diff options
Diffstat (limited to 'sql/item.h')
| -rw-r--r-- | sql/item.h | 70 |
1 files changed, 42 insertions, 28 deletions
diff --git a/sql/item.h b/sql/item.h index f8d04b6c851..b39a95d796c 100644 --- a/sql/item.h +++ b/sql/item.h @@ -99,7 +99,8 @@ public: static void *operator new(size_t size) {return (void*) sql_alloc((uint) size); } static void *operator new(size_t size, MEM_ROOT *mem_root) { return (void*) alloc_root(mem_root, (uint) size); } - static void operator delete(void *ptr,size_t size) {} /*lint -e715 */ + static void operator delete(void *ptr,size_t size) {} + static void operator delete(void *ptr,size_t size, MEM_ROOT *mem_root) {} enum Type {FIELD_ITEM, FUNC_ITEM, SUM_FUNC_ITEM, STRING_ITEM, INT_ITEM, REAL_ITEM, NULL_ITEM, VARBIN_ITEM, @@ -219,7 +220,8 @@ public: a constant expression */ virtual bool basic_const_item() const { return 0; } - virtual Item *new_item() { return 0; } /* Only for const items */ + /* cloning of constant items (0 if it is not const) */ + virtual Item *new_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;} @@ -237,17 +239,29 @@ public: virtual void print(String *str_arg) { str_arg->append(full_name()); } void print_item_w_name(String *); virtual void update_used_tables() {} - virtual void split_sum_func(Item **ref_pointer_array, List<Item> &fields) {} + virtual void split_sum_func(THD *thd, Item **ref_pointer_array, + List<Item> &fields) {} virtual bool get_date(TIME *ltime,uint fuzzydate); virtual bool get_time(TIME *ltime); virtual bool get_date_result(TIME *ltime,uint fuzzydate) { return get_date(ltime,fuzzydate); } virtual bool is_null() { return 0; } + /* + it is "top level" item of WHERE clause and we do not need correct NULL + handling + */ virtual void top_level_item() {} + /* + set field of temporary table for Item which can be switched on temporary + table during query processing (groupping 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 aggegate function in case of no rows for groupping were found + */ virtual void no_rows_in_result() {} virtual Item *copy_or_same(THD *thd) { return this; } virtual Item *copy_andor_structure(THD *thd) { return this; } @@ -407,6 +421,7 @@ public: 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 @@ -416,7 +431,6 @@ class Item_ident :public Item const char *orig_db_name; const char *orig_table_name; const char *orig_field_name; - Item **changed_during_fix_field; public: const char *db_name; const char *table_name; @@ -439,8 +453,6 @@ public: Item_ident(THD *thd, Item_ident *item); const char *full_name() const; void cleanup(); - void register_item_tree_changing(Item **ref) - { changed_during_fix_field= ref; } bool remove_dependence_processor(byte * arg); void print(String *str); @@ -474,13 +486,21 @@ public: field(0), result_field(0), item_equal(0), no_const_subst(0), have_privileges(0), any_privileges(0) { collation.set(DERIVATION_IMPLICIT); } - // Constructor need to process subselect with temporary tables (see Item) + /* + 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 and table - names will live as long as Item_field (important in prep. stmt.) + 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, 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; @@ -491,6 +511,7 @@ public: longlong val_int_result(); String *str_result(String* tmp); bool send(Protocol *protocol, String *str_arg); + void reset_field(Field *f); bool fix_fields(THD *, struct st_table_list *, Item **); void make_field(Send_field *tmp_field); int save_in_field(Field *field,bool no_conversions); @@ -873,8 +894,8 @@ public: class Item_empty_string :public Item_string { public: - Item_empty_string(const char *header,uint length) :Item_string("",0, - &my_charset_bin) + Item_empty_string(const char *header,uint length, CHARSET_INFO *cs= NULL) : + Item_string("",0, cs ? cs : &my_charset_bin) { name=(char*) header; max_length=length;} void make_field(Send_field *field); }; @@ -931,6 +952,7 @@ public: { save_in_field(result_field, no_conversions); } + void cleanup(); }; @@ -939,20 +961,13 @@ class Item_ref :public Item_ident public: Field *result_field; /* Save result here */ Item **ref; - Item **hook_ptr; /* These two to restore */ - Item *orig_item; /* things in 'cleanup()' */ - Item_ref(Item **hook, Item *original,const char *db_par, - const char *table_name_par, const char *field_name_par) - :Item_ident(db_par, table_name_par, field_name_par), result_field(0), - ref(0), hook_ptr(hook), orig_item(original) {} - Item_ref(Item **item, Item **hook, - const char *table_name_par, const char *field_name_par) - :Item_ident(NullS, table_name_par, field_name_par), result_field(0), - ref(item), hook_ptr(hook), orig_item(hook ? *hook:0) {} - // Constructor need to process subselect with temporary tables (see Item) - Item_ref(THD *thd, Item_ref *item, Item **hook) - :Item_ident(thd, item), result_field(item->result_field), ref(item->ref), - hook_ptr(hook), orig_item(hook ? *hook : 0) {} + Item_ref(const char *db_par, const char *table_name_par, + const char *field_name_par) + :Item_ident(db_par, table_name_par, field_name_par), result_field(0), ref(0) {} + Item_ref(Item **item, const char *table_name_par, const char *field_name_par) + :Item_ident(NullS, table_name_par, field_name_par), result_field(0), ref(item) {} + /* 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; } bool eq(const Item *item, bool binary_cmp) const { return ref && (*ref)->eq(item, binary_cmp); } @@ -1009,7 +1024,6 @@ public: bool walk(Item_processor processor, byte *arg) { return (*ref)->walk(processor, arg); } void print(String *str); - void cleanup(); }; class Item_in_subselect; @@ -1020,7 +1034,7 @@ protected: public: Item_ref_null_helper(Item_in_subselect* master, Item **item, const char *table_name_par, const char *field_name_par): - Item_ref(item, NULL, table_name_par, field_name_par), owner(master) {} + Item_ref(item, table_name_par, field_name_par), owner(master) {} double val(); longlong val_int(); String* val_str(String* s); @@ -1458,5 +1472,5 @@ public: extern Item_buff *new_Item_buff(Item *item); extern Item_result item_cmp_type(Item_result a,Item_result b); -extern Item *resolve_const_item(Item *item,Item *cmp_item); +extern void resolve_const_item(THD *thd, Item **ref, Item *cmp_item); extern bool field_is_equal_to_item(Field *field,Item *item); |