer, it's preferable to return it instead to minimize number of mallocs/memcpys. The caller of this method can modify returned string, but only in case when it was allocated on heap, (is_alloced() is true). This allows the caller to efficiently use a buffer allocated by a child without having to allocate a buffer of it's own. The buffer, given to val_str() as argument, belongs to the caller and is later used by the caller at it's own choosing. A few implications from the above: - unless you return a string object which only points to your buffer but doesn't manages it you should be ready that it will be modified. - even for not allocated strings (is_alloced() == false) the caller can change charset (see Item_func_{typecast/binary}. XXX: is this a bug? - still you should try to minimize data copying and return internal object whenever possible. RETURN In case of NULL value return 0 (NULL pointer) and set null_value flag to TRUE. If value is not null null_value flag will be reset to FALSE. */ virtual String *val_str(String *str)=0; /* Returns string representation of this item in ASCII format. SYNOPSIS val_str_ascii() str - similar to val_str(); NOTE This method is introduced for performance optimization purposes. 1. val_str() result of some Items in string context depends on @@character_set_results. @@character_set_results can be set to a "real multibyte" character set like UCS2, UTF16, UTF32. (We'll use only UTF32 in the examples below for convenience.) So the default string result of such functions in these circumstances is real multi-byte character set, like UTF32. For example, all numbers in string context return result in @@character_set_results: SELECT CONCAT(20010101); -> UTF32 We do sprintf() first (to get ASCII representation) and then convert to UTF32; So these kind "data sources" can use ASCII representation internally, but return multi-byte data only because @@character_set_results wants so. Therefore, conversion from ASCII to UTF32 is applied internally. 2. Some other functions need in fact ASCII input. For example, inet_aton(), GeometryFromText(), Convert_TZ(), GET_FORMAT(). Similar, fields of certain type, like DATE, TIME, when you insert string data into them, expect in fact ASCII input. If they get non-ASCII input, for example UTF32, they convert input from UTF32 to ASCII, and then use ASCII representation to do further processing. 3. Now imagine we pass result of a data source of the first type to a data destination of the second type. What happens: a. data source converts data from ASCII to UTF32, because @@character_set_results wants so and passes the result to data destination. b. data destination gets UTF32 string. c. data destination converts UTF32 string to ASCII, because it needs ASCII representation to be able to handle data correctly. As a result we get two steps of unnecessary conversion: From ASCII to UTF32, then from UTF32 to ASCII. A better way to handle these situations is to pass ASCII representation directly from the source to the destination. This is why val_str_ascii() introduced. RETURN Similar to val_str() */ virtual String *val_str_ascii(String *str); /* Return decimal representation of item with fixed point. SYNOPSIS val_decimal() decimal_buffer buffer which can be used by Item for returning value (but can be not) NOTE Returned value should not be changed if it is not the same which was passed via argument. RETURN Return pointer on my_decimal (it can be other then passed via argument) if value is not NULL (null_value flag will be reset to FALSE). In case of NULL value it return 0 pointer and set null_value flag to TRUE. */ virtual my_decimal *val_decimal(my_decimal *decimal_buffer)= 0; /* Return boolean value of item. RETURN FALSE value is false or NULL TRUE value is true (not equal to 0) */ virtual bool val_bool(); virtual String *val_nodeset(String*) { return 0; } /* save_val() is method of val_* family which stores value in the given field. */ virtual void save_val(Field *to) { save_org_in_field(to); } /* save_result() is method of val*result() family which stores value in the given field. */ virtual void save_result(Field *to) { save_val(to); } /* Helper functions, see item_sum.cc */ String *val_string_from_real(String *str); String *val_string_from_int(String *str); String *val_string_from_decimal(String *str); String *val_string_from_date(String *str); my_decimal *val_decimal_from_real(my_decimal *decimal_value); my_decimal *val_decimal_from_int(my_decimal *decimal_value); my_decimal *val_decimal_from_string(my_decimal *decimal_value); my_decimal *val_decimal_from_date(my_decimal *decimal_value); my_decimal *val_decimal_from_time(my_decimal *decimal_value); longlong val_int_from_decimal(); double val_real_from_decimal(); int save_time_in_field(Field *field); int save_date_in_field(Field *field); int save_str_value_in_field(Field *field, String *result); virtual Field *get_tmp_table_field() { return 0; } /* This is also used to create fields in CREATE ... SELECT: */ virtual Field *tmp_table_field(TABLE *t_arg) { return 0; } virtual const char *full_name() const { return name ? name : "???"; } const char *field_name_or_null() { return real_item()->type() == Item::FIELD_ITEM ? name : NULL; } /* *result* family of methods is analog of *val* family (see above) but return value of result_field of item if it is present. If Item have not result field, it return val(). This methods set null_value flag in same way as *val* methods do it. */ virtual double val_result() { return val_real(); } virtual longlong val_int_result() { return val_int(); } virtual String *str_result(String* tmp) { return val_str(tmp); } virtual my_decimal *val_decimal_result(my_decimal *val) { return val_decimal(val); } virtual bool val_bool_result() { return val_bool(); } virtual bool is_null_result() { return is_null(); } /* Returns 1 if result type and collation for val_str() can change between calls */ virtual bool dynamic_result() { return 0; } /* Bitmap of tables used by item (note: if you need to check dependencies on individual columns, check out class Field_enumerator) */ virtual table_map used_tables() const { return (table_map) 0L; } virtual table_map all_used_tables() const { return used_tables(); } /* Return table map of tables that can't be NULL tables (tables that are used in a context where if they would contain a NULL row generated by a LEFT or RIGHT join, the item would not be true). This expression is used on WHERE item to determinate if a LEFT JOIN can be converted to a normal join. Generally this function should return used_tables() if the function would return null if any of the arguments are null As this is only used in the beginning of optimization, the value don't have to be updated in update_used_tables() */ virtual table_map not_null_tables() const { return used_tables(); } /* Returns true if this is a simple constant item like an integer, not a constant expression. Used in the optimizer to propagate basic constants. */ virtual bool basic_const_item() const { return 0; } /* cloning of constant items (0 if it is not const) */ virtual Item *clone_item() { return 0; } virtual cond_result eq_cmp_result() const { return COND_OK; } inline uint float_length(uint decimals_par) const { return decimals != NOT_FIXED_DEC ? (DBL_DIG+2+decimals_par) : DBL_DIG+8;} virtual uint decimal_precision() const; inline int decimal_int_part() const { return my_decimal_int_part(decimal_precision(), decimals); } /* Returns true if this is constant (during query execution, i.e. its value will not change until next fix_fields) and its value is known. */ virtual bool const_item() const { return used_tables() == 0; } /* Returns true if this is constant but its value may be not known yet. (Can be used for parameters of prep. stmts or of stored procedures.) */ virtual bool const_during_execution() const { return (used_tables() & ~PARAM_TABLE_BIT) == 0; } /** This method is used for to: - to generate a view definition query (SELECT-statement); - to generate a SQL-query for EXPLAIN EXTENDED; - to generate a SQL-query to be shown in INFORMATION_SCHEMA; - debug. For more information about view definition query, INFORMATION_SCHEMA query and why they should be generated from the Item-tree, @see mysql_register_view(). */ virtual inline void print(String *str, enum_query_type query_type) { str->append(full_name()); } void print_item_w_name(String *, enum_query_type query_type); void print_value(String *); virtual void update_used_tables() {} virtual void split_sum_func(THD *thd, Item **ref_pointer_array, List &fields) {} /* Called for items that really have to be split */ void split_sum_func2(THD *thd, Item **ref_pointer_array, List &fields, Item **ref, bool skip_registered); virtual bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate); bool get_time(MYSQL_TIME *ltime) { return get_date(ltime, TIME_TIME_ONLY | TIME_FUZZY_DATE); } bool get_seconds(ulonglong *sec, ulong *sec_part); virtual bool get_date_result(MYSQL_TIME *ltime, ulonglong fuzzydate) { return get_date(ltime,fuzzydate); } /* The method allows to determine nullness of a complex expression without fully evaluating it, instead of calling val/result*() then checking null_value. Used in Item_func_isnull/Item_func_isnotnull and Item_sum_count/Item_sum_count_distinct. Any new item which can be NULL must implement this method. */ virtual bool is_null() { return 0; } /* Make sure the null_value member has a correct value. */ virtual void update_null_value () { (void) val_int(); } /* Inform the item that there will be no distinction between its result being FALSE or NULL. NOTE This function will be called for eg. Items that are top-level AND-parts of the WHERE clause. Items implementing this function (currently Item_cond_and and subquery-related item) enable special optimizations when they are "top level". */ virtual void top_level_item() {} /* set field of temporary table for Item which can be switched on temporary table during query processing (grouping and so on) */ virtual void set_result_field(Field *field) {} virtual bool is_result_field() { return 0; } virtual bool is_bool_func() { return 0; } virtual void save_in_result_field(bool no_conversions) {} /* set value of aggregate function in case of no rows for grouping were found */ virtual void no_rows_in_result() {} virtual void restore_to_before_no_rows_in_result() {} virtual Item *copy_or_same(THD *thd) { return this; } virtual Item *copy_andor_structure(THD *thd) { return this; } virtual Item *real_item() { return this; } virtual Item *get_tmp_table_item(THD *thd) { return copy_or_same(thd); } static CHARSET_INFO *default_charset(); virtual CHARSET_INFO *compare_collation() { return NULL; } /* For backward compatibility, to make numeric data types return "binary" charset in client-side metadata. */ virtual CHARSET_INFO *charset_for_protocol(void) const { return result_type() == STRING_RESULT ? collation.collation : &my_charset_bin; }; virtual bool walk(Item_processor processor, bool walk_subquery, uchar *arg) { return (this->*processor)(arg); } virtual Item* transform(Item_transformer transformer, uchar *arg); /* This function performs a generic "compilation" of the Item tree. The process of compilation is assumed to go as follows: compile() { if (this->*some_analyzer(...)) { compile children if any; this->*some_transformer(...); } } i.e. analysis is performed top-down while transformation is done bottom-up. */ virtual Item* compile(Item_analyzer analyzer, uchar **arg_p, Item_transformer transformer, uchar *arg_t) { if ((this->*analyzer) (arg_p)) return ((this->*transformer) (arg_t)); return 0; } virtual void traverse_cond(Cond_traverser traverser, void *arg, traverse_order order) { (*traverser)(this, arg); } /* This is used to get the most recent version of any function in an item tree. The version is the version where a MySQL function was introduced in. So any function which is added should use this function and set the int_arg to maximum of the input data and their own version info. */ virtual bool intro_version(uchar *int_arg) { return 0; } virtual bool remove_dependence_processor(uchar * arg) { return 0; } virtual bool remove_fixed(uchar * arg) { fixed= 0; return 0; } virtual bool cleanup_processor(uchar *arg); virtual bool collect_item_field_processor(uchar * arg) { return 0; } virtual bool add_field_to_set_processor(uchar * arg) { return 0; } virtual bool find_item_in_field_list_processor(uchar *arg) { return 0; } virtual bool change_context_processor(uchar *context) { return 0; } virtual bool reset_query_id_processor(uchar *query_id_arg) { return 0; } virtual bool is_expensive_processor(uchar *arg) { return 0; } virtual bool register_field_in_read_map(uchar *arg) { return 0; } virtual bool register_field_in_write_map(uchar *arg) { return 0; } virtual bool enumerate_field_refs_processor(uchar *arg) { return 0; } virtual bool mark_as_eliminated_processor(uchar *arg) { return 0; } virtual bool eliminate_subselect_processor(uchar *arg) { return 0; } virtual bool set_fake_select_as_master_processor(uchar *arg) { return 0; } virtual bool update_table_bitmaps_processor(uchar *arg) { return 0; } virtual bool view_used_tables_processor(uchar *arg) { return 0; } virtual bool eval_not_null_tables(uchar *opt_arg) { return 0; } virtual bool clear_sum_processor(uchar *opt_arg) { return 0; } virtual bool is_subquery_processor (uchar *opt_arg) { return 0; } /* To call bool function for all arguments */ struct bool_func_call_args { Item *original_func_item; void (Item::*bool_function)(); }; bool call_bool_func_processor(uchar *org_item) { bool_func_call_args *info= (bool_func_call_args*) org_item; /* Avoid recursion, as walk also calls for original item */ if (info->original_func_item != this) (this->*(info->bool_function))(); return FALSE; } /* The next function differs from the previous one that a bitmap to be updated is passed as uchar *arg. */ virtual bool register_field_in_bitmap(uchar *arg) { return 0; } bool cache_const_expr_analyzer(uchar **arg); Item* cache_const_expr_transformer(uchar *arg); /* Check if a partition function is allowed SYNOPSIS check_partition_func_processor() int_arg Ignored RETURN VALUE TRUE Partition function not accepted FALSE Partition function accepted DESCRIPTION check_partition_func_processor is used to check if a partition function uses an allowed function. An allowed function will always ensure that X=Y guarantees that also part_function(X)=part_function(Y) where X is a set of partition fields and so is Y. The problems comes mainly from character sets where two equal strings can be quite unequal. E.g. the german character for double s is equal to 2 s. The default is that an item is not allowed in a partition function. Allowed functions can never depend on server version, they cannot depend on anything related to the environment. They can also only depend on a set of fields in the table itself. They cannot depend on other tables and cannot contain any queries and cannot contain udf's or similar. If a new Item class is defined and it inherits from a class that is allowed in a partition function then it is very important to consider whether this should be inherited to the new class. If not the function below should be defined in the new Item class. The general behaviour is that most integer functions are allowed. If the partition function contains any multi-byte collations then the function check_part_func_fields will report an error on the partition function independent of what functions are used. So the only character sets allowed are single character collation and even for those only a limited set of functions are allowed. The problem with multi-byte collations is that almost every string function has the ability to change things such that two strings that are equal will not be equal after manipulated by a string function. E.g. two strings one contains a double s, there is a special german character that is equal to two s. Now assume a string function removes one character at this place, then in one the double s will be removed and in the other there will still be one s remaining and the strings are no longer equal and thus the partition function will not sort equal strings into the same partitions. So the check if a partition function is valid is two steps. First check that the field types are valid, next check that the partition function is valid. The current set of partition functions valid assumes that there are no multi-byte collations amongst the partition fields. */ virtual bool check_partition_func_processor(uchar *bool_arg) { return TRUE;} /* @brief Processor used to mark virtual columns used in partitioning expression @param arg always ignored @retval FALSE always */ virtual bool vcol_in_partition_func_processor(uchar *arg) { return FALSE; } /* The enumeration Subst_constraint is currently used only in implementations of the virtual function subst_argument_checker. */ enum Subst_constraint { NO_SUBST= 0, /* No substitution for a field is allowed */ ANY_SUBST, /* Any substitution for a field is allowed */ IDENTITY_SUBST /* Substitution for a field is allowed if any two different values of the field type are not equal */ }; virtual bool subst_argument_checker(uchar **arg) { return (*arg != NULL); } /* @brief Processor used to check acceptability of an item in the defining expression for a virtual column @param arg always ignored @retval FALSE the item is accepted in the definition of a virtual column @retval TRUE otherwise */ virtual bool check_vcol_func_processor(uchar *arg) { return trace_unsupported_by_check_vcol_func_processor(full_name()); } virtual Item *equal_fields_propagator(uchar * arg) { return this; } virtual bool set_no_const_sub(uchar *arg) { return FALSE; } virtual Item *replace_equal_field(uchar * arg) { return this; } /* Check if an expression value has allowed arguments, like DATE/DATETIME for date functions. Also used by partitioning code to reject timezone-dependent expressions in a (sub)partitioning function. */ virtual bool check_valid_arguments_processor(uchar *bool_arg) { return FALSE; } struct Collect_deps_prm { List *parameters; /* unit from which we count nest_level */ st_select_lex_unit *nest_level_base; int nest_level; }; /** Collect outer references */ virtual bool collect_outer_ref_processor(uchar *arg) {return FALSE; } /** Find a function of a given type @param arg the function type to search (enum Item_func::Functype) @return @retval TRUE the function type we're searching for is found @retval FALSE the function type wasn't found @description This function can be used (together with Item::walk()) to find functions in an item tree fragment. */ virtual bool find_function_processor (uchar *arg) { return FALSE; } virtual bool check_inner_refs_processor(uchar *arg) { return FALSE; } /* For SP local variable returns pointer to Item representing its current value and pointer to current Item otherwise. */ virtual Item *this_item() { return this; } virtual const Item *this_item() const { return this; } /* For SP local variable returns address of pointer to Item representing its current value and pointer passed via parameter otherwise. */ virtual Item **this_item_addr(THD *thd, Item **addr_arg) { return addr_arg; } // Row emulation virtual uint cols() { return 1; } virtual Item* element_index(uint i) { return this; } virtual Item** addr(uint i) { return 0; } virtual bool check_cols(uint c); // It is not row => null inside is impossible virtual bool null_inside() { return 0; } // used in row subselects to get value of elements virtual void bring_value() {} Field *tmp_table_field_from_field_type(TABLE *table, bool fixed_length); virtual Item_field *filed_for_view_update() { return 0; } virtual Item *neg_transformer(THD *thd) { return NULL; } virtual Item *update_value_transformer(uchar *select_arg) { return this; } virtual Item *expr_cache_insert_transformer(uchar *thd_arg) { return this; } virtual bool expr_cache_is_needed(THD *) { return FALSE; } virtual Item *safe_charset_converter(CHARSET_INFO *tocs); void delete_self() { cleanup(); delete this; } virtual bool is_splocal() { return 0; } /* Needed for error checking */ /* Return Settable_routine_parameter interface of the Item. Return 0 if this Item is not Settable_routine_parameter. */ virtual Settable_routine_parameter *get_settable_routine_parameter() { return 0; } /** Check whether this and the given item has compatible comparison context. Used by the equality propagation. See Item_field::equal_fields_propagator. @return TRUE if the context is the same FALSE otherwise. */ inline bool has_compatible_context(Item *item) const { return cmp_context == IMPOSSIBLE_RESULT || item->cmp_context == cmp_context; } /* Test whether an expression is expensive to compute. Used during optimization to avoid computing expensive expressions during this phase. Also used to force temp tables when sorting on expensive functions. TODO: Normally we should have a method: cost Item::execution_cost(), where 'cost' is either 'double' or some structure of various cost parameters. NOTE This function is now used to prevent evaluation of materialized IN subquery predicates before it is allowed. grep for DontEvaluateMaterializedSubqueryTooEarly to see the uses. */ virtual bool is_expensive() { if (is_expensive_cache < 0) is_expensive_cache= walk(&Item::is_expensive_processor, 0, (uchar*)0); return test(is_expensive_cache); } virtual Field::geometry_type get_geometry_type() const { return Field::GEOM_GEOMETRY; }; String *check_well_formed_result(String *str, bool send_error= 0); bool eq_by_collation(Item *item, bool binary_cmp, CHARSET_INFO *cs); uint32 max_char_length() const { return max_length / collation.collation->mbmaxlen; } void fix_length_and_charset(uint32 max_char_length_arg, CHARSET_INFO *cs) { max_length= char_to_byte_length_safe(max_char_length_arg, cs->mbmaxlen); collation.collation= cs; } void fix_char_length(uint32 max_char_length_arg) { max_length= char_to_byte_length_safe(max_char_length_arg, collation.collation->mbmaxlen); } void fix_char_length_ulonglong(ulonglong max_char_length_arg) { ulonglong max_result_length= max_char_length_arg * collation.collation->mbmaxlen; if (max_result_length >= MAX_BLOB_WIDTH) { max_length= MAX_BLOB_WIDTH; maybe_null= 1; } else max_length= (uint32) max_result_length; } /* Return TRUE if the item points to a column of an outer-joined table. */ virtual bool is_outer_field() const { DBUG_ASSERT(fixed); return FALSE; } Item* set_expr_cache(THD *thd); virtual Item *get_cached_item() { return NULL; } virtual Item_equal *get_item_equal() { return NULL; } virtual void set_item_equal(Item_equal *item_eq) {}; virtual Item_equal *find_item_equal(COND_EQUAL *cond_equal) { return NULL; } /** Set the join tab index to the minimal (left-most) JOIN_TAB to which this Item is attached. The number is an index is depth_first_tab() traversal order. */ virtual void set_join_tab_idx(uint join_tab_idx_arg) { if (join_tab_idx_arg < join_tab_idx) join_tab_idx= join_tab_idx_arg; } virtual uint get_join_tab_idx() { return join_tab_idx; } table_map view_used_tables(TABLE_LIST *view) { view->view_used_tables= 0; walk(&Item::view_used_tables_processor, 0, (uchar *) view); return view->view_used_tables; } /** Collect and add to the list cache parameters for this Item. @note Now implemented only for subqueries and in_optimizer, if we need it for general function then this method should be defined for Item_func. */ virtual void get_cache_parameters(List ¶meters) { }; virtual void mark_as_condition_AND_part(TABLE_LIST *embedding) {}; }; /** Compare two Items for List::add_unique() */ bool cmp_items(Item *a, Item *b); /* Class to be used to enumerate all field references in an item tree. This includes references to outside but not fields of the tables within a subquery. Suggested usage: class My_enumerator : public Field_enumerator { virtual void visit_field() { ... your actions ...} } My_enumerator enumerator; item->walk(Item::enumerate_field_refs_processor, ...,(uchar*)&enumerator); This is similar to Visitor pattern. */ class Field_enumerator { public: virtual void visit_field(Item_field *field)= 0; virtual ~Field_enumerator() {}; /* purecov: inspected */ Field_enumerator() {} /* Remove gcc warning */ }; class sp_head; class Item_basic_constant :public Item { table_map used_table_map; public: Item_basic_constant(): Item(), used_table_map(0) {}; void set_used_tables(table_map map) { used_table_map= map; } table_map used_tables() const { return used_table_map; } /* to prevent drop fixed flag (no need parent cleanup call) */ void cleanup() { /* Restore the original field name as it might not have been allocated in the statement memory. If the name is auto generated, it must be done again between subsequent executions of a prepared statement. */ if (orig_name) name= orig_name; } }; /***************************************************************************** The class is a base class for representation of stored routine variables in the Item-hierarchy. There are the following kinds of SP-vars: - local variables (Item_splocal); - CASE expression (Item_case_expr); *****************************************************************************/ class Item_sp_variable :public Item { protected: /* THD, which is stored in fix_fields() and is used in this_item() to avoid current_thd use. */ THD *m_thd; public: LEX_STRING m_name; public: #ifndef DBUG_OFF /* Routine to which this Item_splocal belongs. Used for checking if correct runtime context is used for variable handling. */ sp_head *m_sp; #endif public: Item_sp_variable(char *sp_var_name_str, uint sp_var_name_length); public: bool fix_fields(THD *thd, Item **); double val_real(); longlong val_int(); String *val_str(String *sp); my_decimal *val_decimal(my_decimal *decimal_value); bool is_null(); public: inline void make_field(Send_field *field); inline bool const_item() const; inline int save_in_field(Field *field, bool no_conversions); inline bool send(Protocol *protocol, String *str); }; /***************************************************************************** Item_sp_variable inline implementation. *****************************************************************************/ inline void Item_sp_variable::make_field(Send_field *field) { Item *it= this_item(); if (name) it->set_name(name, (uint) strlen(name), system_charset_info); else it->set_name(m_name.str, (uint) m_name.length, system_charset_info); it->make_field(field); } inline bool Item_sp_variable::const_item() const { return TRUE; } inline int Item_sp_variable::save_in_field(Field *field, bool no_conversions) { return this_item()->save_in_field(field, no_conversions); } inline bool Item_sp_variable::send(Protocol *protocol, String *str) { return this_item()->send(protocol, str); } /***************************************************************************** A reference to local SP variable (incl. reference to SP parameter), used in runtime. *****************************************************************************/ class Item_splocal :public Item_sp_variable, private Settable_routine_parameter { uint m_var_idx; Type m_type; Item_result m_result_type; enum_field_types m_field_type; public: /* Is this variable a parameter in LIMIT clause. Used only during NAME_CONST substitution, to not append NAME_CONST to the resulting query and thus not break the slave. */ bool limit_clause_param; /* Position of this reference to SP variable in the statement (the statement itself is in sp_instr_stmt::m_query). This is valid only for references to SP variables in statements, excluding DECLARE CURSOR statement. It is used to replace references to SP variables with NAME_CONST calls when putting statements into the binary log. Value of 0 means that this object doesn't corresponding to reference to SP variable in query text. */ uint pos_in_query; /* Byte length of SP variable name in the statement (see pos_in_query). The value of this field may differ from the name_length value because name_length contains byte length of UTF8-encoded item name, but the query string (see sp_instr_stmt::m_query) is currently stored with a charset from the SET NAMES statement. */ uint len_in_query; Item_splocal(const LEX_STRING &sp_var_name, uint sp_var_idx, enum_field_types sp_var_type, uint pos_in_q= 0, uint len_in_q= 0); bool is_splocal() { return 1; } /* Needed for error checking */ Item *this_item(); const Item *this_item() const; Item **this_item_addr(THD *thd, Item **); virtual void print(String *str, enum_query_type query_type); public: inline const LEX_STRING *my_name() const; inline uint get_var_idx() const; inline enum Type type() const; inline Item_result result_type() const; inline enum_field_types field_type() const { return m_field_type; } private: bool set_value(THD *thd, sp_rcontext *ctx, Item **it); public: Settable_routine_parameter *get_settable_routine_parameter() { return this; } }; /***************************************************************************** Item_splocal inline implementation. *****************************************************************************/ inline const LEX_STRING *Item_splocal::my_name() const { return &m_name; } inline uint Item_splocal::get_var_idx() const { return m_var_idx; } inline enum Item::Type Item_splocal::type() const { return m_type; } inline Item_result Item_splocal::result_type() const { return m_result_type; } /***************************************************************************** A reference to case expression in SP, used in runtime. *****************************************************************************/ class Item_case_expr :public Item_sp_variable { public: Item_case_expr(uint case_expr_id); public: Item *this_item(); const Item *this_item() const; Item **this_item_addr(THD *thd, Item **); inline enum Type type() const; inline Item_result result_type() const; public: /* NOTE: print() is intended to be used from views and for debug. Item_case_expr can not occur in views, so here it is only for debug purposes. */ virtual void print(String *str, enum_query_type query_type); private: uint m_case_expr_id; }; /***************************************************************************** Item_case_expr inline implementation. *****************************************************************************/ inline enum Item::Type Item_case_expr::type() const { return this_item()->type(); } inline Item_result Item_case_expr::result_type() const { return this_item()->result_type(); } /* NAME_CONST(given_name, const_value). This 'function' has all properties of the supplied const_value (which is assumed to be a literal constant), and the name given_name. This is used to replace references to SP variables when we write PROCEDURE statements into the binary log. TODO Together with Item_splocal and Item::this_item() we can actually extract common a base of this class and Item_splocal. Maybe it is possible to extract a common base with class Item_ref, too. */ class Item_name_const : public Item { Item *value_item; Item *name_item; bool valid_args; public: Item_name_const(Item *name_arg, Item *val); bool fix_fields(THD *, Item **); enum Type type() const; double val_real(); longlong val_int(); String *val_str(String *sp); my_decimal *val_decimal(my_decimal *); bool is_null(); virtual void print(String *str, enum_query_type query_type); Item_result result_type() const { return value_item->result_type(); } bool const_item() const { return TRUE; } int save_in_field(Field *field, bool no_conversions) { return value_item->save_in_field(field, no_conversions); } bool send(Protocol *protocol, String *str) { return value_item->send(protocol, str); } bool check_vcol_func_processor(uchar *arg) { return trace_unsupported_by_check_vcol_func_processor("name_const"); } }; bool agg_item_collations(DTCollation &c, const char *name, Item **items, uint nitems, uint flags, int item_sep); bool agg_item_collations_for_comparison(DTCollation &c, const char *name, Item **items, uint nitems, uint flags); bool agg_item_set_converter(DTCollation &coll, const char *fname, Item **args, uint nargs, uint flags, int item_sep); bool agg_item_charsets(DTCollation &c, const char *name, Item **items, uint nitems, uint flags, int item_sep); inline bool agg_item_charsets_for_string_result(DTCollation &c, const char *name, Item **items, uint nitems, int item_sep= 1) { uint flags= MY_COLL_ALLOW_SUPERSET_CONV | MY_COLL_ALLOW_COERCIBLE_CONV | MY_COLL_ALLOW_NUMERIC_CONV; return agg_item_charsets(c, name, items, nitems, flags, item_sep); } inline bool agg_item_charsets_for_comparison(DTCollation &c, const char *name, Item **items, uint nitems, int item_sep= 1) { uint flags= MY_COLL_ALLOW_SUPERSET_CONV | MY_COLL_ALLOW_COERCIBLE_CONV | MY_COLL_DISALLOW_NONE; return agg_item_charsets(c, name, items, nitems, flags, item_sep); } inline bool agg_item_charsets_for_string_result_with_comparison(DTCollation &c, const char *name, Item **items, uint nitems, int item_sep= 1) { uint flags= MY_COLL_ALLOW_SUPERSET_CONV | MY_COLL_ALLOW_COERCIBLE_CONV | MY_COLL_ALLOW_NUMERIC_CONV | MY_COLL_DISALLOW_NONE; return agg_item_charsets(c, name, items, nitems, flags, item_sep); } class Item_num: public Item_basic_constant { public: Item_num() { collation.set_numeric(); } /* Remove gcc warning */ virtual Item_num *neg()= 0; Item *safe_charset_converter(CHARSET_INFO *tocs); bool check_partition_func_processor(uchar *int_arg) { return FALSE;} bool check_vcol_func_processor(uchar *arg) { return FALSE;} }; #define NO_CACHED_FIELD_INDEX ((uint)(-1)) class st_select_lex; class Item_ident :public Item { protected: /* We have to store initial values of db_name, table_name and field_name to be able to restore them during cleanup() because they can be updated during fix_fields() to values from Field object and life-time of those is shorter than life-time of Item_field. */ const char *orig_db_name; const char *orig_table_name; const char *orig_field_name; public: Name_resolution_context *context; const char *db_name; const char *table_name; const char *field_name; bool alias_name_used; /* true if item was resolved against alias */ /* Cached value of index for this field in table->field array, used by prep. stmts for speeding up their re-execution. Holds NO_CACHED_FIELD_INDEX if index value is not known. */ uint cached_field_index; /* Cached pointer to table which contains this field, used for the same reason by prep. stmt. too in case then we have not-fully qualified field. 0 - means no cached value. */ TABLE_LIST *cached_table; st_select_lex *depended_from; /* Some Items resolved in another select should not be marked as dependency of the subquery where they are. During normal name resolution, we check this. Stored procedures and prepared statements first try to resolve an ident item using a cached table reference and field position from the previous query execution (cached_table/cached_field_index). If the tables were not changed, the ident matches the table/field, and we have faster resolution of the ident without looking through all tables and fields in the query. But in this case, we can not check all conditions about this ident item dependency, so we should cache the condition in this variable. */ bool can_be_depended; Item_ident(Name_resolution_context *context_arg, const char *db_name_arg, const char *table_name_arg, const char *field_name_arg); Item_ident(THD *thd, Item_ident *item); Item_ident(TABLE_LIST *view_arg, const char *field_name_arg); const char *full_name() const; void cleanup(); st_select_lex *get_depended_from() const; bool remove_dependence_processor(uchar * arg); virtual void print(String *str, enum_query_type query_type); virtual bool change_context_processor(uchar *cntx) { context= (Name_resolution_context *)cntx; return FALSE; } /** Collect outer references */ virtual bool collect_outer_ref_processor(uchar *arg); friend bool insert_fields(THD *thd, Name_resolution_context *context, const char *db_name, const char *table_name, List_iterator *it, bool any_privileges); }; class Item_ident_for_show :public Item { public: Field *field; const char *db_name; const char *table_name; Item_ident_for_show(Field *par_field, const char *db_arg, const char *table_name_arg) :field(par_field), db_name(db_arg), table_name(table_name_arg) {} enum Type type() const { return FIELD_ITEM; } double val_real() { return field->val_real(); } longlong val_int() { return field->val_int(); } String *val_str(String *str) { return field->val_str(str); } my_decimal *val_decimal(my_decimal *dec) { return field->val_decimal(dec); } void make_field(Send_field *tmp_field); CHARSET_INFO *charset_for_protocol(void) const { return field->charset_for_protocol(); } }; class Item_field :public Item_ident { protected: void set_field(Field *field); public: Field *field,*result_field; Item_equal *item_equal; bool no_const_subst; /* if any_privileges set to TRUE then here real effective privileges will be stored */ uint have_privileges; /* field need any privileges (for VIEW creation) */ bool any_privileges; Item_field(Name_resolution_context *context_arg, const char *db_arg,const char *table_name_arg, const char *field_name_arg); /* Constructor needed to process subselect with temporary tables (see Item) */ Item_field(THD *thd, Item_field *item); /* Constructor used inside setup_wild(), ensures that field, table, and database names will live as long as Item_field (this is important in prepared statements). */ Item_field(THD *thd, Name_resolution_context *context_arg, Field *field); /* If this constructor is used, fix_fields() won't work, because db_name, table_name and column_name are unknown. It's necessary to call reset_field() before fix_fields() for all fields created this way. */ Item_field(Field *field); enum Type type() const { return FIELD_ITEM; } bool eq(const Item *item, bool binary_cmp) const; double val_real(); longlong val_int(); my_decimal *val_decimal(my_decimal *); String *val_str(String*); void save_result(Field *to); double val_result(); longlong val_int_result(); String *str_result(String* tmp); my_decimal *val_decimal_result(my_decimal *); bool val_bool_result(); bool is_null_result(); bool send(Protocol *protocol, String *str_arg); void reset_field(Field *f); bool fix_fields(THD *, Item **); void fix_after_pullout(st_select_lex *new_parent, Item **ref); void make_field(Send_field *tmp_field); int save_in_field(Field *field,bool no_conversions); void save_org_in_field(Field *field); table_map used_tables() const; table_map all_used_tables() const; enum Item_result result_type () const { return field->result_type(); } Item_result cast_to_int_type() const { return field->cmp_type(); } enum_field_types field_type() const { return field->type(); } enum_monotonicity_info get_monotonicity_info() const { return MONOTONIC_STRICT_INCREASING; } longlong val_int_endpoint(bool left_endp, bool *incl_endp); Field *get_tmp_table_field() { return result_field; } Field *tmp_table_field(TABLE *t_arg) { return result_field; } bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate); bool get_date_result(MYSQL_TIME *ltime,ulonglong fuzzydate); bool is_null() { return field->is_null(); } void update_null_value(); void update_table_bitmaps() { if (field && field->table) { TABLE *tab= field->table; tab->covering_keys.intersect(field->part_of_key); tab->merge_keys.merge(field->part_of_key); if (tab->read_set) bitmap_fast_test_and_set(tab->read_set, field->field_index); if (field->vcol_info) tab->mark_virtual_col(field); } } void update_used_tables() { update_table_bitmaps(); } Item *get_tmp_table_item(THD *thd); bool collect_item_field_processor(uchar * arg); bool add_field_to_set_processor(uchar * arg); bool find_item_in_field_list_processor(uchar *arg); bool register_field_in_read_map(uchar *arg); bool register_field_in_write_map(uchar *arg); bool register_field_in_bitmap(uchar *arg); bool check_partition_func_processor(uchar *int_arg) {return FALSE;} bool vcol_in_partition_func_processor(uchar *bool_arg); bool check_vcol_func_processor(uchar *arg) { return FALSE;} bool enumerate_field_refs_processor(uchar *arg); bool update_table_bitmaps_processor(uchar *arg); void cleanup(); Item_equal *get_item_equal() { return item_equal; } void set_item_equal(Item_equal *item_eq) { item_equal= item_eq; } Item_equal *find_item_equal(COND_EQUAL *cond_equal); bool subst_argument_checker(uchar **arg); Item *equal_fields_propagator(uchar *arg); bool set_no_const_sub(uchar *arg); Item *replace_equal_field(uchar *arg); inline uint32 max_disp_length() { return field->max_display_length(); } Item_field *filed_for_view_update() { return this; } Item *safe_charset_converter(CHARSET_INFO *tocs); int fix_outer_field(THD *thd, Field **field, Item **reference); virtual Item *update_value_transformer(uchar *select_arg); virtual void print(String *str, enum_query_type query_type); bool is_outer_field() const { DBUG_ASSERT(fixed); return field->table->pos_in_table_list->outer_join; } Field::geometry_type get_geometry_type() const { DBUG_ASSERT(field_type() == MYSQL_TYPE_GEOMETRY); return field->get_geometry_type(); } CHARSET_INFO *charset_for_protocol(void) const { return field->charset_for_protocol(); } friend class Item_default_value; friend class Item_insert_value; friend class st_select_lex_unit; }; class Item_null :public Item_basic_constant { public: Item_null(char *name_par=0) { maybe_null= null_value= TRUE; max_length= 0; name= name_par ? name_par : (char*) "NULL"; fixed= 1; collation.set(&my_charset_bin, DERIVATION_IGNORABLE); } enum Type type() const { return NULL_ITEM; } bool eq(const Item *item, bool binary_cmp) const; double val_real(); longlong val_int(); String *val_str(String *str); my_decimal *val_decimal(my_decimal *); int save_in_field(Field *field, bool no_conversions); int save_safe_in_field(Field *field); bool send(Protocol *protocol, String *str); enum Item_result result_type () const { return STRING_RESULT; } enum_field_types field_type() const { return MYSQL_TYPE_NULL; } bool basic_const_item() const { return 1; } Item *clone_item() { return new Item_null(name); } bool is_null() { return 1; } virtual inline void print(String *str, enum_query_type query_type) { str->append(STRING_WITH_LEN("NULL")); } Item *safe_charset_converter(CHARSET_INFO *tocs); bool check_partition_func_processor(uchar *int_arg) {return FALSE;} bool check_vcol_func_processor(uchar *arg) { return FALSE;} }; class Item_null_result :public Item_null { public: Field *result_field; Item_null_result() : Item_null(), result_field(0) {} bool is_result_field() { return result_field != 0; } void save_in_result_field(bool no_conversions) { save_in_field(result_field, no_conversions); } bool check_partition_func_processor(uchar *int_arg) {return TRUE;} bool check_vcol_func_processor(uchar *arg) { return trace_unsupported_by_check_vcol_func_processor(full_name()); } }; /* Item represents one placeholder ('?') of prepared statement */ class Item_param :public Item, private Settable_routine_parameter { char cnvbuf[MAX_FIELD_WIDTH]; String cnvstr; Item *cnvitem; public: enum enum_item_param_state { NO_VALUE, NULL_VALUE, INT_VALUE, REAL_VALUE, STRING_VALUE, TIME_VALUE, LONG_DATA_VALUE, DECIMAL_VALUE } state; /* A buffer for string and long data values. Historically all allocated values returned from val_str() were treated as eligible to modification. I. e. in some cases Item_func_concat can append it's second argument to return value of the first one. Because of that we can't return the original buffer holding string data from val_str(), and have to have one buffer for data and another just pointing to the data. This is the latter one and it's returned from val_str(). Can not be declared inside the union as it's not a POD type. */ String str_value_ptr; my_decimal decimal_value; union { longlong integer; double real; /* Character sets conversion info for string values. Character sets of client and connection defined at bind time are used for all conversions, even if one of them is later changed (i.e. between subsequent calls to mysql_stmt_execute). */ struct CONVERSION_INFO { CHARSET_INFO *character_set_client; CHARSET_INFO *character_set_of_placeholder; /* This points at character set of connection if conversion to it is required (i. e. if placeholder typecode is not BLOB). Otherwise it's equal to character_set_client (to simplify check in convert_str_value()). */ CHARSET_INFO *final_character_set_of_str_value; } cs_info; MYSQL_TIME time; } value; /* Cached values for virtual methods to save us one switch. */ enum Item_result item_result_type; enum Type item_type; /* Used when this item is used in a temporary table. This is NOT placeholder metadata sent to client, as this value is assigned after sending metadata (in setup_one_conversion_function). For example in case of 'SELECT ?' you'll get MYSQL_TYPE_STRING both in result set and placeholders metadata, no matter what type you will supply for this placeholder in mysql_stmt_execute. */ enum enum_field_types param_type; /* Offset of placeholder inside statement text. Used to create no-placeholders version of this statement for the binary log. */ uint pos_in_query; Item_param(uint pos_in_query_arg); enum Item_result result_type () const { return item_result_type; } enum Item_result cast_to_int_type() const { return item_result_type; } enum Type type() const { return item_type; } enum_field_types field_type() const { return param_type; } double val_real(); longlong val_int(); my_decimal *val_decimal(my_decimal*); String *val_str(String*); bool get_date(MYSQL_TIME *tm, ulonglong fuzzydate); int save_in_field(Field *field, bool no_conversions); void set_null(); void set_int(longlong i, uint32 max_length_arg); void set_double(double i); void set_decimal(const char *str, ulong length); void set_decimal(const my_decimal *dv); bool set_str(const char *str, ulong length); bool set_longdata(const char *str, ulong length); void set_time(MYSQL_TIME *tm, timestamp_type type, uint32 max_length_arg); bool set_from_user_var(THD *thd, const user_var_entry *entry); void reset(); /* Assign placeholder value from bind data. Note, that 'len' has different semantics in embedded library (as we don't need to check that packet is not broken there). See sql_prepare.cc for details. */ void (*set_param_func)(Item_param *param, uchar **pos, ulong len); const String *query_val_str(String *str) const; bool convert_str_value(THD *thd); /* If value for parameter was not set we treat it as non-const so noone will use parameters value in fix_fields still parameter is constant during execution. */ virtual table_map used_tables() const { return state != NO_VALUE ? (table_map)0 : PARAM_TABLE_BIT; } virtual void print(String *str, enum_query_type query_type); bool is_null() { DBUG_ASSERT(state != NO_VALUE); return state == NULL_VALUE; } bool basic_const_item() const; /* This method is used to make a copy of a basic constant item when propagating constants in the optimizer. The reason to create a new item and not use the existing one is not precisely known (2005/04/16). Probably we are trying to preserve tree structure of items, in other words, avoid pointing at one item from two different nodes of the tree. Return a new basic constant item if parameter value is a basic constant, assert otherwise. This method is called only if basic_const_item returned TRUE. */ Item *safe_charset_converter(CHARSET_INFO *tocs); Item *clone_item(); /* Implement by-value equality evaluation if parameter value is set and is a basic constant (integer, real or string). Otherwise return FALSE. */ bool eq(const Item *item, bool binary_cmp) const; /** Item is a argument to a limit clause. */ bool limit_clause_param; void set_param_type_and_swap_value(Item_param *from); private: virtual inline Settable_routine_parameter * get_settable_routine_parameter() { return this; } virtual bool set_value(THD *thd, sp_rcontext *ctx, Item **it); virtual void set_out_param_info(Send_field *info); public: virtual const Send_field *get_out_param_info() const; virtual void make_field(Send_field *field); private: Send_field *m_out_param_info; }; class Item_int :public Item_num { public: longlong value; Item_int(int32 i,uint length= MY_INT32_NUM_DECIMAL_DIGITS) :value((longlong) i) { max_length=length; fixed= 1; } Item_int(longlong i,uint length= MY_INT64_NUM_DECIMAL_DIGITS) :value(i) { max_length=length; fixed= 1; } Item_int(ulonglong i, uint length= MY_INT64_NUM_DECIMAL_DIGITS) :value((longlong)i) { max_length=length; fixed= 1; unsigned_flag= 1; } Item_int(const char *str_arg,longlong i,uint length) :value(i) { max_length=length; name=(char*) str_arg; fixed= 1; } Item_int(const char *str_arg, uint length=64); enum Type type() const { return INT_ITEM; } enum Item_result result_type () const { return INT_RESULT; } enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; } longlong val_int() { DBUG_ASSERT(fixed == 1); return value; } double val_real() { DBUG_ASSERT(fixed == 1); return (double) value; } my_decimal *val_decimal(my_decimal *); String *val_str(String*); int save_in_field(Field *field, bool no_conversions); bool basic_const_item() const { return 1; } Item *clone_item() { return new Item_int(name,value,max_length); } virtual void print(String *str, enum_query_type query_type); Item_num *neg() { value= -value; return this; } uint decimal_precision() const { return (uint)(max_length - test(value < 0)); } bool eq(const Item *, bool binary_cmp) const; bool check_partition_func_processor(uchar *bool_arg) { return FALSE;} bool check_vcol_func_processor(uchar *arg) { return FALSE;} }; class Item_uint :public Item_int { public: Item_uint(const char *str_arg, uint length); Item_uint(ulonglong i) :Item_int(i, 10) {} Item_uint(const char *str_arg, longlong i, uint length); double val_real() { DBUG_ASSERT(fixed == 1); return ulonglong2double((ulonglong)value); } String *val_str(String*); Item *clone_item() { return new Item_uint(name, value, max_length); } virtual void print(String *str, enum_query_type query_type); Item_num *neg (); uint decimal_precision() const { return max_length; } }; class Item_datetime :public Item_int { protected: MYSQL_TIME ltime; public: Item_datetime() :Item_int(0) { unsigned_flag=0; } int save_in_field(Field *field, bool no_conversions); longlong val_int(); double val_real() { return (double)val_int(); } void set(longlong packed); }; /* decimal (fixed point) constant */ class Item_decimal :public Item_num { protected: my_decimal decimal_value; public: Item_decimal(const char *str_arg, uint length, CHARSET_INFO *charset); Item_decimal(const char *str, const my_decimal *val_arg, uint decimal_par, uint length); Item_decimal(my_decimal *value_par); Item_decimal(longlong val, bool unsig); Item_decimal(double val, int precision, int scale); Item_decimal(const uchar *bin, int precision, int scale); enum Type type() const { return DECIMAL_ITEM; } enum Item_result result_type () const { return DECIMAL_RESULT; } enum_field_types field_type() const { return MYSQL_TYPE_NEWDECIMAL; } longlong val_int(); double val_real(); String *val_str(String*); my_decimal *val_decimal(my_decimal *val) { return &decimal_value; } int save_in_field(Field *field, bool no_conversions); bool basic_const_item() const { return 1; } Item *clone_item() { return new Item_decimal(name, &decimal_value, decimals, max_length); } virtual void print(String *str, enum_query_type query_type); Item_num *neg() { my_decimal_neg(&decimal_value); unsigned_flag= !decimal_value.sign(); return this; } uint decimal_precision() const { return decimal_value.precision(); } bool eq(const Item *, bool binary_cmp) const; void set_decimal_value(my_decimal *value_par); bool check_partition_func_processor(uchar *bool_arg) { return FALSE;} bool check_vcol_func_processor(uchar *arg) { return FALSE;} }; class Item_float :public Item_num { char *presentation; public: double value; // Item_real() :value(0) {} Item_float(const char *str_arg, uint length); Item_float(const char *str,double val_arg,uint decimal_par,uint length) :value(val_arg) { presentation= name=(char*) str; decimals=(uint8) decimal_par; max_length=length; fixed= 1; } Item_float(double value_par, uint decimal_par) :presentation(0), value(value_par) { decimals= (uint8) decimal_par; fixed= 1; } int save_in_field(Field *field, bool no_conversions); enum Type type() const { return REAL_ITEM; } enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; } double val_real() { DBUG_ASSERT(fixed == 1); return value; } longlong val_int() { DBUG_ASSERT(fixed == 1); if (value <= (double) LONGLONG_MIN) { return LONGLONG_MIN; } else if (value >= (double) (ulonglong) LONGLONG_MAX) { return LONGLONG_MAX; } return (longlong) rint(value); } String *val_str(String*); my_decimal *val_decimal(my_decimal *); bool basic_const_item() const { return 1; } Item *clone_item() { return new Item_float(name, value, decimals, max_length); } Item_num *neg() { value= -value; return this; } virtual void print(String *str, enum_query_type query_type); bool eq(const Item *, bool binary_cmp) const; }; class Item_static_float_func :public Item_float { const char *func_name; public: Item_static_float_func(const char *str, double val_arg, uint decimal_par, uint length) :Item_float(NullS, val_arg, decimal_par, length), func_name(str) {} virtual inline void print(String *str, enum_query_type query_type) { str->append(func_name); } Item *safe_charset_converter(CHARSET_INFO *tocs); }; class Item_string :public Item_basic_constant { public: Item_string(const char *str,uint length, CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE, uint repertoire= MY_REPERTOIRE_UNICODE30) : m_cs_specified(FALSE) { str_value.set_or_copy_aligned(str, length, cs); collation.set(cs, dv, repertoire); /* We have to have a different max_length than 'length' here to ensure that we get the right length if we do use the item to create a new table. In this case max_length must be the maximum number of chars for a string of this type because we in Create_field:: divide the max_length with mbmaxlen). */ max_length= str_value.numchars()*cs->mbmaxlen; set_name(str, length, cs); decimals=NOT_FIXED_DEC; // it is constant => can be used without fix_fields (and frequently used) fixed= 1; } /* Just create an item and do not fill string representation */ Item_string(CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE) : m_cs_specified(FALSE) { collation.set(cs, dv); max_length= 0; set_name(NULL, 0, cs); decimals= NOT_FIXED_DEC; fixed= 1; } Item_string(const char *name_par, const char *str, uint length, CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE, uint repertoire= MY_REPERTOIRE_UNICODE30) : m_cs_specified(FALSE) { str_value.set_or_copy_aligned(str, length, cs); collation.set(cs, dv, repertoire); max_length= str_value.numchars()*cs->mbmaxlen; set_name(name_par, 0, cs); decimals=NOT_FIXED_DEC; // it is constant => can be used without fix_fields (and frequently used) fixed= 1; } /* This is used in stored procedures to avoid memory leaks and does a deep copy of its argument. */ void set_str_with_copy(const char *str_arg, uint length_arg) { str_value.copy(str_arg, length_arg, collation.collation); max_length= str_value.numchars() * collation.collation->mbmaxlen; } void set_repertoire_from_value() { collation.repertoire= my_string_repertoire(str_value.charset(), str_value.ptr(), str_value.length()); } enum Type type() const { return STRING_ITEM; } double val_real(); longlong val_int(); String *val_str(String*) { DBUG_ASSERT(fixed == 1); return (String*) &str_value; } my_decimal *val_decimal(my_decimal *); int save_in_field(Field *field, bool no_conversions); enum Item_result result_type () const { return STRING_RESULT; } enum_field_types field_type() const { return MYSQL_TYPE_VARCHAR; } bool basic_const_item() const { return 1; } bool eq(const Item *item, bool binary_cmp) const; Item *clone_item() { return new Item_string(name, str_value.ptr(), str_value.length(), collation.collation); } Item *safe_charset_converter(CHARSET_INFO *tocs); inline void append(char *str, uint length) { str_value.append(str, length); max_length= str_value.numchars() * collation.collation->mbmaxlen; } virtual void print(String *str, enum_query_type query_type); bool check_partition_func_processor(uchar *int_arg) {return FALSE;} bool check_vcol_func_processor(uchar *arg) { return FALSE;} /** Return TRUE if character-set-introducer was explicitly specified in the original query for this item (text literal). This operation is to be called from Item_string::print(). The idea is that when a query is generated (re-constructed) from the Item-tree, character-set-introducers should appear only for those literals, where they were explicitly specified by the user. Otherwise, that may lead to loss collation information (character set introducers implies default collation for the literal). Basically, that makes sense only for views and hopefully will be gone one day when we start using original query as a view definition. @return This operation returns the value of m_cs_specified attribute. @retval TRUE if character set introducer was explicitly specified in the original query. @retval FALSE otherwise. */ inline bool is_cs_specified() const { return m_cs_specified; } /** Set the value of m_cs_specified attribute. m_cs_specified attribute shows whether character-set-introducer was explicitly specified in the original query for this text literal or not. The attribute makes sense (is used) only for views. This operation is to be called from the parser during parsing an input query. */ inline void set_cs_specified(bool cs_specified) { m_cs_specified= cs_specified; } private: bool m_cs_specified; }; longlong longlong_from_string_with_check(CHARSET_INFO *cs, const char *cptr, const char *end); double double_from_string_with_check(CHARSET_INFO *cs, const char *cptr, const char *end); class Item_static_string_func :public Item_string { const char *func_name; public: Item_static_string_func(const char *name_par, const char *str, uint length, CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE) :Item_string(NullS, str, length, cs, dv), func_name(name_par) {} Item *safe_charset_converter(CHARSET_INFO *tocs); virtual inline void print(String *str, enum_query_type query_type) { str->append(func_name); } bool check_partition_func_processor(uchar *int_arg) {return TRUE;} bool check_vcol_func_processor(uchar *arg) { return trace_unsupported_by_check_vcol_func_processor(func_name); } }; /* for show tables */ class Item_partition_func_safe_string: public Item_string { public: Item_partition_func_safe_string(const char *name_arg, uint length, CHARSET_INFO *cs= NULL): Item_string(name_arg, length, cs) {} bool check_vcol_func_processor(uchar *arg) { return trace_unsupported_by_check_vcol_func_processor("safe_string"); } }; class Item_return_date_time :public Item_partition_func_safe_string { enum_field_types date_time_field_type; public: Item_return_date_time(const char *name_arg, uint length_arg, enum_field_types field_type_arg) :Item_partition_func_safe_string(name_arg, length_arg, &my_charset_bin), date_time_field_type(field_type_arg) { decimals= 0; } enum_field_types field_type() const { return date_time_field_type; } }; class Item_blob :public Item_partition_func_safe_string { public: Item_blob(const char *name_arg, uint length) : Item_partition_func_safe_string(name_arg, length, &my_charset_bin) { max_length= length; } enum Type type() const { return TYPE_HOLDER; } enum_field_types field_type() const { return MYSQL_TYPE_BLOB; } }; /** Item_empty_string -- is a utility class to put an item into List which is then used in protocol.send_result_set_metadata() when sending SHOW output to the client. */ class Item_empty_string :public Item_partition_func_safe_string { public: Item_empty_string(const char *header,uint length, CHARSET_INFO *cs= NULL) : Item_partition_func_safe_string("",0, cs ? cs : &my_charset_utf8_general_ci) { name=(char*) header; max_length= length * collation.collation->mbmaxlen; } void make_field(Send_field *field); }; class Item_return_int :public Item_int { enum_field_types int_field_type; public: Item_return_int(const char *name_arg, uint length, enum_field_types field_type_arg, longlong value_arg= 0) :Item_int(name_arg, value_arg, length), int_field_type(field_type_arg) { unsigned_flag=1; } enum_field_types field_type() const { return int_field_type; } }; class Item_hex_string: public Item_basic_constant { public: Item_hex_string(); Item_hex_string(const char *str,uint str_length); enum Type type() const { return VARBIN_ITEM; } double val_real() { DBUG_ASSERT(fixed == 1); return (double) (ulonglong) Item_hex_string::val_int(); } longlong val_int(); bool basic_const_item() const { return 1; } String *val_str(String*) { DBUG_ASSERT(fixed == 1); return &str_value; } my_decimal *val_decimal(my_decimal *); int save_in_field(Field *field, bool no_conversions); enum Item_result result_type () const { return STRING_RESULT; } enum Item_result cast_to_int_type() const { return INT_RESULT; } enum_field_types field_type() const { return MYSQL_TYPE_VARCHAR; } virtual void print(String *str, enum_query_type query_type); bool eq(const Item *item, bool binary_cmp) const; virtual Item *safe_charset_converter(CHARSET_INFO *tocs); bool check_partition_func_processor(uchar *int_arg) {return FALSE;} bool check_vcol_func_processor(uchar *arg) { return FALSE;} private: void hex_string_init(const char *str, uint str_length); }; class Item_bin_string: public Item_hex_string { public: Item_bin_string(const char *str,uint str_length); }; class Item_result_field :public Item /* Item with result field */ { public: Field *result_field; /* Save result here */ Item_result_field() :result_field(0) {} // Constructor used for Item_sum/Item_cond_and/or (see Item comment) Item_result_field(THD *thd, Item_result_field *item): Item(thd, item), result_field(item->result_field) {} ~Item_result_field() {} /* Required with gcc 2.95 */ Field *get_tmp_table_field() { return result_field; } Field *tmp_table_field(TABLE *t_arg) { return result_field; } table_map used_tables() const { return 1; } virtual void fix_length_and_dec()=0; void set_result_field(Field *field) { result_field= field; } bool is_result_field() { return 1; } void save_in_result_field(bool no_conversions) { save_in_field(result_field, no_conversions); } void cleanup(); bool check_vcol_func_processor(uchar *arg) { return FALSE;} /* This method is used for debug purposes to print the name of an item to the debug log. The second use of this method is as a helper function of print() and error messages, where it is applicable. To suit both goals it should return a meaningful, distinguishable and sintactically correct string. This method should not be used for runtime type identification, use enum {Sum}Functype and Item_func::functype()/Item_sum::sum_func() instead. Added here, to the parent class of both Item_func and Item_sum_func. NOTE: for Items inherited from Item_sum, func_name() return part of function name till first argument (including '(') to make difference in names for functions with 'distinct' clause and without 'distinct' and also to make printing of items inherited from Item_sum uniform. */ virtual const char *func_name() const= 0; }; class Item_ref :public Item_ident { protected: void set_properties(); public: enum Ref_Type { REF, DIRECT_REF, VIEW_REF, OUTER_REF, AGGREGATE_REF }; Field *result_field; /* Save result here */ Item **ref; bool reference_trough_name; Item_ref(Name_resolution_context *context_arg, const char *db_arg, const char *table_name_arg, const char *field_name_arg) :Item_ident(context_arg, db_arg, table_name_arg, field_name_arg), result_field(0), ref(0), reference_trough_name(1) {} /* This constructor is used in two scenarios: A) *item = NULL No initialization is performed, fix_fields() call will be necessary. B) *item points to an Item this Item_ref will refer to. This is used for GROUP BY. fix_fields() will not be called in this case, so we call set_properties to make this item "fixed". set_properties performs a subset of action Item_ref::fix_fields does, and this subset is enough for Item_ref's used in GROUP BY. TODO we probably fix a superset of problems like in BUG#6658. Check this with Bar, and if we have a more broader set of problems like this. */ Item_ref(Name_resolution_context *context_arg, Item **item, const char *table_name_arg, const char *field_name_arg, bool alias_name_used_arg= FALSE); Item_ref(TABLE_LIST *view_arg, Item **item, const char *field_name_arg, bool alias_name_used_arg= FALSE); /* Constructor need to process subselect with temporary tables (see Item) */ Item_ref(THD *thd, Item_ref *item) :Item_ident(thd, item), result_field(item->result_field), ref(item->ref) {} enum Type type() const { return REF_ITEM; } enum Type real_type() const { return ref ? (*ref)->type() : REF_ITEM; } bool eq(const Item *item, bool binary_cmp) const { Item *it= ((Item *) item)->real_item(); return ref && (*ref)->eq(it, binary_cmp); } void save_val(Field *to); void save_result(Field *to); double val_real(); longlong val_int(); my_decimal *val_decimal(my_decimal *); bool val_bool(); String *val_str(String* tmp); bool is_null(); bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate); double val_result(); longlong val_int_result(); String *str_result(String* tmp); my_decimal *val_decimal_result(my_decimal *); bool val_bool_result(); bool is_null_result(); bool send(Protocol *prot, String *tmp); void make_field(Send_field *field); bool fix_fields(THD *, Item **); void fix_after_pullout(st_select_lex *new_parent, Item **ref); int save_in_field(Field *field, bool no_conversions); void save_org_in_field(Field *field); enum Item_result result_type () const { return (*ref)->result_type(); } enum_field_types field_type() const { return (*ref)->field_type(); } Field *get_tmp_table_field() { return result_field ? result_field : (*ref)->get_tmp_table_field(); } Item *get_tmp_table_item(THD *thd); table_map used_tables() const; void update_used_tables(); bool const_item() const { return (*ref)->const_item(); } table_map not_null_tables() const { return depended_from ? 0 : (*ref)->not_null_tables(); } void set_result_field(Field *field) { result_field= field; } bool is_result_field() { return 1; } void save_in_result_field(bool no_conversions) { (*ref)->save_in_field(result_field, no_conversions); } Item *real_item() { return ref ? (*ref)->real_item() : this; } bool walk(Item_processor processor, bool walk_subquery, uchar *arg) { if (ref && *ref) return (*ref)->walk(processor, walk_subquery, arg) || (this->*processor)(arg); else return FALSE; } Item* transform(Item_transformer, uchar *arg); Item* compile(Item_analyzer analyzer, uchar **arg_p, Item_transformer transformer, uchar *arg_t); bool enumerate_field_refs_processor(uchar *arg) { return (*ref)->enumerate_field_refs_processor(arg); } void no_rows_in_result() { (*ref)->no_rows_in_result(); } void restore_to_before_no_rows_in_result() { (*ref)->restore_to_before_no_rows_in_result(); } virtual void print(String *str, enum_query_type query_type); void cleanup(); Item_field *filed_for_view_update() { return (*ref)->filed_for_view_update(); } virtual Ref_Type ref_type() { return REF; } // Row emulation: forwarding of ROW-related calls to ref uint cols() { return ref && result_type() == ROW_RESULT ? (*ref)->cols() : 1; } Item* element_index(uint i) { return ref && result_type() == ROW_RESULT ? (*ref)->element_index(i) : this; } Item** addr(uint i) { return ref && result_type() == ROW_RESULT ? (*ref)->addr(i) : 0; } bool check_cols(uint c) { return ref && result_type() == ROW_RESULT ? (*ref)->check_cols(c) : Item::check_cols(c); } bool null_inside() { return ref && result_type() == ROW_RESULT ? (*ref)->null_inside() : 0; } void bring_value() { if (ref && result_type() == ROW_RESULT) (*ref)->bring_value(); } bool check_vcol_func_processor(uchar *arg) { return trace_unsupported_by_check_vcol_func_processor("ref"); } bool basic_const_item() const { return ref && (*ref)->basic_const_item(); } bool is_outer_field() const { DBUG_ASSERT(fixed); DBUG_ASSERT(ref); return (*ref)->is_outer_field(); } }; /* The same as Item_ref, but get value from val_* family of method to get value of item on which it referred instead of result* family. */ class Item_direct_ref :public Item_ref { public: Item_direct_ref(Name_resolution_context *context_arg, Item **item, const char *table_name_arg, const char *field_name_arg, bool alias_name_used_arg= FALSE) :Item_ref(context_arg, item, table_name_arg, field_name_arg, alias_name_used_arg) {} /* Constructor need to process subselect with temporary tables (see Item) */ Item_direct_ref(THD *thd, Item_direct_ref *item) : Item_ref(thd, item) {} Item_direct_ref(TABLE_LIST *view_arg, Item **item, const char *field_name_arg, bool alias_name_used_arg= FALSE) :Item_ref(view_arg, item, field_name_arg, alias_name_used_arg) {} void save_val(Field *to); double val_real(); longlong val_int(); String *val_str(String* tmp); my_decimal *val_decimal(my_decimal *); bool val_bool(); bool is_null(); bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate); virtual Ref_Type ref_type() { return DIRECT_REF; } }; /** This class is the same as Item_direct_ref but created to wrap Item_ident before fix_fields() call */ class Item_direct_ref_to_ident :public Item_direct_ref { Item_ident *ident; public: Item_direct_ref_to_ident(Item_ident *item) :Item_direct_ref(item->context, (Item**)&item, item->table_name, item->field_name, FALSE) { ident= item; ref= (Item**)&ident; } bool fix_fields(THD *thd, Item **it) { DBUG_ASSERT(ident->type() == FIELD_ITEM || ident->type() == REF_ITEM); if ((!ident->fixed && ident->fix_fields(thd, ref)) || ident->check_cols(1)) return TRUE; set_properties(); return FALSE; } virtual void print(String *str, enum_query_type query_type) { ident->print(str, query_type); } }; class Item_cache; class Expression_cache; /** The objects of this class can store its values in an expression cache. */ class Item_cache_wrapper :public Item_result_field { private: /* Pointer on the cached expression */ Item *orig_item; Expression_cache *expr_cache; /* In order to put the expression into the expression cache and return value of val_*() method, we will need to get the expression value twice (probably in different types). In order to avoid making two (potentially costly) orig_item->val_*() calls, we store expression value in this Item_cache object. */ Item_cache *expr_value; List parameters; Item *check_cache(); void cache(); void init_on_demand(); public: Item_cache_wrapper(Item *item_arg); ~Item_cache_wrapper(); const char *func_name() const { return ""; } enum Type type() const { return EXPR_CACHE_ITEM; } enum Type real_type() const { return orig_item->type(); } bool set_cache(THD *thd); bool fix_fields(THD *thd, Item **it); void fix_length_and_dec() {} void cleanup(); /* Methods of getting value which should be cached in the cache */ void save_val(Field *to); double val_real(); longlong val_int(); String *val_str(String* tmp); my_decimal *val_decimal(my_decimal *); bool val_bool(); bool is_null(); bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate); bool send(Protocol *protocol, String *buffer); void save_org_in_field(Field *field) { save_val(field); } void save_in_result_field(bool no_conversions) { save_val(result_field); } Item* get_tmp_table_item(THD *thd_arg); /* Following methods make this item transparent as much as possible */ virtual void print(String *str, enum_query_type query_type); virtual const char *full_name() const { return orig_item->full_name(); } virtual void make_field(Send_field *field) { orig_item->make_field(field); } bool eq(const Item *item, bool binary_cmp) const { Item *it= ((Item *) item)->real_item(); return orig_item->eq(it, binary_cmp); } void fix_after_pullout(st_select_lex *new_parent, Item **refptr) { orig_item->fix_after_pullout(new_parent, &orig_item); } int save_in_field(Field *to, bool no_conversions); enum Item_result result_type () const { return orig_item->result_type(); } enum_field_types field_type() const { return orig_item->field_type(); } table_map used_tables() const { return orig_item->used_tables(); } void update_used_tables() { orig_item->update_used_tables(); } bool const_item() const { return orig_item->const_item(); } table_map not_null_tables() const { return orig_item->not_null_tables(); } bool walk(Item_processor processor, bool walk_subquery, uchar *arg) { return orig_item->walk(processor, walk_subquery, arg) || (this->*processor)(arg); } bool enumerate_field_refs_processor(uchar *arg) { return orig_item->enumerate_field_refs_processor(arg); } Item_field *filed_for_view_update() { return orig_item->filed_for_view_update(); } /* Row emulation: forwarding of ROW-related calls to orig_item */ uint cols() { return result_type() == ROW_RESULT ? orig_item->cols() : 1; } Item* element_index(uint i) { return result_type() == ROW_RESULT ? orig_item->element_index(i) : this; } Item** addr(uint i) { return result_type() == ROW_RESULT ? orig_item->addr(i) : 0; } bool check_cols(uint c) { return (result_type() == ROW_RESULT ? orig_item->check_cols(c) : Item::check_cols(c)); } bool null_inside() { return result_type() == ROW_RESULT ? orig_item->null_inside() : 0; } void bring_value() { if (result_type() == ROW_RESULT) orig_item->bring_value(); } virtual bool is_expensive() { return orig_item->is_expensive(); } bool is_expensive_processor(uchar *arg) { return orig_item->is_expensive_processor(arg); } bool check_vcol_func_processor(uchar *arg) { return trace_unsupported_by_check_vcol_func_processor("cache"); } }; /* Class for view fields, the same as Item_direct_ref, but call fix_fields of reference if it is not called yet */ class Item_direct_view_ref :public Item_direct_ref { Item_equal *item_equal; TABLE_LIST *view; public: Item_direct_view_ref(Name_resolution_context *context_arg, Item **item, const char *table_name_arg, const char *field_name_arg, TABLE_LIST *view_arg) :Item_direct_ref(context_arg, item, table_name_arg, field_name_arg), item_equal(0), view(view_arg) {} /* Constructor need to process subselect with temporary tables (see Item) */ Item_direct_view_ref(THD *thd, Item_direct_ref *item) :Item_direct_ref(thd, item), item_equal(0) {} Item_direct_view_ref(TABLE_LIST *view_arg, Item **item, const char *field_name_arg) :Item_direct_ref(view_arg, item, field_name_arg), item_equal(0) {} bool fix_fields(THD *, Item **); bool eq(const Item *item, bool binary_cmp) const; Item *get_tmp_table_item(THD *thd) { Item *item= Item_ref::get_tmp_table_item(thd); item->name= name; return item; } virtual Ref_Type ref_type() { return VIEW_REF; } Item_equal *get_item_equal() { return item_equal; } void set_item_equal(Item_equal *item_eq) { item_equal= item_eq; } Item_equal *find_item_equal(COND_EQUAL *cond_equal); bool subst_argument_checker(uchar **arg); Item *equal_fields_propagator(uchar *arg); Item *replace_equal_field(uchar *arg); table_map used_tables() const; table_map not_null_tables() const; bool walk(Item_processor processor, bool walk_subquery, uchar *arg) { return (*ref)->walk(processor, walk_subquery, arg) || (this->*processor)(arg); } bool view_used_tables_processor(uchar *arg) { TABLE_LIST *view_arg= (TABLE_LIST *) arg; if (view_arg == view) view_arg->view_used_tables|= (*ref)->used_tables(); return 0; } }; /* Class for outer fields. An object of this class is created when the select where the outer field was resolved is a grouping one. After it has been fixed the ref field will point to either an Item_ref or an Item_direct_ref object which will be used to access the field. See also comments for the fix_inner_refs() and the Item_field::fix_outer_field() functions. */ class Item_sum; class Item_outer_ref :public Item_direct_ref { public: Item *outer_ref; /* The aggregate function under which this outer ref is used, if any. */ Item_sum *in_sum_func; /* TRUE <=> that the outer_ref is already present in the select list of the outer select. */ bool found_in_select_list; bool found_in_group_by; Item_outer_ref(Name_resolution_context *context_arg, Item_field *outer_field_arg) :Item_direct_ref(context_arg, 0, outer_field_arg->table_name, outer_field_arg->field_name), outer_ref(outer_field_arg), in_sum_func(0), found_in_select_list(0), found_in_group_by(0) { ref= &outer_ref; set_properties(); fixed= 0; } Item_outer_ref(Name_resolution_context *context_arg, Item **item, const char *table_name_arg, const char *field_name_arg, bool alias_name_used_arg) :Item_direct_ref(context_arg, item, table_name_arg, field_name_arg, alias_name_used_arg), outer_ref(0), in_sum_func(0), found_in_select_list(1), found_in_group_by(0) {} void save_in_result_field(bool no_conversions) { outer_ref->save_org_in_field(result_field); } bool fix_fields(THD *, Item **); void fix_after_pullout(st_select_lex *new_parent, Item **ref); table_map used_tables() const { return (*ref)->const_item() ? 0 : OUTER_REF_TABLE_BIT; } table_map not_null_tables() const { return 0; } virtual Ref_Type ref_type() { return OUTER_REF; } bool check_inner_refs_processor(uchar * arg); }; class Item_in_subselect; /* An object of this class: - Converts val_XXX() calls to ref->val_XXX_result() calls, like Item_ref. - Sets owner->was_null=TRUE if it has returned a NULL value from any val_XXX() function. This allows to inject an Item_ref_null_helper object into subquery and then check if the subquery has produced a row with NULL value. */ class Item_ref_null_helper: public Item_ref { protected: Item_in_subselect* owner; public: Item_ref_null_helper(Name_resolution_context *context_arg, Item_in_subselect* master, Item **item, const char *table_name_arg, const char *field_name_arg) :Item_ref(context_arg, item, table_name_arg, field_name_arg), owner(master) {} void save_val(Field *to); double val_real(); longlong val_int(); String* val_str(String* s); my_decimal *val_decimal(my_decimal *); bool val_bool(); bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate); virtual void print(String *str, enum_query_type query_type); table_map used_tables() const; }; /* The following class is used to optimize comparing of date and bigint columns We need to save the original item ('ref') to be able to call ref->save_in_field(). This is used to create index search keys. An instance of Item_int_with_ref may have signed or unsigned integer value. */ class Item_int_with_ref :public Item_int { Item *ref; public: Item_int_with_ref(longlong i, Item *ref_arg, bool unsigned_arg) : Item_int(i), ref(ref_arg) { unsigned_flag= unsigned_arg; } int save_in_field(Field *field, bool no_conversions) { return ref->save_in_field(field, no_conversions); } Item *clone_item(); virtual Item *real_item() { return ref; } }; #ifdef MYSQL_SERVER #include "gstream.h" #include "spatial.h" #include "item_sum.h" #include "item_func.h" #include "item_row.h" #include "item_cmpfunc.h" #include "item_strfunc.h" #include "item_geofunc.h" #include "item_timefunc.h" #include "item_subselect.h" #include "item_xmlfunc.h" #include "item_create.h" #endif /** Base class to implement typed value caching Item classes Item_copy_ classes are very similar to the corresponding Item_ classes (e.g. Item_copy_int is similar to Item_int) but they add the following additional functionality to Item_ : 1. Nullability 2. Possibility to store the value not only on instantiation time, but also later. Item_copy_ classes are a functionality subset of Item_cache_ classes, as e.g. they don't support comparisons with the original Item as Item_cache_ classes do. Item_copy_ classes are used in GROUP BY calculation. TODO: Item_copy should be made an abstract interface and Item_copy_ classes should inherit both the respective Item_ class and the interface. Ideally we should drop Item_copy_ classes altogether and merge their functionality to Item_cache_ (and these should be made to inherit from Item_). */ class Item_copy :public Item { protected: /** Stores the type of the resulting field that would be used to store the data in the cache. This is to avoid calls to the original item. */ enum enum_field_types cached_field_type; /** The original item that is copied */ Item *item; /** Stores the result type of the original item, so it can be returned without calling the original item's method */ Item_result cached_result_type; /** Constructor of the Item_copy class stores metadata information about the original class as well as a pointer to it. */ Item_copy(Item *i) { item= i; null_value=maybe_null=item->maybe_null; decimals=item->decimals; max_length=item->max_length; name=item->name; cached_field_type= item->field_type(); cached_result_type= item->result_type(); unsigned_flag= item->unsigned_flag; fixed= item->fixed; collation.set(item->collation); } public: /** Factory method to create the appropriate subclass dependent on the type of the original item. @param item the original item. */ static Item_copy *create (Item *item); /** Update the cache with the value of the original item This is the method that updates the cached value. It must be explicitly called by the user of this class to store the value of the orginal item in the cache. */ virtual void copy() = 0; Item *get_item() { return item; } /** All of the subclasses should have the same type tag */ enum Type type() const { return COPY_STR_ITEM; } enum_field_types field_type() const { return cached_field_type; } enum Item_result result_type () const { return cached_result_type; } void make_field(Send_field *field) { item->make_field(field); } table_map used_tables() const { return (table_map) 1L; } bool const_item() const { return 0; } bool is_null() { return null_value; } bool check_vcol_func_processor(uchar *arg) { return trace_unsupported_by_check_vcol_func_processor("copy"); } /* Override the methods below as pure virtual to make sure all the sub-classes implement them. */ virtual String *val_str(String*) = 0; virtual my_decimal *val_decimal(my_decimal *) = 0; virtual double val_real() = 0; virtual longlong val_int() = 0; virtual int save_in_field(Field *field, bool no_conversions) = 0; }; /** Implementation of a string cache. Uses Item::str_value for storage */ class Item_copy_string : public Item_copy { public: Item_copy_string (Item *item) : Item_copy(item) {} String *val_str(String*); my_decimal *val_decimal(my_decimal *); double val_real(); longlong val_int(); void copy(); int save_in_field(Field *field, bool no_conversions); }; class Item_copy_int : public Item_copy { protected: longlong cached_value; public: Item_copy_int (Item *i) : Item_copy(i) {} int save_in_field(Field *field, bool no_conversions); virtual String *val_str(String*); virtual my_decimal *val_decimal(my_decimal *); virtual double val_real() { return null_value ? 0.0 : (double) cached_value; } virtual longlong val_int() { return null_value ? LL(0) : cached_value; } virtual void copy(); }; class Item_copy_uint : public Item_copy_int { public: Item_copy_uint (Item *item) : Item_copy_int(item) { unsigned_flag= 1; } String *val_str(String*); double val_real() { return null_value ? 0.0 : (double) (ulonglong) cached_value; } }; class Item_copy_float : public Item_copy { protected: double cached_value; public: Item_copy_float (Item *i) : Item_copy(i) {} int save_in_field(Field *field, bool no_conversions); String *val_str(String*); my_decimal *val_decimal(my_decimal *); double val_real() { return null_value ? 0.0 : cached_value; } longlong val_int() { return (longlong) rint(val_real()); } void copy() { cached_value= item->val_real(); null_value= item->null_value; } }; class Item_copy_decimal : public Item_copy { protected: my_decimal cached_value; public: Item_copy_decimal (Item *i) : Item_copy(i) {} int save_in_field(Field *field, bool no_conversions); String *val_str(String*); my_decimal *val_decimal(my_decimal *) { return null_value ? NULL: &cached_value; } double val_real(); longlong val_int(); void copy(); }; /* Cached_item_XXX objects are not exactly caches. They do the following: Each Cached_item_XXX object has - its source item - saved value of the source item - cmp() method that compares the saved value with the current value of the source item, and if they were not equal saves item's value into the saved value. */ /* Cached_item_XXX objects are not exactly caches. They do the following: Each Cached_item_XXX object has - its source item - saved value of the source item - cmp() method that compares the saved value with the current value of the source item, and if they were not equal saves item's value into the saved value. */ class Cached_item :public Sql_alloc { public: bool null_value; Cached_item() :null_value(0) {} virtual bool cmp(void)=0; virtual ~Cached_item(); /*line -e1509 */ }; class Cached_item_str :public Cached_item { Item *item; uint32 value_max_length; String value,tmp_value; public: Cached_item_str(THD *thd, Item *arg); bool cmp(void); ~Cached_item_str(); // Deallocate String:s }; class Cached_item_real :public Cached_item { Item *item; double value; public: Cached_item_real(Item *item_par) :item(item_par),value(0.0) {} bool cmp(void); }; class Cached_item_int :public Cached_item { Item *item; longlong value; public: Cached_item_int(Item *item_par) :item(item_par),value(0) {} bool cmp(void); }; class Cached_item_decimal :public Cached_item { Item *item; my_decimal value; public: Cached_item_decimal(Item *item_par); bool cmp(void); }; class Cached_item_field :public Cached_item { uchar *buff; Field *field; uint length; public: Cached_item_field(Field *arg_field) : field(arg_field) { field= arg_field; /* TODO: take the memory allocation below out of the constructor. */ buff= (uchar*) sql_calloc(length=field->pack_length()); } bool cmp(void); }; class Item_default_value : public Item_field { public: Item *arg; Item_default_value(Name_resolution_context *context_arg) :Item_field(context_arg, (const char *)NULL, (const char *)NULL, (const char *)NULL), arg(NULL) {} Item_default_value(Name_resolution_context *context_arg, Item *a) :Item_field(context_arg, (const char *)NULL, (const char *)NULL, (const char *)NULL), arg(a) {} enum Type type() const { return DEFAULT_VALUE_ITEM; } bool eq(const Item *item, bool binary_cmp) const; bool fix_fields(THD *, Item **); virtual void print(String *str, enum_query_type query_type); int save_in_field(Field *field_arg, bool no_conversions); table_map used_tables() const { return (table_map)0L; } bool walk(Item_processor processor, bool walk_subquery, uchar *args) { return arg->walk(processor, walk_subquery, args) || (this->*processor)(args); } Item *transform(Item_transformer transformer, uchar *args); }; /* Item_insert_value -- an implementation of VALUES() function. You can use the VALUES(col_name) function in the UPDATE clause to refer to column values from the INSERT portion of the INSERT ... UPDATE statement. In other words, VALUES(col_name) in the UPDATE clause refers to the value of col_name that would be inserted, had no duplicate-key conflict occurred. In all other places this function returns NULL. */ class Item_insert_value : public Item_field { public: Item *arg; Item_insert_value(Name_resolution_context *context_arg, Item *a) :Item_field(context_arg, (const char *)NULL, (const char *)NULL, (const char *)NULL), arg(a) {} bool eq(const Item *item, bool binary_cmp) const; bool fix_fields(THD *, Item **); virtual void print(String *str, enum_query_type query_type); int save_in_field(Field *field_arg, bool no_conversions) { return Item_field::save_in_field(field_arg, no_conversions); } enum Type type() const { return INSERT_VALUE_ITEM; } /* We use RAND_TABLE_BIT to prevent Item_insert_value from being treated as a constant and precalculated before execution */ table_map used_tables() const { return RAND_TABLE_BIT; } bool walk(Item_processor processor, bool walk_subquery, uchar *args) { return arg->walk(processor, walk_subquery, args) || (this->*processor)(args); } bool check_vcol_func_processor(uchar *arg) { return trace_unsupported_by_check_vcol_func_processor("values"); } }; class Table_triggers_list; /* Represents NEW/OLD version of field of row which is changed/read in trigger. Note: For this item main part of actual binding to Field object happens not during fix_fields() call (like for Item_field) but right after parsing of trigger definition, when table is opened, with special setup_field() call. On fix_fields() stage we simply choose one of two Field instances representing either OLD or NEW version of this field. */ class Item_trigger_field : public Item_field, private Settable_routine_parameter { public: /* Is this item represents row from NEW or OLD row ? */ enum row_version_type {OLD_ROW, NEW_ROW}; row_version_type row_version; /* Next in list of all Item_trigger_field's in trigger */ Item_trigger_field *next_trg_field; /* Index of the field in the TABLE::field array */ uint field_idx; /* Pointer to Table_trigger_list object for table of this trigger */ Table_triggers_list *triggers; Item_trigger_field(Name_resolution_context *context_arg, row_version_type row_ver_arg, const char *field_name_arg, ulong priv, const bool ro) :Item_field(context_arg, (const char *)NULL, (const char *)NULL, field_name_arg), row_version(row_ver_arg), field_idx((uint)-1), original_privilege(priv), want_privilege(priv), table_grants(NULL), read_only (ro) {} void setup_field(THD *thd, TABLE *table, GRANT_INFO *table_grant_info); enum Type type() const { return TRIGGER_FIELD_ITEM; } bool eq(const Item *item, bool binary_cmp) const; bool fix_fields(THD *, Item **); virtual void print(String *str, enum_query_type query_type); table_map used_tables() const { return (table_map)0L; } Field *get_tmp_table_field() { return 0; } Item *copy_or_same(THD *thd) { return this; } Item *get_tmp_table_item(THD *thd) { return copy_or_same(thd); } void cleanup(); private: void set_required_privilege(bool rw); bool set_value(THD *thd, sp_rcontext *ctx, Item **it); public: Settable_routine_parameter *get_settable_routine_parameter() { return (read_only ? 0 : this); } bool set_value(THD *thd, Item **it) { return set_value(thd, NULL, it); } private: /* 'want_privilege' holds privileges required to perform operation on this trigger field (SELECT_ACL if we are going to read it and UPDATE_ACL if we are going to update it). It is initialized at parse time but can be updated later if this trigger field is used as OUT or INOUT parameter of stored routine (in this case set_required_privilege() is called to appropriately update want_privilege and cleanup() is responsible for restoring of original want_privilege once parameter's value is updated). */ ulong original_privilege; ulong want_privilege; GRANT_INFO *table_grants; /* Trigger field is read-only unless it belongs to the NEW row in a BEFORE INSERT of BEFORE UPDATE trigger. */ bool read_only; virtual bool check_vcol_func_processor(uchar *arg) { return trace_unsupported_by_check_vcol_func_processor("trigger"); } }; /** @todo Implement the is_null() method for this class. Currently calling is_null() on any Item_cache object resolves to Item::is_null(), which reutns FALSE for any value. */ class Item_cache: public Item_basic_constant { protected: Item *example; table_map used_table_map; /** Field that this object will get value from. This is used by index-based subquery engines to detect and remove the equality injected by IN->EXISTS transformation. */ Field *cached_field; enum enum_field_types cached_field_type; /* TRUE <=> cache holds value of the last stored item (i.e actual value). store() stores item to be cached and sets this flag to FALSE. On the first call of val_xxx function if this flag is set to FALSE the cache_value() will be called to actually cache value of saved item. cache_value() will set this flag to TRUE. */ bool value_cached; public: Item_cache(): example(0), used_table_map(0), cached_field(0), cached_field_type(MYSQL_TYPE_STRING), value_cached(0) { fixed= 1; maybe_null= 1; null_value= 1; } Item_cache(enum_field_types field_type_arg): example(0), used_table_map(0), cached_field(0), cached_field_type(field_type_arg), value_cached(0) { fixed= 1; maybe_null= 1; null_value= 1; } void set_used_tables(table_map map) { used_table_map= map; } virtual bool allocate(uint i) { return 0; } virtual bool setup(Item *item) { example= item; max_length= item->max_length; decimals= item->decimals; collation.set(item->collation); unsigned_flag= item->unsigned_flag; if (item->type() == FIELD_ITEM) cached_field= ((Item_field *)item)->field; return 0; }; enum Type type() const { return CACHE_ITEM; } enum_field_types field_type() const { return cached_field_type; } static Item_cache* get_cache(const Item *item); static Item_cache* get_cache(const Item* item, const Item_result type); table_map used_tables() const { return used_table_map; } virtual void keep_array() {} virtual void print(String *str, enum_query_type query_type); bool eq_def(Field *field) { return cached_field ? cached_field->eq_def (field) : FALSE; } bool eq(const Item *item, bool binary_cmp) const { return this == item; } bool check_vcol_func_processor(uchar *arg) { return trace_unsupported_by_check_vcol_func_processor("cache"); } /** Check if saved item has a non-NULL value. Will cache value of saved item if not already done. @return TRUE if cached value is non-NULL. */ bool has_value() { return (value_cached || cache_value()) && !null_value; } virtual void store(Item *item); virtual bool cache_value()= 0; bool basic_const_item() const { return test(example && example->basic_const_item());} virtual void clear() { null_value= TRUE; value_cached= FALSE; } bool is_null() { return null_value; } virtual bool is_expensive() { DBUG_ASSERT(example); if (value_cached) return false; return example->is_expensive(); } bool is_expensive_processor(uchar *arg) { DBUG_ASSERT(example); if (value_cached) return false; return example->is_expensive_processor(arg); } }; class Item_cache_int: public Item_cache { protected: longlong value; public: Item_cache_int(): Item_cache(MYSQL_TYPE_LONGLONG), value(0) {} Item_cache_int(enum_field_types field_type_arg): Item_cache(field_type_arg), value(0) {} double val_real(); longlong val_int(); String* val_str(String *str); my_decimal *val_decimal(my_decimal *); enum Item_result result_type() const { return INT_RESULT; } bool cache_value(); int save_in_field(Field *field, bool no_conversions); }; class Item_cache_temporal: public Item_cache_int { public: Item_cache_temporal(enum_field_types field_type_arg); String* val_str(String *str); bool cache_value(); bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate); int save_in_field(Field *field, bool no_conversions); void store_packed(longlong val_arg); /* Having a clone_item method tells optimizer that this object is a constant and need not be optimized further. Important when storing packed datetime values. */ Item *clone_item() { Item_cache_temporal *item= new Item_cache_temporal(cached_field_type); item->store_packed(value); return item; } }; class Item_cache_real: public Item_cache { double value; public: Item_cache_real(): Item_cache(MYSQL_TYPE_DOUBLE), value(0) {} double val_real(); longlong val_int(); String* val_str(String *str); my_decimal *val_decimal(my_decimal *); enum Item_result result_type() const { return REAL_RESULT; } bool cache_value(); }; class Item_cache_decimal: public Item_cache { protected: my_decimal decimal_value; public: Item_cache_decimal(): Item_cache(MYSQL_TYPE_NEWDECIMAL) {} double val_real(); longlong val_int(); String* val_str(String *str); my_decimal *val_decimal(my_decimal *); enum Item_result result_type() const { return DECIMAL_RESULT; } bool cache_value(); }; class Item_cache_str: public Item_cache { char buffer[STRING_BUFFER_USUAL_SIZE]; String *value, value_buff; bool is_varbinary; public: Item_cache_str(const Item *item) : Item_cache(item->field_type()), value(0), is_varbinary(item->type() == FIELD_ITEM && cached_field_type == MYSQL_TYPE_VARCHAR && !((const Item_field *) item)->field->has_charset()) { collation.set(const_cast(item->collation)); } double val_real(); longlong val_int(); String* val_str(String *); my_decimal *val_decimal(my_decimal *); enum Item_result result_type() const { return STRING_RESULT; } CHARSET_INFO *charset() const { return value->charset(); }; int save_in_field(Field *field, bool no_conversions); bool cache_value(); }; class Item_cache_row: public Item_cache { Item_cache **values; uint item_count; bool save_array; public: Item_cache_row() :Item_cache(), values(0), item_count(2), save_array(0) {} /* 'allocate' used only in row transformer, to preallocate space for row cache. */ bool allocate(uint num); /* 'setup' is needed only by row => it not called by simple row subselect (only by IN subselect (in subselect optimizer)) */ bool setup(Item *item); void store(Item *item); void illegal_method_call(const char *); void make_field(Send_field *) { illegal_method_call((const char*)"make_field"); }; double val_real() { illegal_method_call((const char*)"val"); return 0; }; longlong val_int() { illegal_method_call((const char*)"val_int"); return 0; }; String *val_str(String *) { illegal_method_call((const char*)"val_str"); return 0; }; my_decimal *val_decimal(my_decimal *val) { illegal_method_call((const char*)"val_decimal"); return 0; }; enum Item_result result_type() const { return ROW_RESULT; } uint cols() { return item_count; } Item *element_index(uint i) { return values[i]; } Item **addr(uint i) { return (Item **) (values + i); } bool check_cols(uint c); bool null_inside(); void bring_value(); void keep_array() { save_array= 1; } void cleanup() { DBUG_ENTER("Item_cache_row::cleanup"); Item_cache::cleanup(); if (save_array) bzero(values, item_count*sizeof(Item**)); else values= 0; DBUG_VOID_RETURN; } bool cache_value(); }; /* Item_type_holder used to store type. name, length of Item for UNIONS & derived tables. Item_type_holder do not need cleanup() because its time of live limited by single SP/PS execution. */ class Item_type_holder: public Item { protected: TYPELIB *enum_set_typelib; enum_field_types fld_type; Field::geometry_type geometry_type; void get_full_info(Item *item); /* It is used to count decimal precision in join_types */ int prev_decimal_int_part; public: Item_type_holder(THD*, Item*); Item_result result_type() const; enum_field_types field_type() const { return fld_type; }; enum Type type() const { return TYPE_HOLDER; } double val_real(); longlong val_int(); my_decimal *val_decimal(my_decimal *); String *val_str(String*); bool join_types(THD *thd, Item *); Field *make_field_by_type(TABLE *table); static uint32 display_length(Item *item); static enum_field_types get_real_type(Item *); Field::geometry_type get_geometry_type() const { return geometry_type; }; }; class st_select_lex; void mark_select_range_as_dependent(THD *thd, st_select_lex *last_select, st_select_lex *current_sel, Field *found_field, Item *found_item, Item_ident *resolved_item); extern Cached_item *new_Cached_item(THD *thd, Item *item, bool pass_through_ref); extern Item_result item_cmp_type(Item_result a,Item_result b); extern void resolve_const_item(THD *thd, Item **ref, Item *cmp_item); extern int stored_field_cmp_to_item(THD *thd, Field *field, Item *item); extern const String my_null_string; /** Interface for Item iterator */ class Item_iterator { public: /** Shall set this iterator to the position before the first item @note This method also may perform some other initialization actions like allocation of certain resources. */ virtual void open()= 0; /** Shall return the next Item (or NULL if there is no next item) and move pointer to position after it. */ virtual Item *next()= 0; /** Shall force iterator to free resources (if it holds them) @note One should not use the iterator without open() call after close() */ virtual void close()= 0; virtual ~Item_iterator() {} }; /** Item iterator over List_iterator_fast for Item references */ class Item_iterator_ref_list: public Item_iterator { List_iterator list; public: Item_iterator_ref_list(List_iterator &arg_list): list(arg_list) {} void open() { list.rewind(); } Item *next() { return *(list++); } void close() {} }; /** Item iterator over List_iterator_fast for Items */ class Item_iterator_list: public Item_iterator { List_iterator list; public: Item_iterator_list(List_iterator &arg_list): list(arg_list) {} void open() { list.rewind(); } Item *next() { return (list++); } void close() {} }; /** Item iterator over Item interface for rows */ class Item_iterator_row: public Item_iterator { Item *base_item; uint current; public: Item_iterator_row(Item *base) : base_item(base), current(0) {} void open() { current= 0; } Item *next() { if (current >= base_item->cols()) return NULL; return base_item->element_index(current++); } void close() {} }; #endif /* SQL_ITEM_INCLUDED */