/* Copyright (C) 2000-2006 MySQL 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 */ /* This file defines all compare functions */ #ifdef USE_PRAGMA_IMPLEMENTATION #pragma implementation // gcc: Class implementation #endif #include "mysql_priv.h" #include #include "sql_select.h" static bool convert_constant_item(THD *thd, Field *field, Item **item); static Item_result item_store_type(Item_result a, Item *item, my_bool unsigned_flag) { Item_result b= item->result_type(); if (a == STRING_RESULT || b == STRING_RESULT) return STRING_RESULT; else if (a == REAL_RESULT || b == REAL_RESULT) return REAL_RESULT; else if (a == DECIMAL_RESULT || b == DECIMAL_RESULT || unsigned_flag != item->unsigned_flag) return DECIMAL_RESULT; else return INT_RESULT; } static void agg_result_type(Item_result *type, Item **items, uint nitems) { Item **item, **item_end; my_bool unsigned_flag= 0; *type= STRING_RESULT; /* Skip beginning NULL items */ for (item= items, item_end= item + nitems; item < item_end; item++) { if ((*item)->type() != Item::NULL_ITEM) { *type= (*item)->result_type(); unsigned_flag= (*item)->unsigned_flag; item++; break; } } /* Combine result types. Note: NULL items don't affect the result */ for (; item < item_end; item++) { if ((*item)->type() != Item::NULL_ITEM) *type= item_store_type(*type, *item, unsigned_flag); } } /* Compare row signature of two expressions SYNOPSIS: cmp_row_type() item1 the first expression item2 the second expression DESCRIPTION The function checks that two expressions have compatible row signatures i.e. that the number of columns they return are the same and that if they are both row expressions then each component from the first expression has a row signature compatible with the signature of the corresponding component of the second expression. RETURN VALUES 1 type incompatibility has been detected 0 otherwise */ static int cmp_row_type(Item* item1, Item* item2) { uint n= item1->cols(); if (item2->check_cols(n)) return 1; for (uint i=0; ielement_index(i)->check_cols(item1->element_index(i)->cols()) || (item1->element_index(i)->result_type() == ROW_RESULT && cmp_row_type(item1->element_index(i), item2->element_index(i)))) return 1; } return 0; } /* Aggregates result types from the array of items. SYNOPSIS: agg_cmp_type() thd thread handle type [out] the aggregated type items array of items to aggregate the type from nitems number of items in the array DESCRIPTION This function aggregates result types from the array of items. Found type supposed to be used later for comparison of values of these items. Aggregation itself is performed by the item_cmp_type() function. The function also checks compatibility of row signatures for the submitted items (see the spec for the cmp_row_type function). RETURN VALUES 1 type incompatibility has been detected 0 otherwise */ static int agg_cmp_type(THD *thd, Item_result *type, Item **items, uint nitems) { uint i; type[0]= items[0]->result_type(); for (i= 1 ; i < nitems ; i++) { type[0]= item_cmp_type(type[0], items[i]->result_type()); /* When aggregating types of two row expressions we have to check that they have the same cardinality and that each component of the first row expression has a compatible row signature with the signature of the corresponding component of the second row expression. */ if (type[0] == ROW_RESULT && cmp_row_type(items[0], items[i])) return 1; // error found: invalid usage of rows } return 0; } static void my_coll_agg_error(DTCollation &c1, DTCollation &c2, const char *fname) { my_error(ER_CANT_AGGREGATE_2COLLATIONS, MYF(0), c1.collation->name,c1.derivation_name(), c2.collation->name,c2.derivation_name(), fname); } Item_bool_func2* Eq_creator::create(Item *a, Item *b) const { return new Item_func_eq(a, b); } Item_bool_func2* Ne_creator::create(Item *a, Item *b) const { return new Item_func_ne(a, b); } Item_bool_func2* Gt_creator::create(Item *a, Item *b) const { return new Item_func_gt(a, b); } Item_bool_func2* Lt_creator::create(Item *a, Item *b) const { return new Item_func_lt(a, b); } Item_bool_func2* Ge_creator::create(Item *a, Item *b) const { return new Item_func_ge(a, b); } Item_bool_func2* Le_creator::create(Item *a, Item *b) const { return new Item_func_le(a, b); } /* Test functions Most of these returns 0LL if false and 1LL if true and NULL if some arg is NULL. */ longlong Item_func_not::val_int() { DBUG_ASSERT(fixed == 1); bool value= args[0]->val_bool(); null_value=args[0]->null_value; return ((!null_value && value == 0) ? 1 : 0); } /* We put any NOT expression into parenthesis to avoid possible problems with internal view representations where any '!' is converted to NOT. It may cause a problem if '!' is used in an expression together with other operators whose precedence is lower than the precedence of '!' yet higher than the precedence of NOT. */ void Item_func_not::print(String *str) { str->append('('); Item_func::print(str); str->append(')'); } /* special NOT for ALL subquery */ longlong Item_func_not_all::val_int() { DBUG_ASSERT(fixed == 1); bool value= args[0]->val_bool(); /* return TRUE if there was records in underlying select in max/min optimization (ALL subquery) */ if (empty_underlying_subquery()) return 1; null_value= args[0]->null_value; return ((!null_value && value == 0) ? 1 : 0); } bool Item_func_not_all::empty_underlying_subquery() { return ((test_sum_item && !test_sum_item->any_value()) || (test_sub_item && !test_sub_item->any_value())); } void Item_func_not_all::print(String *str) { if (show) Item_func::print(str); else args[0]->print(str); } /* Special NOP (No OPeration) for ALL subquery it is like Item_func_not_all (return TRUE if underlying subquery do not return rows) but if subquery returns some rows it return same value as argument (TRUE/FALSE). */ longlong Item_func_nop_all::val_int() { DBUG_ASSERT(fixed == 1); longlong value= args[0]->val_int(); /* return FALSE if there was records in underlying select in max/min optimization (SAME/ANY subquery) */ if (empty_underlying_subquery()) return 0; null_value= args[0]->null_value; return (null_value || value == 0) ? 0 : 1; } /* Convert a constant item to an int and replace the original item SYNOPSIS convert_constant_item() thd thread handle field item will be converted using the type of this field item [in/out] reference to the item to convert DESCRIPTION The function converts a constant expression or string to an integer. On successful conversion the original item is substituted for the result of the item evaluation. This is done when comparing DATE/TIME of different formats and also when comparing bigint to strings (in which case strings are converted to bigints). NOTES This function is called only at prepare stage. As all derived tables are filled only after all derived tables are prepared we do not evaluate items with subselects here because they can contain derived tables and thus we may attempt to use a table that has not been populated yet. RESULT VALUES 0 Can't convert item 1 Item was replaced with an integer version of the item */ static bool convert_constant_item(THD *thd, Field *field, Item **item) { if (!(*item)->with_subselect && (*item)->const_item()) { /* For comparison purposes allow invalid dates like 2000-01-32 */ ulong orig_sql_mode= thd->variables.sql_mode; thd->variables.sql_mode|= MODE_INVALID_DATES; if (!(*item)->save_in_field(field, 1) && !((*item)->null_value)) { Item *tmp=new Item_int_with_ref(field->val_int(), *item, test(field->flags & UNSIGNED_FLAG)); thd->variables.sql_mode= orig_sql_mode; if (tmp) thd->change_item_tree(item, tmp); return 1; // Item was replaced } thd->variables.sql_mode= orig_sql_mode; } return 0; } void Item_bool_func2::fix_length_and_dec() { max_length= 1; // Function returns 0 or 1 THD *thd; /* As some compare functions are generated after sql_yacc, we have to check for out of memory conditions here */ if (!args[0] || !args[1]) return; /* We allow to convert to Unicode character sets in some cases. The conditions when conversion is possible are: - arguments A and B have different charsets - A wins according to coercibility rules - character set of A is superset for character set of B If all of the above is true, then it's possible to convert B into the character set of A, and then compare according to the collation of A. */ DTCollation coll; if (args[0]->result_type() == STRING_RESULT && args[1]->result_type() == STRING_RESULT && agg_arg_charsets(coll, args, 2, MY_COLL_CMP_CONV, 1)) return; args[0]->cmp_context= args[1]->cmp_context= item_cmp_type(args[0]->result_type(), args[1]->result_type()); // Make a special case of compare with fields to get nicer DATE comparisons if (functype() == LIKE_FUNC) // Disable conversion in case of LIKE function. { set_cmp_func(); return; } thd= current_thd; if (!thd->is_context_analysis_only()) { Item *arg_real_item= args[0]->real_item(); if (arg_real_item->type() == FIELD_ITEM) { Field *field=((Item_field*) arg_real_item)->field; if (field->can_be_compared_as_longlong()) { if (convert_constant_item(thd, field,&args[1])) { cmp.set_cmp_func(this, tmp_arg, tmp_arg+1, INT_RESULT); // Works for all types. args[0]->cmp_context= args[1]->cmp_context= INT_RESULT; return; } } } arg_real_item= args[1]->real_item(); if (arg_real_item->type() == FIELD_ITEM) { Field *field=((Item_field*) arg_real_item)->field; if (field->can_be_compared_as_longlong()) { if (convert_constant_item(thd, field,&args[0])) { cmp.set_cmp_func(this, tmp_arg, tmp_arg+1, INT_RESULT); // Works for all types. args[0]->cmp_context= args[1]->cmp_context= INT_RESULT; return; } } } } set_cmp_func(); } int Arg_comparator::set_compare_func(Item_bool_func2 *item, Item_result type) { owner= item; func= comparator_matrix[type] [test(owner->functype() == Item_func::EQUAL_FUNC)]; switch (type) { case ROW_RESULT: { uint n= (*a)->cols(); if (n != (*b)->cols()) { my_error(ER_OPERAND_COLUMNS, MYF(0), n); comparators= 0; return 1; } if (!(comparators= new Arg_comparator[n])) return 1; for (uint i=0; i < n; i++) { if ((*a)->element_index(i)->cols() != (*b)->element_index(i)->cols()) { my_error(ER_OPERAND_COLUMNS, MYF(0), (*a)->element_index(i)->cols()); return 1; } comparators[i].set_cmp_func(owner, (*a)->addr(i), (*b)->addr(i)); } break; } case STRING_RESULT: { /* We must set cmp_charset here as we may be called from for an automatic generated item, like in natural join */ if (cmp_collation.set((*a)->collation, (*b)->collation) || cmp_collation.derivation == DERIVATION_NONE) { my_coll_agg_error((*a)->collation, (*b)->collation, owner->func_name()); return 1; } if (cmp_collation.collation == &my_charset_bin) { /* We are using BLOB/BINARY/VARBINARY, change to compare byte by byte, without removing end space */ if (func == &Arg_comparator::compare_string) func= &Arg_comparator::compare_binary_string; else if (func == &Arg_comparator::compare_e_string) func= &Arg_comparator::compare_e_binary_string; /* As this is binary compassion, mark all fields that they can't be transformed. Otherwise we would get into trouble with comparisons like: WHERE col= 'j' AND col LIKE BINARY 'j' which would be transformed to: WHERE col= 'j' */ (*a)->walk(&Item::set_no_const_sub, (byte*) 0); (*b)->walk(&Item::set_no_const_sub, (byte*) 0); } break; } case INT_RESULT: { if (func == &Arg_comparator::compare_int_signed) { if ((*a)->unsigned_flag) func= (((*b)->unsigned_flag)? &Arg_comparator::compare_int_unsigned : &Arg_comparator::compare_int_unsigned_signed); else if ((*b)->unsigned_flag) func= &Arg_comparator::compare_int_signed_unsigned; } else if (func== &Arg_comparator::compare_e_int) { if ((*a)->unsigned_flag ^ (*b)->unsigned_flag) func= &Arg_comparator::compare_e_int_diff_signedness; } break; } case DECIMAL_RESULT: break; case REAL_RESULT: { if ((*a)->decimals < NOT_FIXED_DEC && (*b)->decimals < NOT_FIXED_DEC) { precision= 5 * log_01[max((*a)->decimals, (*b)->decimals)]; if (func == &Arg_comparator::compare_real) func= &Arg_comparator::compare_real_fixed; else if (func == &Arg_comparator::compare_e_real) func= &Arg_comparator::compare_e_real_fixed; } break; } default: DBUG_ASSERT(0); } return 0; } int Arg_comparator::compare_string() { String *res1,*res2; if ((res1= (*a)->val_str(&owner->tmp_value1))) { if ((res2= (*b)->val_str(&owner->tmp_value2))) { owner->null_value= 0; return sortcmp(res1,res2,cmp_collation.collation); } } owner->null_value= 1; return -1; } /* Compare strings byte by byte. End spaces are also compared. RETURN < 0 *a < *b 0 *b == *b > 0 *a > *b */ int Arg_comparator::compare_binary_string() { String *res1,*res2; if ((res1= (*a)->val_str(&owner->tmp_value1))) { if ((res2= (*b)->val_str(&owner->tmp_value2))) { owner->null_value= 0; uint res1_length= res1->length(); uint res2_length= res2->length(); int cmp= memcmp(res1->ptr(), res2->ptr(), min(res1_length,res2_length)); return cmp ? cmp : (int) (res1_length - res2_length); } } owner->null_value= 1; return -1; } /* Compare strings, but take into account that NULL == NULL */ int Arg_comparator::compare_e_string() { String *res1,*res2; res1= (*a)->val_str(&owner->tmp_value1); res2= (*b)->val_str(&owner->tmp_value2); if (!res1 || !res2) return test(res1 == res2); return test(sortcmp(res1, res2, cmp_collation.collation) == 0); } int Arg_comparator::compare_e_binary_string() { String *res1,*res2; res1= (*a)->val_str(&owner->tmp_value1); res2= (*b)->val_str(&owner->tmp_value2); if (!res1 || !res2) return test(res1 == res2); return test(stringcmp(res1, res2) == 0); } int Arg_comparator::compare_real() { /* Fix yet another manifestation of Bug#2338. 'Volatile' will instruct gcc to flush double values out of 80-bit Intel FPU registers before performing the comparison. */ volatile double val1, val2; val1= (*a)->val_real(); if (!(*a)->null_value) { val2= (*b)->val_real(); if (!(*b)->null_value) { owner->null_value= 0; if (val1 < val2) return -1; if (val1 == val2) return 0; return 1; } } owner->null_value= 1; return -1; } int Arg_comparator::compare_decimal() { my_decimal value1; my_decimal *val1= (*a)->val_decimal(&value1); if (!(*a)->null_value) { my_decimal value2; my_decimal *val2= (*b)->val_decimal(&value2); if (!(*b)->null_value) { owner->null_value= 0; return my_decimal_cmp(val1, val2); } } owner->null_value= 1; return -1; } int Arg_comparator::compare_e_real() { double val1= (*a)->val_real(); double val2= (*b)->val_real(); if ((*a)->null_value || (*b)->null_value) return test((*a)->null_value && (*b)->null_value); return test(val1 == val2); } int Arg_comparator::compare_e_decimal() { my_decimal value1, value2; my_decimal *val1= (*a)->val_decimal(&value1); my_decimal *val2= (*b)->val_decimal(&value2); if ((*a)->null_value || (*b)->null_value) return test((*a)->null_value && (*b)->null_value); return test(my_decimal_cmp(val1, val2) == 0); } int Arg_comparator::compare_real_fixed() { /* Fix yet another manifestation of Bug#2338. 'Volatile' will instruct gcc to flush double values out of 80-bit Intel FPU registers before performing the comparison. */ volatile double val1, val2; val1= (*a)->val_real(); if (!(*a)->null_value) { val2= (*b)->val_real(); if (!(*b)->null_value) { owner->null_value= 0; if (val1 == val2 || fabs(val1 - val2) < precision) return 0; if (val1 < val2) return -1; return 1; } } owner->null_value= 1; return -1; } int Arg_comparator::compare_e_real_fixed() { double val1= (*a)->val_real(); double val2= (*b)->val_real(); if ((*a)->null_value || (*b)->null_value) return test((*a)->null_value && (*b)->null_value); return test(val1 == val2 || fabs(val1 - val2) < precision); } int Arg_comparator::compare_int_signed() { longlong val1= (*a)->val_int(); if (!(*a)->null_value) { longlong val2= (*b)->val_int(); if (!(*b)->null_value) { owner->null_value= 0; if (val1 < val2) return -1; if (val1 == val2) return 0; return 1; } } owner->null_value= 1; return -1; } /* Compare values as BIGINT UNSIGNED. */ int Arg_comparator::compare_int_unsigned() { ulonglong val1= (*a)->val_int(); if (!(*a)->null_value) { ulonglong val2= (*b)->val_int(); if (!(*b)->null_value) { owner->null_value= 0; if (val1 < val2) return -1; if (val1 == val2) return 0; return 1; } } owner->null_value= 1; return -1; } /* Compare signed (*a) with unsigned (*B) */ int Arg_comparator::compare_int_signed_unsigned() { longlong sval1= (*a)->val_int(); if (!(*a)->null_value) { ulonglong uval2= (ulonglong)(*b)->val_int(); if (!(*b)->null_value) { owner->null_value= 0; if (sval1 < 0 || (ulonglong)sval1 < uval2) return -1; if ((ulonglong)sval1 == uval2) return 0; return 1; } } owner->null_value= 1; return -1; } /* Compare unsigned (*a) with signed (*B) */ int Arg_comparator::compare_int_unsigned_signed() { ulonglong uval1= (ulonglong)(*a)->val_int(); if (!(*a)->null_value) { longlong sval2= (*b)->val_int(); if (!(*b)->null_value) { owner->null_value= 0; if (sval2 < 0) return 1; if (uval1 < (ulonglong)sval2) return -1; if (uval1 == (ulonglong)sval2) return 0; return 1; } } owner->null_value= 1; return -1; } int Arg_comparator::compare_e_int() { longlong val1= (*a)->val_int(); longlong val2= (*b)->val_int(); if ((*a)->null_value || (*b)->null_value) return test((*a)->null_value && (*b)->null_value); return test(val1 == val2); } /* Compare unsigned *a with signed *b or signed *a with unsigned *b. */ int Arg_comparator::compare_e_int_diff_signedness() { longlong val1= (*a)->val_int(); longlong val2= (*b)->val_int(); if ((*a)->null_value || (*b)->null_value) return test((*a)->null_value && (*b)->null_value); return (val1 >= 0) && test(val1 == val2); } int Arg_comparator::compare_row() { int res= 0; bool was_null= 0; (*a)->bring_value(); (*b)->bring_value(); uint n= (*a)->cols(); for (uint i= 0; inull_value) { // NULL was compared if (owner->abort_on_null) return -1; // We do not need correct NULL returning was_null= 1; owner->null_value= 0; res= 0; // continue comparison (maybe we will meet explicit difference) } else if (res) return res; } if (was_null) { /* There was NULL(s) in comparison in some parts, but there was not explicit difference in other parts, so we have to return NULL */ owner->null_value= 1; return -1; } return 0; } int Arg_comparator::compare_e_row() { (*a)->bring_value(); (*b)->bring_value(); uint n= (*a)->cols(); for (uint i= 0; iappend('('); args[0]->print(str); str->append(STRING_WITH_LEN(" is ")); if (! affirmative) str->append(STRING_WITH_LEN("not ")); if (value) str->append(STRING_WITH_LEN("true")); else str->append(STRING_WITH_LEN("false")); str->append(')'); } bool Item_func_truth::val_bool() { bool val= args[0]->val_bool(); if (args[0]->null_value) { /* NULL val IS {TRUE, FALSE} --> FALSE NULL val IS NOT {TRUE, FALSE} --> TRUE */ return (! affirmative); } if (affirmative) { /* {TRUE, FALSE} val IS {TRUE, FALSE} value */ return (val == value); } /* {TRUE, FALSE} val IS NOT {TRUE, FALSE} value */ return (val != value); } longlong Item_func_truth::val_int() { return (val_bool() ? 1 : 0); } bool Item_in_optimizer::fix_left(THD *thd, Item **ref) { if (!args[0]->fixed && args[0]->fix_fields(thd, args) || !cache && !(cache= Item_cache::get_cache(args[0]->result_type()))) return 1; cache->setup(args[0]); if (cache->cols() == 1) { if ((used_tables_cache= args[0]->used_tables())) cache->set_used_tables(OUTER_REF_TABLE_BIT); else cache->set_used_tables(0); } else { uint n= cache->cols(); for (uint i= 0; i < n; i++) { if (args[0]->element_index(i)->used_tables()) ((Item_cache *)cache->element_index(i))->set_used_tables(OUTER_REF_TABLE_BIT); else ((Item_cache *)cache->element_index(i))->set_used_tables(0); } used_tables_cache= args[0]->used_tables(); } not_null_tables_cache= args[0]->not_null_tables(); with_sum_func= args[0]->with_sum_func; const_item_cache= args[0]->const_item(); return 0; } bool Item_in_optimizer::fix_fields(THD *thd, Item **ref) { DBUG_ASSERT(fixed == 0); if (fix_left(thd, ref)) return TRUE; if (args[0]->maybe_null) maybe_null=1; if (!args[1]->fixed && args[1]->fix_fields(thd, args+1)) return TRUE; Item_in_subselect * sub= (Item_in_subselect *)args[1]; if (args[0]->cols() != sub->engine->cols()) { my_error(ER_OPERAND_COLUMNS, MYF(0), args[0]->cols()); return TRUE; } if (args[1]->maybe_null) maybe_null=1; with_sum_func= with_sum_func || args[1]->with_sum_func; used_tables_cache|= args[1]->used_tables(); not_null_tables_cache|= args[1]->not_null_tables(); const_item_cache&= args[1]->const_item(); fixed= 1; return FALSE; } longlong Item_in_optimizer::val_int() { bool tmp; DBUG_ASSERT(fixed == 1); cache->store(args[0]); if (cache->null_value) { if (((Item_in_subselect*)args[1])->is_top_level_item()) { /* We're evaluating "NULL IN (SELECT ...)". The result can be NULL or FALSE, and we can return one instead of another. Just return NULL. */ null_value= 1; } else { if (!((Item_in_subselect*)args[1])->is_correlated && result_for_null_param != UNKNOWN) { /* Use cached value from previous execution */ null_value= result_for_null_param; } else { /* We're evaluating "NULL IN (SELECT ...)". The result is: FALSE if SELECT produces an empty set, or NULL otherwise. We disable the predicates we've pushed down into subselect, run the subselect and see if it has produced any rows. */ Item_in_subselect *item_subs=(Item_in_subselect*)args[1]; if (cache->cols() == 1) { item_subs->set_cond_guard_var(0, FALSE); (void) args[1]->val_bool_result(); result_for_null_param= null_value= !item_subs->engine->no_rows(); item_subs->set_cond_guard_var(0, TRUE); } else { uint i; uint ncols= cache->cols(); /* Turn off the predicates that are based on column compares for which the left part is currently NULL */ for (i= 0; i < ncols; i++) { if (cache->element_index(i)->null_value) item_subs->set_cond_guard_var(i, FALSE); } (void) args[1]->val_bool_result(); result_for_null_param= null_value= !item_subs->engine->no_rows(); /* Turn all predicates back on */ for (i= 0; i < ncols; i++) item_subs->set_cond_guard_var(i, TRUE); } } } return 0; } tmp= args[1]->val_bool_result(); null_value= args[1]->null_value; return tmp; } void Item_in_optimizer::keep_top_level_cache() { cache->keep_array(); save_cache= 1; } void Item_in_optimizer::cleanup() { DBUG_ENTER("Item_in_optimizer::cleanup"); Item_bool_func::cleanup(); if (!save_cache) cache= 0; DBUG_VOID_RETURN; } bool Item_in_optimizer::is_null() { cache->store(args[0]); return (null_value= (cache->null_value || args[1]->is_null())); } longlong Item_func_eq::val_int() { DBUG_ASSERT(fixed == 1); int value= cmp.compare(); return value == 0 ? 1 : 0; } /* Same as Item_func_eq, but NULL = NULL */ void Item_func_equal::fix_length_and_dec() { Item_bool_func2::fix_length_and_dec(); maybe_null=null_value=0; } longlong Item_func_equal::val_int() { DBUG_ASSERT(fixed == 1); return cmp.compare(); } longlong Item_func_ne::val_int() { DBUG_ASSERT(fixed == 1); int value= cmp.compare(); return value != 0 && !null_value ? 1 : 0; } longlong Item_func_ge::val_int() { DBUG_ASSERT(fixed == 1); int value= cmp.compare(); return value >= 0 ? 1 : 0; } longlong Item_func_gt::val_int() { DBUG_ASSERT(fixed == 1); int value= cmp.compare(); return value > 0 ? 1 : 0; } longlong Item_func_le::val_int() { DBUG_ASSERT(fixed == 1); int value= cmp.compare(); return value <= 0 && !null_value ? 1 : 0; } longlong Item_func_lt::val_int() { DBUG_ASSERT(fixed == 1); int value= cmp.compare(); return value < 0 && !null_value ? 1 : 0; } longlong Item_func_strcmp::val_int() { DBUG_ASSERT(fixed == 1); String *a=args[0]->val_str(&tmp_value1); String *b=args[1]->val_str(&tmp_value2); if (!a || !b) { null_value=1; return 0; } int value= sortcmp(a,b,cmp.cmp_collation.collation); null_value=0; return !value ? 0 : (value < 0 ? (longlong) -1 : (longlong) 1); } bool Item_func_opt_neg::eq(const Item *item, bool binary_cmp) const { /* Assume we don't have rtti */ if (this == item) return 1; if (item->type() != FUNC_ITEM) return 0; Item_func *item_func=(Item_func*) item; if (arg_count != item_func->arg_count || functype() != item_func->functype()) return 0; if (negated != ((Item_func_opt_neg *) item_func)->negated) return 0; for (uint i=0; i < arg_count ; i++) if (!args[i]->eq(item_func->arguments()[i], binary_cmp)) return 0; return 1; } void Item_func_interval::fix_length_and_dec() { use_decimal_comparison= (row->element_index(0)->result_type() == DECIMAL_RESULT) || (row->element_index(0)->result_type() == INT_RESULT); if (row->cols() > 8) { bool consts=1; for (uint i=1 ; consts && i < row->cols() ; i++) { consts&= row->element_index(i)->const_item(); } if (consts && (intervals= (interval_range*) sql_alloc(sizeof(interval_range)*(row->cols()-1)))) { if (use_decimal_comparison) { for (uint i=1 ; i < row->cols(); i++) { Item *el= row->element_index(i); interval_range *range= intervals + (i-1); if ((el->result_type() == DECIMAL_RESULT) || (el->result_type() == INT_RESULT)) { range->type= DECIMAL_RESULT; range->dec.init(); my_decimal *dec= el->val_decimal(&range->dec); if (dec != &range->dec) { range->dec= *dec; range->dec.fix_buffer_pointer(); } } else { range->type= REAL_RESULT; range->dbl= el->val_real(); } } } else { for (uint i=1 ; i < row->cols(); i++) { intervals[i-1].dbl= row->element_index(i)->val_real(); } } } } maybe_null= 0; max_length= 2; used_tables_cache|= row->used_tables(); not_null_tables_cache= row->not_null_tables(); with_sum_func= with_sum_func || row->with_sum_func; const_item_cache&= row->const_item(); } /* Execute Item_func_interval() SYNOPSIS Item_func_interval::val_int() NOTES If we are doing a decimal comparison, we are evaluating the first item twice. RETURN -1 if null value, 0 if lower than lowest 1 - arg_count-1 if between args[n] and args[n+1] arg_count if higher than biggest argument */ longlong Item_func_interval::val_int() { DBUG_ASSERT(fixed == 1); double value; my_decimal dec_buf, *dec= NULL; uint i; if (use_decimal_comparison) { dec= row->element_index(0)->val_decimal(&dec_buf); if (row->element_index(0)->null_value) return -1; my_decimal2double(E_DEC_FATAL_ERROR, dec, &value); } else { value= row->element_index(0)->val_real(); if (row->element_index(0)->null_value) return -1; } if (intervals) { // Use binary search to find interval uint start,end; start= 0; end= row->cols()-2; while (start != end) { uint mid= (start + end + 1) / 2; interval_range *range= intervals + mid; my_bool cmp_result; /* The values in the range intervall may have different types, Only do a decimal comparision of the first argument is a decimal and we are comparing against a decimal */ if (dec && range->type == DECIMAL_RESULT) cmp_result= my_decimal_cmp(&range->dec, dec) <= 0; else cmp_result= (range->dbl <= value); if (cmp_result) start= mid; else end= mid - 1; } interval_range *range= intervals+start; return ((dec && range->type == DECIMAL_RESULT) ? my_decimal_cmp(dec, &range->dec) < 0 : value < range->dbl) ? 0 : start + 1; } for (i=1 ; i < row->cols() ; i++) { Item *el= row->element_index(i); if (use_decimal_comparison && ((el->result_type() == DECIMAL_RESULT) || (el->result_type() == INT_RESULT))) { my_decimal e_dec_buf, *e_dec= row->element_index(i)->val_decimal(&e_dec_buf); if (my_decimal_cmp(e_dec, dec) > 0) return i-1; } else if (row->element_index(i)->val_real() > value) return i-1; } return i-1; } /* Perform context analysis of a BETWEEN item tree SYNOPSIS: fix_fields() thd reference to the global context of the query thread tables list of all open tables involved in the query ref pointer to Item* variable where pointer to resulting "fixed" item is to be assigned DESCRIPTION This function performs context analysis (name resolution) and calculates various attributes of the item tree with Item_func_between as its root. The function saves in ref the pointer to the item or to a newly created item that is considered as a replacement for the original one. NOTES Let T0(e)/T1(e) be the value of not_null_tables(e) when e is used on a predicate/function level. Then it's easy to show that: T0(e BETWEEN e1 AND e2) = union(T1(e),T1(e1),T1(e2)) T1(e BETWEEN e1 AND e2) = union(T1(e),intersection(T1(e1),T1(e2))) T0(e NOT BETWEEN e1 AND e2) = union(T1(e),intersection(T1(e1),T1(e2))) T1(e NOT BETWEEN e1 AND e2) = union(T1(e),intersection(T1(e1),T1(e2))) RETURN 0 ok 1 got error */ bool Item_func_between::fix_fields(THD *thd, Item **ref) { if (Item_func_opt_neg::fix_fields(thd, ref)) return 1; thd->lex->current_select->between_count++; /* not_null_tables_cache == union(T1(e),T1(e1),T1(e2)) */ if (pred_level && !negated) return 0; /* not_null_tables_cache == union(T1(e), intersection(T1(e1),T1(e2))) */ not_null_tables_cache= (args[0]->not_null_tables() | (args[1]->not_null_tables() & args[2]->not_null_tables())); return 0; } void Item_func_between::fix_length_and_dec() { max_length= 1; THD *thd= current_thd; /* As some compare functions are generated after sql_yacc, we have to check for out of memory conditions here */ if (!args[0] || !args[1] || !args[2]) return; if ( agg_cmp_type(thd, &cmp_type, args, 3)) return; if (cmp_type == STRING_RESULT && agg_arg_charsets(cmp_collation, args, 3, MY_COLL_CMP_CONV, 1)) return; /* Make a special case of compare with date/time and longlong fields. They are compared as integers, so for const item this time-consuming conversion can be done only once, not for every single comparison */ if (args[0]->real_item()->type() == FIELD_ITEM && thd->lex->sql_command != SQLCOM_CREATE_VIEW && thd->lex->sql_command != SQLCOM_SHOW_CREATE) { Field *field=((Item_field*) (args[0]->real_item()))->field; if (field->can_be_compared_as_longlong()) { /* The following can't be recoded with || as convert_constant_item changes the argument */ if (convert_constant_item(thd, field,&args[1])) cmp_type=INT_RESULT; // Works for all types. if (convert_constant_item(thd, field,&args[2])) cmp_type=INT_RESULT; // Works for all types. } } } longlong Item_func_between::val_int() { // ANSI BETWEEN DBUG_ASSERT(fixed == 1); if (cmp_type == STRING_RESULT) { String *value,*a,*b; value=args[0]->val_str(&value0); if ((null_value=args[0]->null_value)) return 0; a=args[1]->val_str(&value1); b=args[2]->val_str(&value2); if (!args[1]->null_value && !args[2]->null_value) return (longlong) ((sortcmp(value,a,cmp_collation.collation) >= 0 && sortcmp(value,b,cmp_collation.collation) <= 0) != negated); if (args[1]->null_value && args[2]->null_value) null_value=1; else if (args[1]->null_value) { // Set to not null if false range. null_value= sortcmp(value,b,cmp_collation.collation) <= 0; } else { // Set to not null if false range. null_value= sortcmp(value,a,cmp_collation.collation) >= 0; } } else if (cmp_type == INT_RESULT) { longlong value=args[0]->val_int(), a, b; if ((null_value=args[0]->null_value)) return 0; /* purecov: inspected */ a=args[1]->val_int(); b=args[2]->val_int(); if (!args[1]->null_value && !args[2]->null_value) return (longlong) ((value >= a && value <= b) != negated); if (args[1]->null_value && args[2]->null_value) null_value=1; else if (args[1]->null_value) { null_value= value <= b; // not null if false range. } else { null_value= value >= a; } } else if (cmp_type == DECIMAL_RESULT) { my_decimal dec_buf, *dec= args[0]->val_decimal(&dec_buf), a_buf, *a_dec, b_buf, *b_dec; if ((null_value=args[0]->null_value)) return 0; /* purecov: inspected */ a_dec= args[1]->val_decimal(&a_buf); b_dec= args[2]->val_decimal(&b_buf); if (!args[1]->null_value && !args[2]->null_value) return (longlong) ((my_decimal_cmp(dec, a_dec) >= 0 && my_decimal_cmp(dec, b_dec) <= 0) != negated); if (args[1]->null_value && args[2]->null_value) null_value=1; else if (args[1]->null_value) null_value= (my_decimal_cmp(dec, b_dec) <= 0); else null_value= (my_decimal_cmp(dec, a_dec) >= 0); } else { double value= args[0]->val_real(),a,b; if ((null_value=args[0]->null_value)) return 0; /* purecov: inspected */ a= args[1]->val_real(); b= args[2]->val_real(); if (!args[1]->null_value && !args[2]->null_value) return (longlong) ((value >= a && value <= b) != negated); if (args[1]->null_value && args[2]->null_value) null_value=1; else if (args[1]->null_value) { null_value= value <= b; // not null if false range. } else { null_value= value >= a; } } return (longlong) (!null_value && negated); } void Item_func_between::print(String *str) { str->append('('); args[0]->print(str); if (negated) str->append(STRING_WITH_LEN(" not")); str->append(STRING_WITH_LEN(" between ")); args[1]->print(str); str->append(STRING_WITH_LEN(" and ")); args[2]->print(str); str->append(')'); } void Item_func_ifnull::fix_length_and_dec() { agg_result_type(&hybrid_type, args, 2); maybe_null=args[1]->maybe_null; decimals= max(args[0]->decimals, args[1]->decimals); max_length= (hybrid_type == DECIMAL_RESULT || hybrid_type == INT_RESULT) ? (max(args[0]->max_length - args[0]->decimals, args[1]->max_length - args[1]->decimals) + decimals) : max(args[0]->max_length, args[1]->max_length); switch (hybrid_type) { case STRING_RESULT: agg_arg_charsets(collation, args, arg_count, MY_COLL_CMP_CONV, 1); break; case DECIMAL_RESULT: case REAL_RESULT: break; case INT_RESULT: decimals= 0; break; case ROW_RESULT: default: DBUG_ASSERT(0); } cached_field_type= args[0]->field_type(); if (cached_field_type != args[1]->field_type()) cached_field_type= Item_func::field_type(); } uint Item_func_ifnull::decimal_precision() const { int max_int_part=max(args[0]->decimal_int_part(),args[1]->decimal_int_part()); return min(max_int_part + decimals, DECIMAL_MAX_PRECISION); } enum_field_types Item_func_ifnull::field_type() const { return cached_field_type; } Field *Item_func_ifnull::tmp_table_field(TABLE *table) { return tmp_table_field_from_field_type(table); } double Item_func_ifnull::real_op() { DBUG_ASSERT(fixed == 1); double value= args[0]->val_real(); if (!args[0]->null_value) { null_value=0; return value; } value= args[1]->val_real(); if ((null_value=args[1]->null_value)) return 0.0; return value; } longlong Item_func_ifnull::int_op() { DBUG_ASSERT(fixed == 1); longlong value=args[0]->val_int(); if (!args[0]->null_value) { null_value=0; return value; } value=args[1]->val_int(); if ((null_value=args[1]->null_value)) return 0; return value; } my_decimal *Item_func_ifnull::decimal_op(my_decimal *decimal_value) { DBUG_ASSERT(fixed == 1); my_decimal *value= args[0]->val_decimal(decimal_value); if (!args[0]->null_value) { null_value= 0; return value; } value= args[1]->val_decimal(decimal_value); if ((null_value= args[1]->null_value)) return 0; return value; } String * Item_func_ifnull::str_op(String *str) { DBUG_ASSERT(fixed == 1); String *res =args[0]->val_str(str); if (!args[0]->null_value) { null_value=0; res->set_charset(collation.collation); return res; } res=args[1]->val_str(str); if ((null_value=args[1]->null_value)) return 0; res->set_charset(collation.collation); return res; } /* Perform context analysis of an IF item tree SYNOPSIS: fix_fields() thd reference to the global context of the query thread tables list of all open tables involved in the query ref pointer to Item* variable where pointer to resulting "fixed" item is to be assigned DESCRIPTION This function performs context analysis (name resolution) and calculates various attributes of the item tree with Item_func_if as its root. The function saves in ref the pointer to the item or to a newly created item that is considered as a replacement for the original one. NOTES Let T0(e)/T1(e) be the value of not_null_tables(e) when e is used on a predicate/function level. Then it's easy to show that: T0(IF(e,e1,e2) = T1(IF(e,e1,e2)) T1(IF(e,e1,e2)) = intersection(T1(e1),T1(e2)) RETURN 0 ok 1 got error */ bool Item_func_if::fix_fields(THD *thd, Item **ref) { DBUG_ASSERT(fixed == 0); args[0]->top_level_item(); if (Item_func::fix_fields(thd, ref)) return 1; not_null_tables_cache= (args[1]->not_null_tables() & args[2]->not_null_tables()); return 0; } void Item_func_if::fix_length_and_dec() { maybe_null=args[1]->maybe_null || args[2]->maybe_null; decimals= max(args[1]->decimals, args[2]->decimals); unsigned_flag=args[1]->unsigned_flag && args[2]->unsigned_flag; enum Item_result arg1_type=args[1]->result_type(); enum Item_result arg2_type=args[2]->result_type(); bool null1=args[1]->const_item() && args[1]->null_value; bool null2=args[2]->const_item() && args[2]->null_value; if (null1) { cached_result_type= arg2_type; collation.set(args[2]->collation.collation); } else if (null2) { cached_result_type= arg1_type; collation.set(args[1]->collation.collation); } else { agg_result_type(&cached_result_type, args+1, 2); if (cached_result_type == STRING_RESULT) { if (agg_arg_charsets(collation, args+1, 2, MY_COLL_ALLOW_CONV, 1)) return; } else { collation.set(&my_charset_bin); // Number } } if ((cached_result_type == DECIMAL_RESULT ) || (cached_result_type == INT_RESULT)) { int len1= args[1]->max_length - args[1]->decimals - (args[1]->unsigned_flag ? 0 : 1); int len2= args[2]->max_length - args[2]->decimals - (args[2]->unsigned_flag ? 0 : 1); max_length=max(len1, len2) + decimals + (unsigned_flag ? 0 : 1); } else max_length= max(args[1]->max_length, args[2]->max_length); } uint Item_func_if::decimal_precision() const { int precision=(max(args[1]->decimal_int_part(),args[2]->decimal_int_part())+ decimals); return min(precision, DECIMAL_MAX_PRECISION); } double Item_func_if::val_real() { DBUG_ASSERT(fixed == 1); Item *arg= args[0]->val_bool() ? args[1] : args[2]; double value= arg->val_real(); null_value=arg->null_value; return value; } longlong Item_func_if::val_int() { DBUG_ASSERT(fixed == 1); Item *arg= args[0]->val_bool() ? args[1] : args[2]; longlong value=arg->val_int(); null_value=arg->null_value; return value; } String * Item_func_if::val_str(String *str) { DBUG_ASSERT(fixed == 1); Item *arg= args[0]->val_bool() ? args[1] : args[2]; String *res=arg->val_str(str); if (res) res->set_charset(collation.collation); null_value=arg->null_value; return res; } my_decimal * Item_func_if::val_decimal(my_decimal *decimal_value) { DBUG_ASSERT(fixed == 1); Item *arg= args[0]->val_bool() ? args[1] : args[2]; my_decimal *value= arg->val_decimal(decimal_value); null_value= arg->null_value; return value; } void Item_func_nullif::fix_length_and_dec() { Item_bool_func2::fix_length_and_dec(); maybe_null=1; if (args[0]) // Only false if EOM { max_length=args[0]->max_length; decimals=args[0]->decimals; unsigned_flag= args[0]->unsigned_flag; cached_result_type= args[0]->result_type(); if (cached_result_type == STRING_RESULT && agg_arg_charsets(collation, args, arg_count, MY_COLL_CMP_CONV, 1)) return; } } /* nullif () returns NULL if arguments are equal, else it returns the first argument. Note that we have to evaluate the first argument twice as the compare may have been done with a different type than return value */ double Item_func_nullif::val_real() { DBUG_ASSERT(fixed == 1); double value; if (!cmp.compare()) { null_value=1; return 0.0; } value= args[0]->val_real(); null_value=args[0]->null_value; return value; } longlong Item_func_nullif::val_int() { DBUG_ASSERT(fixed == 1); longlong value; if (!cmp.compare()) { null_value=1; return 0; } value=args[0]->val_int(); null_value=args[0]->null_value; return value; } String * Item_func_nullif::val_str(String *str) { DBUG_ASSERT(fixed == 1); String *res; if (!cmp.compare()) { null_value=1; return 0; } res=args[0]->val_str(str); null_value=args[0]->null_value; return res; } my_decimal * Item_func_nullif::val_decimal(my_decimal * decimal_value) { DBUG_ASSERT(fixed == 1); my_decimal *res; if (!cmp.compare()) { null_value=1; return 0; } res= args[0]->val_decimal(decimal_value); null_value= args[0]->null_value; return res; } bool Item_func_nullif::is_null() { return (null_value= (!cmp.compare() ? 1 : args[0]->null_value)); } /* CASE expression Return the matching ITEM or NULL if all compares (including else) failed */ Item *Item_func_case::find_item(String *str) { String *first_expr_str, *tmp; my_decimal *first_expr_dec, first_expr_dec_val; longlong first_expr_int; double first_expr_real; char buff[MAX_FIELD_WIDTH]; String buff_str(buff,sizeof(buff),default_charset()); /* These will be initialized later */ LINT_INIT(first_expr_str); LINT_INIT(first_expr_int); LINT_INIT(first_expr_real); LINT_INIT(first_expr_dec); if (first_expr_num != -1) { switch (cmp_type) { case STRING_RESULT: // We can't use 'str' here as this may be overwritten if (!(first_expr_str= args[first_expr_num]->val_str(&buff_str))) return else_expr_num != -1 ? args[else_expr_num] : 0; // Impossible break; case INT_RESULT: first_expr_int= args[first_expr_num]->val_int(); if (args[first_expr_num]->null_value) return else_expr_num != -1 ? args[else_expr_num] : 0; break; case REAL_RESULT: first_expr_real= args[first_expr_num]->val_real(); if (args[first_expr_num]->null_value) return else_expr_num != -1 ? args[else_expr_num] : 0; break; case DECIMAL_RESULT: first_expr_dec= args[first_expr_num]->val_decimal(&first_expr_dec_val); if (args[first_expr_num]->null_value) return else_expr_num != -1 ? args[else_expr_num] : 0; break; case ROW_RESULT: default: // This case should never be chosen DBUG_ASSERT(0); break; } } // Compare every WHEN argument with it and return the first match for (uint i=0 ; i < ncases ; i+=2) { if (first_expr_num == -1) { // No expression between CASE and the first WHEN if (args[i]->val_bool()) return args[i+1]; continue; } switch (cmp_type) { case STRING_RESULT: if ((tmp=args[i]->val_str(str))) // If not null if (sortcmp(tmp,first_expr_str,cmp_collation.collation)==0) return args[i+1]; break; case INT_RESULT: if (args[i]->val_int()==first_expr_int && !args[i]->null_value) return args[i+1]; break; case REAL_RESULT: if (args[i]->val_real() == first_expr_real && !args[i]->null_value) return args[i+1]; break; case DECIMAL_RESULT: { my_decimal value; if (my_decimal_cmp(args[i]->val_decimal(&value), first_expr_dec) == 0) return args[i+1]; break; } case ROW_RESULT: default: // This case should never be chosen DBUG_ASSERT(0); break; } } // No, WHEN clauses all missed, return ELSE expression return else_expr_num != -1 ? args[else_expr_num] : 0; } String *Item_func_case::val_str(String *str) { DBUG_ASSERT(fixed == 1); String *res; Item *item=find_item(str); if (!item) { null_value=1; return 0; } null_value= 0; if (!(res=item->val_str(str))) null_value= 1; return res; } longlong Item_func_case::val_int() { DBUG_ASSERT(fixed == 1); char buff[MAX_FIELD_WIDTH]; String dummy_str(buff,sizeof(buff),default_charset()); Item *item=find_item(&dummy_str); longlong res; if (!item) { null_value=1; return 0; } res=item->val_int(); null_value=item->null_value; return res; } double Item_func_case::val_real() { DBUG_ASSERT(fixed == 1); char buff[MAX_FIELD_WIDTH]; String dummy_str(buff,sizeof(buff),default_charset()); Item *item=find_item(&dummy_str); double res; if (!item) { null_value=1; return 0; } res= item->val_real(); null_value=item->null_value; return res; } my_decimal *Item_func_case::val_decimal(my_decimal *decimal_value) { DBUG_ASSERT(fixed == 1); char buff[MAX_FIELD_WIDTH]; String dummy_str(buff, sizeof(buff), default_charset()); Item *item= find_item(&dummy_str); my_decimal *res; if (!item) { null_value=1; return 0; } res= item->val_decimal(decimal_value); null_value= item->null_value; return res; } bool Item_func_case::fix_fields(THD *thd, Item **ref) { /* buff should match stack usage from Item_func_case::val_int() -> Item_func_case::find_item() */ #ifndef EMBEDDED_LIBRARY char buff[MAX_FIELD_WIDTH*2+sizeof(String)*2+sizeof(String*)*2+sizeof(double)*2+sizeof(longlong)*2]; #endif bool res= Item_func::fix_fields(thd, ref); /* Call check_stack_overrun after fix_fields to be sure that stack variable is not optimized away */ if (check_stack_overrun(thd, STACK_MIN_SIZE, buff)) return TRUE; // Fatal error flag is set! return res; } void Item_func_case::fix_length_and_dec() { Item **agg; uint nagg; THD *thd= current_thd; if (!(agg= (Item**) sql_alloc(sizeof(Item*)*(ncases+1)))) return; /* Aggregate all THEN and ELSE expression types and collations when string result */ for (nagg= 0 ; nagg < ncases/2 ; nagg++) agg[nagg]= args[nagg*2+1]; if (else_expr_num != -1) agg[nagg++]= args[else_expr_num]; agg_result_type(&cached_result_type, agg, nagg); if ((cached_result_type == STRING_RESULT) && agg_arg_charsets(collation, agg, nagg, MY_COLL_ALLOW_CONV, 1)) return; /* Aggregate first expression and all THEN expression types and collations when string comparison */ if (first_expr_num != -1) { agg[0]= args[first_expr_num]; for (nagg= 0; nagg < ncases/2 ; nagg++) agg[nagg+1]= args[nagg*2]; nagg++; if (agg_cmp_type(thd, &cmp_type, agg, nagg)) return; if ((cmp_type == STRING_RESULT) && agg_arg_charsets(cmp_collation, agg, nagg, MY_COLL_CMP_CONV, 1)) return; } if (else_expr_num == -1 || args[else_expr_num]->maybe_null) maybe_null=1; max_length=0; decimals=0; for (uint i=0 ; i < ncases ; i+=2) { set_if_bigger(max_length,args[i+1]->max_length); set_if_bigger(decimals,args[i+1]->decimals); } if (else_expr_num != -1) { set_if_bigger(max_length,args[else_expr_num]->max_length); set_if_bigger(decimals,args[else_expr_num]->decimals); } } uint Item_func_case::decimal_precision() const { int max_int_part=0; for (uint i=0 ; i < ncases ; i+=2) set_if_bigger(max_int_part, args[i+1]->decimal_int_part()); if (else_expr_num != -1) set_if_bigger(max_int_part, args[else_expr_num]->decimal_int_part()); return min(max_int_part + decimals, DECIMAL_MAX_PRECISION); } /* TODO: Fix this so that it prints the whole CASE expression */ void Item_func_case::print(String *str) { str->append(STRING_WITH_LEN("(case ")); if (first_expr_num != -1) { args[first_expr_num]->print(str); str->append(' '); } for (uint i=0 ; i < ncases ; i+=2) { str->append(STRING_WITH_LEN("when ")); args[i]->print(str); str->append(STRING_WITH_LEN(" then ")); args[i+1]->print(str); str->append(' '); } if (else_expr_num != -1) { str->append(STRING_WITH_LEN("else ")); args[else_expr_num]->print(str); str->append(' '); } str->append(STRING_WITH_LEN("end)")); } /* Coalesce - return first not NULL argument. */ String *Item_func_coalesce::str_op(String *str) { DBUG_ASSERT(fixed == 1); null_value=0; for (uint i=0 ; i < arg_count ; i++) { String *res; if ((res=args[i]->val_str(str))) return res; } null_value=1; return 0; } longlong Item_func_coalesce::int_op() { DBUG_ASSERT(fixed == 1); null_value=0; for (uint i=0 ; i < arg_count ; i++) { longlong res=args[i]->val_int(); if (!args[i]->null_value) return res; } null_value=1; return 0; } double Item_func_coalesce::real_op() { DBUG_ASSERT(fixed == 1); null_value=0; for (uint i=0 ; i < arg_count ; i++) { double res= args[i]->val_real(); if (!args[i]->null_value) return res; } null_value=1; return 0; } my_decimal *Item_func_coalesce::decimal_op(my_decimal *decimal_value) { DBUG_ASSERT(fixed == 1); null_value= 0; for (uint i= 0; i < arg_count; i++) { my_decimal *res= args[i]->val_decimal(decimal_value); if (!args[i]->null_value) return res; } null_value=1; return 0; } void Item_func_coalesce::fix_length_and_dec() { agg_result_type(&hybrid_type, args, arg_count); switch (hybrid_type) { case STRING_RESULT: count_only_length(); decimals= NOT_FIXED_DEC; agg_arg_charsets(collation, args, arg_count, MY_COLL_ALLOW_CONV, 1); break; case DECIMAL_RESULT: count_decimal_length(); break; case REAL_RESULT: count_real_length(); break; case INT_RESULT: count_only_length(); decimals= 0; break; case ROW_RESULT: default: DBUG_ASSERT(0); } } /**************************************************************************** Classes and function for the IN operator ****************************************************************************/ /* Determine which of the signed longlong arguments is bigger SYNOPSIS cmp_longs() a_val left argument b_val right argument DESCRIPTION This function will compare two signed longlong arguments and will return -1, 0, or 1 if left argument is smaller than, equal to or greater than the right argument. RETURN VALUE -1 left argument is smaller than the right argument. 0 left argument is equal to the right argument. 1 left argument is greater than the right argument. */ static inline int cmp_longs (longlong a_val, longlong b_val) { return a_val < b_val ? -1 : a_val == b_val ? 0 : 1; } /* Determine which of the unsigned longlong arguments is bigger SYNOPSIS cmp_ulongs() a_val left argument b_val right argument DESCRIPTION This function will compare two unsigned longlong arguments and will return -1, 0, or 1 if left argument is smaller than, equal to or greater than the right argument. RETURN VALUE -1 left argument is smaller than the right argument. 0 left argument is equal to the right argument. 1 left argument is greater than the right argument. */ static inline int cmp_ulongs (ulonglong a_val, ulonglong b_val) { return a_val < b_val ? -1 : a_val == b_val ? 0 : 1; } /* Compare two integers in IN value list format (packed_longlong) SYNOPSIS cmp_longlong() cmp_arg an argument passed to the calling function (qsort2) a left argument b right argument DESCRIPTION This function will compare two integer arguments in the IN value list format and will return -1, 0, or 1 if left argument is smaller than, equal to or greater than the right argument. It's used in sorting the IN values list and finding an element in it. Depending on the signedness of the arguments cmp_longlong() will compare them as either signed (using cmp_longs()) or unsigned (using cmp_ulongs()). RETURN VALUE -1 left argument is smaller than the right argument. 0 left argument is equal to the right argument. 1 left argument is greater than the right argument. */ int cmp_longlong(void *cmp_arg, in_longlong::packed_longlong *a, in_longlong::packed_longlong *b) { if (a->unsigned_flag != b->unsigned_flag) { /* One of the args is unsigned and is too big to fit into the positive signed range. Report no match. */ if (a->unsigned_flag && ((ulonglong) a->val) > (ulonglong) LONGLONG_MAX || b->unsigned_flag && ((ulonglong) b->val) > (ulonglong) LONGLONG_MAX) return a->unsigned_flag ? 1 : -1; /* Although the signedness differs both args can fit into the signed positive range. Make them signed and compare as usual. */ return cmp_longs (a->val, b->val); } if (a->unsigned_flag) return cmp_ulongs ((ulonglong) a->val, (ulonglong) b->val); else return cmp_longs (a->val, b->val); } static int cmp_double(void *cmp_arg, double *a,double *b) { return *a < *b ? -1 : *a == *b ? 0 : 1; } static int cmp_row(void *cmp_arg, cmp_item_row *a, cmp_item_row *b) { return a->compare(b); } static int cmp_decimal(void *cmp_arg, my_decimal *a, my_decimal *b) { /* We need call of fixing buffer pointer, because fast sort just copy decimal buffers in memory and pointers left pointing on old buffer place */ a->fix_buffer_pointer(); b->fix_buffer_pointer(); return my_decimal_cmp(a, b); } int in_vector::find(Item *item) { byte *result=get_value(item); if (!result || !used_count) return 0; // Null value uint start,end; start=0; end=used_count-1; while (start != end) { uint mid=(start+end+1)/2; int res; if ((res=(*compare)(collation, base+mid*size, result)) == 0) return 1; if (res < 0) start=mid; else end=mid-1; } return (int) ((*compare)(collation, base+start*size, result) == 0); } in_string::in_string(uint elements,qsort2_cmp cmp_func, CHARSET_INFO *cs) :in_vector(elements, sizeof(String), cmp_func, cs), tmp(buff, sizeof(buff), &my_charset_bin) {} in_string::~in_string() { if (base) { // base was allocated with help of sql_alloc => following is OK for (uint i=0 ; i < count ; i++) ((String*) base)[i].free(); } } void in_string::set(uint pos,Item *item) { String *str=((String*) base)+pos; String *res=item->val_str(str); if (res && res != str) { if (res->uses_buffer_owned_by(str)) res->copy(); *str= *res; } if (!str->charset()) { CHARSET_INFO *cs; if (!(cs= item->collation.collation)) cs= &my_charset_bin; // Should never happen for STR items str->set_charset(cs); } } byte *in_string::get_value(Item *item) { return (byte*) item->val_str(&tmp); } in_row::in_row(uint elements, Item * item) { base= (char*) new cmp_item_row[count= elements]; size= sizeof(cmp_item_row); compare= (qsort2_cmp) cmp_row; tmp.store_value(item); /* We need to reset these as otherwise we will call sort() with uninitialized (even if not used) elements */ used_count= elements; collation= 0; } in_row::~in_row() { if (base) delete [] (cmp_item_row*) base; } byte *in_row::get_value(Item *item) { tmp.store_value(item); if (item->is_null()) return 0; return (byte *)&tmp; } void in_row::set(uint pos, Item *item) { DBUG_ENTER("in_row::set"); DBUG_PRINT("enter", ("pos %u item 0x%lx", pos, (ulong) item)); ((cmp_item_row*) base)[pos].store_value_by_template(&tmp, item); DBUG_VOID_RETURN; } in_longlong::in_longlong(uint elements) :in_vector(elements,sizeof(packed_longlong),(qsort2_cmp) cmp_longlong, 0) {} void in_longlong::set(uint pos,Item *item) { struct packed_longlong *buff= &((packed_longlong*) base)[pos]; buff->val= item->val_int(); buff->unsigned_flag= item->unsigned_flag; } byte *in_longlong::get_value(Item *item) { tmp.val= item->val_int(); if (item->null_value) return 0; tmp.unsigned_flag= item->unsigned_flag; return (byte*) &tmp; } in_double::in_double(uint elements) :in_vector(elements,sizeof(double),(qsort2_cmp) cmp_double, 0) {} void in_double::set(uint pos,Item *item) { ((double*) base)[pos]= item->val_real(); } byte *in_double::get_value(Item *item) { tmp= item->val_real(); if (item->null_value) return 0; /* purecov: inspected */ return (byte*) &tmp; } in_decimal::in_decimal(uint elements) :in_vector(elements, sizeof(my_decimal),(qsort2_cmp) cmp_decimal, 0) {} void in_decimal::set(uint pos, Item *item) { /* as far as 'item' is constant, we can store reference on my_decimal */ my_decimal *dec= ((my_decimal *)base) + pos; dec->len= DECIMAL_BUFF_LENGTH; dec->fix_buffer_pointer(); my_decimal *res= item->val_decimal(dec); /* if item->val_decimal() is evaluated to NULL then res == 0 */ if (!item->null_value && res != dec) my_decimal2decimal(res, dec); } byte *in_decimal::get_value(Item *item) { my_decimal *result= item->val_decimal(&val); if (item->null_value) return 0; return (byte *)result; } cmp_item* cmp_item::get_comparator(Item_result type, CHARSET_INFO *cs) { switch (type) { case STRING_RESULT: return new cmp_item_sort_string(cs); case INT_RESULT: return new cmp_item_int; case REAL_RESULT: return new cmp_item_real; case ROW_RESULT: return new cmp_item_row; case DECIMAL_RESULT: return new cmp_item_decimal; default: DBUG_ASSERT(0); break; } return 0; // to satisfy compiler :) } cmp_item* cmp_item_sort_string::make_same() { return new cmp_item_sort_string_in_static(cmp_charset); } cmp_item* cmp_item_int::make_same() { return new cmp_item_int(); } cmp_item* cmp_item_real::make_same() { return new cmp_item_real(); } cmp_item* cmp_item_row::make_same() { return new cmp_item_row(); } cmp_item_row::~cmp_item_row() { DBUG_ENTER("~cmp_item_row"); DBUG_PRINT("enter",("this: 0x%lx", (long) this)); if (comparators) { for (uint i= 0; i < n; i++) { if (comparators[i]) delete comparators[i]; } } DBUG_VOID_RETURN; } void cmp_item_row::store_value(Item *item) { DBUG_ENTER("cmp_item_row::store_value"); n= item->cols(); if (!comparators) comparators= (cmp_item **) current_thd->calloc(sizeof(cmp_item *)*n); if (comparators) { item->bring_value(); item->null_value= 0; for (uint i=0; i < n; i++) { if (!comparators[i]) if (!(comparators[i]= cmp_item::get_comparator(item->element_index(i)->result_type(), item->element_index(i)->collation.collation))) break; // new failed comparators[i]->store_value(item->element_index(i)); item->null_value|= item->element_index(i)->null_value; } } DBUG_VOID_RETURN; } void cmp_item_row::store_value_by_template(cmp_item *t, Item *item) { cmp_item_row *tmpl= (cmp_item_row*) t; if (tmpl->n != item->cols()) { my_error(ER_OPERAND_COLUMNS, MYF(0), tmpl->n); return; } n= tmpl->n; if ((comparators= (cmp_item **) sql_alloc(sizeof(cmp_item *)*n))) { item->bring_value(); item->null_value= 0; for (uint i=0; i < n; i++) { if (!(comparators[i]= tmpl->comparators[i]->make_same())) break; // new failed comparators[i]->store_value_by_template(tmpl->comparators[i], item->element_index(i)); item->null_value|= item->element_index(i)->null_value; } } } int cmp_item_row::cmp(Item *arg) { arg->null_value= 0; if (arg->cols() != n) { my_error(ER_OPERAND_COLUMNS, MYF(0), n); return 1; } bool was_null= 0; arg->bring_value(); for (uint i=0; i < n; i++) { if (comparators[i]->cmp(arg->element_index(i))) { if (!arg->element_index(i)->null_value) return 1; was_null= 1; } } return (arg->null_value= was_null); } int cmp_item_row::compare(cmp_item *c) { cmp_item_row *l_cmp= (cmp_item_row *) c; for (uint i=0; i < n; i++) { int res; if ((res= comparators[i]->compare(l_cmp->comparators[i]))) return res; } return 0; } void cmp_item_decimal::store_value(Item *item) { my_decimal *val= item->val_decimal(&value); /* val may be zero if item is nnull */ if (val && val != &value) my_decimal2decimal(val, &value); } int cmp_item_decimal::cmp(Item *arg) { my_decimal tmp_buf, *tmp= arg->val_decimal(&tmp_buf); if (arg->null_value) return 1; return my_decimal_cmp(&value, tmp); } int cmp_item_decimal::compare(cmp_item *arg) { cmp_item_decimal *l_cmp= (cmp_item_decimal*) arg; return my_decimal_cmp(&value, &l_cmp->value); } cmp_item* cmp_item_decimal::make_same() { return new cmp_item_decimal(); } bool Item_func_in::nulls_in_row() { Item **arg,**arg_end; for (arg= args+1, arg_end= args+arg_count; arg != arg_end ; arg++) { if ((*arg)->null_inside()) return 1; } return 0; } /* Perform context analysis of an IN item tree SYNOPSIS: fix_fields() thd reference to the global context of the query thread tables list of all open tables involved in the query ref pointer to Item* variable where pointer to resulting "fixed" item is to be assigned DESCRIPTION This function performs context analysis (name resolution) and calculates various attributes of the item tree with Item_func_in as its root. The function saves in ref the pointer to the item or to a newly created item that is considered as a replacement for the original one. NOTES Let T0(e)/T1(e) be the value of not_null_tables(e) when e is used on a predicate/function level. Then it's easy to show that: T0(e IN(e1,...,en)) = union(T1(e),intersection(T1(ei))) T1(e IN(e1,...,en)) = union(T1(e),intersection(T1(ei))) T0(e NOT IN(e1,...,en)) = union(T1(e),union(T1(ei))) T1(e NOT IN(e1,...,en)) = union(T1(e),intersection(T1(ei))) RETURN 0 ok 1 got error */ bool Item_func_in::fix_fields(THD *thd, Item **ref) { Item **arg, **arg_end; if (Item_func_opt_neg::fix_fields(thd, ref)) return 1; /* not_null_tables_cache == union(T1(e),union(T1(ei))) */ if (pred_level && negated) return 0; /* not_null_tables_cache = union(T1(e),intersection(T1(ei))) */ not_null_tables_cache= ~(table_map) 0; for (arg= args + 1, arg_end= args + arg_count; arg != arg_end; arg++) not_null_tables_cache&= (*arg)->not_null_tables(); not_null_tables_cache|= (*args)->not_null_tables(); return 0; } static int srtcmp_in(CHARSET_INFO *cs, const String *x,const String *y) { return cs->coll->strnncollsp(cs, (uchar *) x->ptr(),x->length(), (uchar *) y->ptr(),y->length(), 0); } void Item_func_in::fix_length_and_dec() { Item **arg, **arg_end; uint const_itm= 1; THD *thd= current_thd; if (agg_cmp_type(thd, &cmp_type, args, arg_count)) return; if (cmp_type == STRING_RESULT && agg_arg_charsets(cmp_collation, args, arg_count, MY_COLL_CMP_CONV, 1)) return; for (arg=args+1, arg_end=args+arg_count; arg != arg_end ; arg++) { if (!arg[0]->const_item()) { const_itm= 0; break; } } /* Row item with NULLs inside can return NULL or FALSE => they can't be processed as static */ if (const_itm && !nulls_in_row()) { /* IN must compare INT/DATE/DATETIME/TIMESTAMP columns and constants as int values (the same way as equality does). So we must check here if the column on the left and all the constant values on the right can be compared as integers and adjust the comparison type accordingly. */ if (args[0]->real_item()->type() == FIELD_ITEM && thd->lex->sql_command != SQLCOM_CREATE_VIEW && thd->lex->sql_command != SQLCOM_SHOW_CREATE && cmp_type != INT_RESULT) { Field *field= ((Item_field*) (args[0]->real_item()))->field; if (field->can_be_compared_as_longlong()) { bool all_converted= TRUE; for (arg=args+1, arg_end=args+arg_count; arg != arg_end ; arg++) { if (!convert_constant_item (thd, field, &arg[0])) all_converted= FALSE; } if (all_converted) cmp_type= INT_RESULT; } } switch (cmp_type) { case STRING_RESULT: array=new in_string(arg_count-1,(qsort2_cmp) srtcmp_in, cmp_collation.collation); break; case INT_RESULT: array= new in_longlong(arg_count-1); break; case REAL_RESULT: array= new in_double(arg_count-1); break; case ROW_RESULT: array= new in_row(arg_count-1, args[0]); break; case DECIMAL_RESULT: array= new in_decimal(arg_count - 1); break; default: DBUG_ASSERT(0); return; } if (array && !(thd->is_fatal_error)) // If not EOM { uint j=0; for (uint i=1 ; i < arg_count ; i++) { array->set(j,args[i]); if (!args[i]->null_value) // Skip NULL values j++; else have_null= 1; } if ((array->used_count=j)) array->sort(); } } else { in_item= cmp_item::get_comparator(cmp_type, cmp_collation.collation); if (cmp_type == STRING_RESULT) in_item->cmp_charset= cmp_collation.collation; } max_length= 1; } void Item_func_in::print(String *str) { str->append('('); args[0]->print(str); if (negated) str->append(STRING_WITH_LEN(" not")); str->append(STRING_WITH_LEN(" in (")); print_args(str, 1); str->append(STRING_WITH_LEN("))")); } longlong Item_func_in::val_int() { DBUG_ASSERT(fixed == 1); if (array) { int tmp=array->find(args[0]); null_value=args[0]->null_value || (!tmp && have_null); return (longlong) (!null_value && tmp != negated); } in_item->store_value(args[0]); if ((null_value=args[0]->null_value)) return 0; have_null= 0; for (uint i=1 ; i < arg_count ; i++) { if (!in_item->cmp(args[i]) && !args[i]->null_value) return (longlong) (!negated); have_null|= args[i]->null_value; } null_value= have_null; return (longlong) (!null_value && negated); } longlong Item_func_bit_or::val_int() { DBUG_ASSERT(fixed == 1); ulonglong arg1= (ulonglong) args[0]->val_int(); if (args[0]->null_value) { null_value=1; /* purecov: inspected */ return 0; /* purecov: inspected */ } ulonglong arg2= (ulonglong) args[1]->val_int(); if (args[1]->null_value) { null_value=1; return 0; } null_value=0; return (longlong) (arg1 | arg2); } longlong Item_func_bit_and::val_int() { DBUG_ASSERT(fixed == 1); ulonglong arg1= (ulonglong) args[0]->val_int(); if (args[0]->null_value) { null_value=1; /* purecov: inspected */ return 0; /* purecov: inspected */ } ulonglong arg2= (ulonglong) args[1]->val_int(); if (args[1]->null_value) { null_value=1; /* purecov: inspected */ return 0; /* purecov: inspected */ } null_value=0; return (longlong) (arg1 & arg2); } Item_cond::Item_cond(THD *thd, Item_cond *item) :Item_bool_func(thd, item), abort_on_null(item->abort_on_null), and_tables_cache(item->and_tables_cache) { /* item->list will be copied by copy_andor_arguments() call */ } void Item_cond::copy_andor_arguments(THD *thd, Item_cond *item) { List_iterator_fast li(item->list); while (Item *it= li++) list.push_back(it->copy_andor_structure(thd)); } bool Item_cond::fix_fields(THD *thd, Item **ref) { DBUG_ASSERT(fixed == 0); List_iterator li(list); Item *item; #ifndef EMBEDDED_LIBRARY char buff[sizeof(char*)]; // Max local vars in function #endif not_null_tables_cache= used_tables_cache= 0; const_item_cache= 1; /* and_table_cache is the value that Item_cond_or() returns for not_null_tables() */ and_tables_cache= ~(table_map) 0; if (check_stack_overrun(thd, STACK_MIN_SIZE, buff)) return TRUE; // Fatal error flag is set! /* The following optimization reduces the depth of an AND-OR tree. E.g. a WHERE clause like F1 AND (F2 AND (F2 AND F4)) is parsed into a tree with the same nested structure as defined by braces. This optimization will transform such tree into AND (F1, F2, F3, F4). Trees of OR items are flattened as well: ((F1 OR F2) OR (F3 OR F4)) => OR (F1, F2, F3, F4) Items for removed AND/OR levels will dangle until the death of the entire statement. The optimization is currently prepared statements and stored procedures friendly as it doesn't allocate any memory and its effects are durable (i.e. do not depend on PS/SP arguments). */ while ((item=li++)) { table_map tmp_table_map; while (item->type() == Item::COND_ITEM && ((Item_cond*) item)->functype() == functype() && !((Item_cond*) item)->list.is_empty()) { // Identical function li.replace(((Item_cond*) item)->list); ((Item_cond*) item)->list.empty(); item= *li.ref(); // new current item } if (abort_on_null) item->top_level_item(); // item can be substituted in fix_fields if ((!item->fixed && item->fix_fields(thd, li.ref())) || (item= *li.ref())->check_cols(1)) return TRUE; /* purecov: inspected */ used_tables_cache|= item->used_tables(); if (item->const_item()) and_tables_cache= (table_map) 0; else { tmp_table_map= item->not_null_tables(); not_null_tables_cache|= tmp_table_map; and_tables_cache&= tmp_table_map; const_item_cache= FALSE; } with_sum_func= with_sum_func || item->with_sum_func; with_subselect|= item->with_subselect; if (item->maybe_null) maybe_null=1; } thd->lex->current_select->cond_count+= list.elements; fix_length_and_dec(); fixed= 1; return FALSE; } bool Item_cond::walk(Item_processor processor, byte *arg) { List_iterator_fast li(list); Item *item; while ((item= li++)) if (item->walk(processor, arg)) return 1; return Item_func::walk(processor, arg); } /* Transform an Item_cond object with a transformer callback function SYNOPSIS transform() transformer the transformer callback function to be applied to the nodes of the tree of the object arg parameter to be passed to the transformer DESCRIPTION The function recursively applies the transform method to each member item of the condition list. If the call of the method for a member item returns a new item the old item is substituted for a new one. After this the transformer is applied to the root node of the Item_cond object. RETURN VALUES Item returned as the result of transformation of the root node */ Item *Item_cond::transform(Item_transformer transformer, byte *arg) { DBUG_ASSERT(!current_thd->is_stmt_prepare()); List_iterator li(list); Item *item; while ((item= li++)) { Item *new_item= item->transform(transformer, arg); if (!new_item) return 0; /* THD::change_item_tree() should be called only if the tree was really transformed, i.e. when a new item has been created. Otherwise we'll be allocating a lot of unnecessary memory for change records at each execution. */ if (new_item != item) current_thd->change_item_tree(li.ref(), new_item); } return Item_func::transform(transformer, arg); } /* Compile Item_cond object with a processor and a transformer callback functions SYNOPSIS compile() analyzer the analyzer callback function to be applied to the nodes of the tree of the object arg_p in/out parameter to be passed to the analyzer transformer the transformer callback function to be applied to the nodes of the tree of the object arg_t parameter to be passed to the transformer DESCRIPTION First the function applies the analyzer to the root node of the Item_func object. Then if the analyzer succeeeds (returns TRUE) the function recursively applies the compile method to member item of the condition list. If the call of the method for a member item returns a new item the old item is substituted for a new one. After this the transformer is applied to the root node of the Item_cond object. RETURN VALUES Item returned as the result of transformation of the root node */ Item *Item_cond::compile(Item_analyzer analyzer, byte **arg_p, Item_transformer transformer, byte *arg_t) { if (!(this->*analyzer)(arg_p)) return 0; List_iterator li(list); Item *item; while ((item= li++)) { /* The same parameter value of arg_p must be passed to analyze any argument of the condition formula. */ byte *arg_v= *arg_p; Item *new_item= item->compile(analyzer, &arg_v, transformer, arg_t); if (new_item && new_item != item) li.replace(new_item); } return Item_func::transform(transformer, arg_t); } void Item_cond::traverse_cond(Cond_traverser traverser, void *arg, traverse_order order) { List_iterator li(list); Item *item; switch(order) { case(PREFIX): (*traverser)(this, arg); while ((item= li++)) { item->traverse_cond(traverser, arg, order); } (*traverser)(NULL, arg); break; case(POSTFIX): while ((item= li++)) { item->traverse_cond(traverser, arg, order); } (*traverser)(this, arg); } } /* Move SUM items out from item tree and replace with reference SYNOPSIS split_sum_func() thd Thread handler ref_pointer_array Pointer to array of reference fields fields All fields in select NOTES This function is run on all expression (SELECT list, WHERE, HAVING etc) that have or refer (HAVING) to a SUM expression. The split is done to get an unique item for each SUM function so that we can easily find and calculate them. (Calculation done by update_sum_func() and copy_sum_funcs() in sql_select.cc) */ void Item_cond::split_sum_func(THD *thd, Item **ref_pointer_array, List &fields) { List_iterator li(list); Item *item; while ((item= li++)) item->split_sum_func2(thd, ref_pointer_array, fields, li.ref(), TRUE); } table_map Item_cond::used_tables() const { // This caches used_tables return used_tables_cache; } void Item_cond::update_used_tables() { List_iterator_fast li(list); Item *item; used_tables_cache=0; const_item_cache=1; while ((item=li++)) { item->update_used_tables(); used_tables_cache|= item->used_tables(); const_item_cache&= item->const_item(); } } void Item_cond::print(String *str) { str->append('('); List_iterator_fast li(list); Item *item; if ((item=li++)) item->print(str); while ((item=li++)) { str->append(' '); str->append(func_name()); str->append(' '); item->print(str); } str->append(')'); } void Item_cond::neg_arguments(THD *thd) { List_iterator li(list); Item *item; while ((item= li++)) /* Apply not transformation to the arguments */ { Item *new_item= item->neg_transformer(thd); if (!new_item) { if (!(new_item= new Item_func_not(item))) return; // Fatal OEM error } VOID(li.replace(new_item)); } } /* Evaluation of AND(expr, expr, expr ...) NOTES: abort_if_null is set for AND expressions for which we don't care if the result is NULL or 0. This is set for: - WHERE clause - HAVING clause - IF(expression) RETURN VALUES 1 If all expressions are true 0 If all expressions are false or if we find a NULL expression and 'abort_on_null' is set. NULL if all expression are either 1 or NULL */ longlong Item_cond_and::val_int() { DBUG_ASSERT(fixed == 1); List_iterator_fast li(list); Item *item; null_value= 0; while ((item=li++)) { if (!item->val_bool()) { if (abort_on_null || !(null_value= item->null_value)) return 0; // return FALSE } } return null_value ? 0 : 1; } longlong Item_cond_or::val_int() { DBUG_ASSERT(fixed == 1); List_iterator_fast li(list); Item *item; null_value=0; while ((item=li++)) { if (item->val_bool()) { null_value=0; return 1; } if (item->null_value) null_value=1; } return 0; } /* Create an AND expression from two expressions SYNOPSIS and_expressions() a expression or NULL b expression. org_item Don't modify a if a == *org_item If a == NULL, org_item is set to point at b, to ensure that future calls will not modify b. NOTES This will not modify item pointed to by org_item or b The idea is that one can call this in a loop and create and 'and' over all items without modifying any of the original items. RETURN NULL Error Item */ Item *and_expressions(Item *a, Item *b, Item **org_item) { if (!a) return (*org_item= (Item*) b); if (a == *org_item) { Item_cond *res; if ((res= new Item_cond_and(a, (Item*) b))) { res->used_tables_cache= a->used_tables() | b->used_tables(); res->not_null_tables_cache= a->not_null_tables() | b->not_null_tables(); } return res; } if (((Item_cond_and*) a)->add((Item*) b)) return 0; ((Item_cond_and*) a)->used_tables_cache|= b->used_tables(); ((Item_cond_and*) a)->not_null_tables_cache|= b->not_null_tables(); return a; } longlong Item_func_isnull::val_int() { DBUG_ASSERT(fixed == 1); /* Handle optimization if the argument can't be null This has to be here because of the test in update_used_tables(). */ if (!used_tables_cache && !with_subselect) return cached_value; return args[0]->is_null() ? 1: 0; } longlong Item_is_not_null_test::val_int() { DBUG_ASSERT(fixed == 1); DBUG_ENTER("Item_is_not_null_test::val_int"); if (!used_tables_cache && !with_subselect) { owner->was_null|= (!cached_value); DBUG_PRINT("info", ("cached :%ld", (long) cached_value)); DBUG_RETURN(cached_value); } if (args[0]->is_null()) { DBUG_PRINT("info", ("null")); owner->was_null|= 1; DBUG_RETURN(0); } else DBUG_RETURN(1); } /* Optimize case of not_null_column IS NULL */ void Item_is_not_null_test::update_used_tables() { if (!args[0]->maybe_null) { used_tables_cache= 0; /* is always true */ cached_value= (longlong) 1; } else { args[0]->update_used_tables(); if (!(used_tables_cache=args[0]->used_tables()) && !with_subselect) { /* Remember if the value is always NULL or never NULL */ cached_value= (longlong) !args[0]->is_null(); } } } longlong Item_func_isnotnull::val_int() { DBUG_ASSERT(fixed == 1); return args[0]->is_null() ? 0 : 1; } void Item_func_isnotnull::print(String *str) { str->append('('); args[0]->print(str); str->append(STRING_WITH_LEN(" is not null)")); } longlong Item_func_like::val_int() { DBUG_ASSERT(fixed == 1); String* res = args[0]->val_str(&tmp_value1); if (args[0]->null_value) { null_value=1; return 0; } String* res2 = args[1]->val_str(&tmp_value2); if (args[1]->null_value) { null_value=1; return 0; } null_value=0; if (canDoTurboBM) return turboBM_matches(res->ptr(), res->length()) ? 1 : 0; return my_wildcmp(cmp.cmp_collation.collation, res->ptr(),res->ptr()+res->length(), res2->ptr(),res2->ptr()+res2->length(), escape,wild_one,wild_many) ? 0 : 1; } /* We can optimize a where if first character isn't a wildcard */ Item_func::optimize_type Item_func_like::select_optimize() const { if (args[1]->const_item()) { String* res2= args[1]->val_str((String *)&tmp_value2); if (!res2) return OPTIMIZE_NONE; if (*res2->ptr() != wild_many) { if (args[0]->result_type() != STRING_RESULT || *res2->ptr() != wild_one) return OPTIMIZE_OP; } } return OPTIMIZE_NONE; } bool Item_func_like::fix_fields(THD *thd, Item **ref) { DBUG_ASSERT(fixed == 0); if (Item_bool_func2::fix_fields(thd, ref) || escape_item->fix_fields(thd, &escape_item)) return TRUE; if (!escape_item->const_during_execution()) { my_error(ER_WRONG_ARGUMENTS,MYF(0),"ESCAPE"); return TRUE; } if (escape_item->const_item()) { /* If we are on execution stage */ String *escape_str= escape_item->val_str(&tmp_value1); if (escape_str) { if (escape_used_in_parsing && ( (((thd->variables.sql_mode & MODE_NO_BACKSLASH_ESCAPES) && escape_str->numchars() != 1) || escape_str->numchars() > 1))) { my_error(ER_WRONG_ARGUMENTS,MYF(0),"ESCAPE"); return TRUE; } if (use_mb(cmp.cmp_collation.collation)) { CHARSET_INFO *cs= escape_str->charset(); my_wc_t wc; int rc= cs->cset->mb_wc(cs, &wc, (const uchar*) escape_str->ptr(), (const uchar*) escape_str->ptr() + escape_str->length()); escape= (int) (rc > 0 ? wc : '\\'); } else { /* In the case of 8bit character set, we pass native code instead of Unicode code as "escape" argument. Convert to "cs" if charset of escape differs. */ CHARSET_INFO *cs= cmp.cmp_collation.collation; uint32 unused; if (escape_str->needs_conversion(escape_str->length(), escape_str->charset(), cs, &unused)) { char ch; uint errors; uint32 cnvlen= copy_and_convert(&ch, 1, cs, escape_str->ptr(), escape_str->length(), escape_str->charset(), &errors); escape= cnvlen ? ch : '\\'; } else escape= *(escape_str->ptr()); } } else escape= '\\'; /* We could also do boyer-more for non-const items, but as we would have to recompute the tables for each row it's not worth it. */ if (args[1]->const_item() && !use_strnxfrm(collation.collation) && !(specialflag & SPECIAL_NO_NEW_FUNC)) { String* res2 = args[1]->val_str(&tmp_value2); if (!res2) return FALSE; // Null argument const size_t len = res2->length(); const char* first = res2->ptr(); const char* last = first + len - 1; /* len must be > 2 ('%pattern%') heuristic: only do TurboBM for pattern_len > 2 */ if (len > MIN_TURBOBM_PATTERN_LEN + 2 && *first == wild_many && *last == wild_many) { const char* tmp = first + 1; for (; *tmp != wild_many && *tmp != wild_one && *tmp != escape; tmp++) ; canDoTurboBM = (tmp == last) && !use_mb(args[0]->collation.collation); } if (canDoTurboBM) { pattern = first + 1; pattern_len = (int) len - 2; DBUG_PRINT("info", ("Initializing pattern: '%s'", first)); int *suff = (int*) thd->alloc((int) (sizeof(int)* ((pattern_len + 1)*2+ alphabet_size))); bmGs = suff + pattern_len + 1; bmBc = bmGs + pattern_len + 1; turboBM_compute_good_suffix_shifts(suff); turboBM_compute_bad_character_shifts(); DBUG_PRINT("info",("done")); } } } return FALSE; } void Item_func_like::cleanup() { canDoTurboBM= FALSE; Item_bool_func2::cleanup(); } #ifdef USE_REGEX bool Item_func_regex::fix_fields(THD *thd, Item **ref) { DBUG_ASSERT(fixed == 0); if ((!args[0]->fixed && args[0]->fix_fields(thd, args)) || args[0]->check_cols(1) || (!args[1]->fixed && args[1]->fix_fields(thd, args + 1)) || args[1]->check_cols(1)) return TRUE; /* purecov: inspected */ with_sum_func=args[0]->with_sum_func || args[1]->with_sum_func; max_length= 1; decimals= 0; if (agg_arg_charsets(cmp_collation, args, 2, MY_COLL_CMP_CONV, 1)) return TRUE; used_tables_cache=args[0]->used_tables() | args[1]->used_tables(); not_null_tables_cache= (args[0]->not_null_tables() | args[1]->not_null_tables()); const_item_cache=args[0]->const_item() && args[1]->const_item(); if (!regex_compiled && args[1]->const_item()) { char buff[MAX_FIELD_WIDTH]; String tmp(buff,sizeof(buff),&my_charset_bin); String *res=args[1]->val_str(&tmp); if (args[1]->null_value) { // Will always return NULL maybe_null=1; return FALSE; } int error; if ((error= my_regcomp(&preg,res->c_ptr(), ((cmp_collation.collation->state & (MY_CS_BINSORT | MY_CS_CSSORT)) ? REG_EXTENDED | REG_NOSUB : REG_EXTENDED | REG_NOSUB | REG_ICASE), cmp_collation.collation))) { (void) my_regerror(error,&preg,buff,sizeof(buff)); my_error(ER_REGEXP_ERROR, MYF(0), buff); return TRUE; } regex_compiled=regex_is_const=1; maybe_null=args[0]->maybe_null; } else maybe_null=1; fixed= 1; return FALSE; } longlong Item_func_regex::val_int() { DBUG_ASSERT(fixed == 1); char buff[MAX_FIELD_WIDTH]; String *res, tmp(buff,sizeof(buff),&my_charset_bin); res=args[0]->val_str(&tmp); if (args[0]->null_value) { null_value=1; return 0; } if (!regex_is_const) { char buff2[MAX_FIELD_WIDTH]; String *res2, tmp2(buff2,sizeof(buff2),&my_charset_bin); res2= args[1]->val_str(&tmp2); if (args[1]->null_value) { null_value=1; return 0; } if (!regex_compiled || stringcmp(res2,&prev_regexp)) { prev_regexp.copy(*res2); if (regex_compiled) { my_regfree(&preg); regex_compiled=0; } if (my_regcomp(&preg,res2->c_ptr_safe(), ((cmp_collation.collation->state & (MY_CS_BINSORT | MY_CS_CSSORT)) ? REG_EXTENDED | REG_NOSUB : REG_EXTENDED | REG_NOSUB | REG_ICASE), cmp_collation.collation)) { null_value=1; return 0; } regex_compiled=1; } } null_value=0; return my_regexec(&preg,res->c_ptr_safe(),0,(my_regmatch_t*) 0,0) ? 0 : 1; } void Item_func_regex::cleanup() { DBUG_ENTER("Item_func_regex::cleanup"); Item_bool_func::cleanup(); if (regex_compiled) { my_regfree(&preg); regex_compiled=0; } DBUG_VOID_RETURN; } #endif /* USE_REGEX */ #ifdef LIKE_CMP_TOUPPER #define likeconv(cs,A) (uchar) (cs)->toupper(A) #else #define likeconv(cs,A) (uchar) (cs)->sort_order[(uchar) (A)] #endif /********************************************************************** turboBM_compute_suffixes() Precomputation dependent only on pattern_len. **********************************************************************/ void Item_func_like::turboBM_compute_suffixes(int *suff) { const int plm1 = pattern_len - 1; int f = 0; int g = plm1; int *const splm1 = suff + plm1; CHARSET_INFO *cs= cmp.cmp_collation.collation; *splm1 = pattern_len; if (!cs->sort_order) { int i; for (i = pattern_len - 2; i >= 0; i--) { int tmp = *(splm1 + i - f); if (g < i && tmp < i - g) suff[i] = tmp; else { if (i < g) g = i; // g = min(i, g) f = i; while (g >= 0 && pattern[g] == pattern[g + plm1 - f]) g--; suff[i] = f - g; } } } else { int i; for (i = pattern_len - 2; 0 <= i; --i) { int tmp = *(splm1 + i - f); if (g < i && tmp < i - g) suff[i] = tmp; else { if (i < g) g = i; // g = min(i, g) f = i; while (g >= 0 && likeconv(cs, pattern[g]) == likeconv(cs, pattern[g + plm1 - f])) g--; suff[i] = f - g; } } } } /********************************************************************** turboBM_compute_good_suffix_shifts() Precomputation dependent only on pattern_len. **********************************************************************/ void Item_func_like::turboBM_compute_good_suffix_shifts(int *suff) { turboBM_compute_suffixes(suff); int *end = bmGs + pattern_len; int *k; for (k = bmGs; k < end; k++) *k = pattern_len; int tmp; int i; int j = 0; const int plm1 = pattern_len - 1; for (i = plm1; i > -1; i--) { if (suff[i] == i + 1) { for (tmp = plm1 - i; j < tmp; j++) { int *tmp2 = bmGs + j; if (*tmp2 == pattern_len) *tmp2 = tmp; } } } int *tmp2; for (tmp = plm1 - i; j < tmp; j++) { tmp2 = bmGs + j; if (*tmp2 == pattern_len) *tmp2 = tmp; } tmp2 = bmGs + plm1; for (i = 0; i <= pattern_len - 2; i++) *(tmp2 - suff[i]) = plm1 - i; } /********************************************************************** turboBM_compute_bad_character_shifts() Precomputation dependent on pattern_len. **********************************************************************/ void Item_func_like::turboBM_compute_bad_character_shifts() { int *i; int *end = bmBc + alphabet_size; int j; const int plm1 = pattern_len - 1; CHARSET_INFO *cs= cmp.cmp_collation.collation; for (i = bmBc; i < end; i++) *i = pattern_len; if (!cs->sort_order) { for (j = 0; j < plm1; j++) bmBc[(uint) (uchar) pattern[j]] = plm1 - j; } else { for (j = 0; j < plm1; j++) bmBc[(uint) likeconv(cs,pattern[j])] = plm1 - j; } } /********************************************************************** turboBM_matches() Search for pattern in text, returns true/false for match/no match **********************************************************************/ bool Item_func_like::turboBM_matches(const char* text, int text_len) const { register int bcShift; register int turboShift; int shift = pattern_len; int j = 0; int u = 0; CHARSET_INFO *cs= cmp.cmp_collation.collation; const int plm1= pattern_len - 1; const int tlmpl= text_len - pattern_len; /* Searching */ if (!cs->sort_order) { while (j <= tlmpl) { register int i= plm1; while (i >= 0 && pattern[i] == text[i + j]) { i--; if (i == plm1 - shift) i-= u; } if (i < 0) return 1; register const int v = plm1 - i; turboShift = u - v; bcShift = bmBc[(uint) (uchar) text[i + j]] - plm1 + i; shift = max(turboShift, bcShift); shift = max(shift, bmGs[i]); if (shift == bmGs[i]) u = min(pattern_len - shift, v); else { if (turboShift < bcShift) shift = max(shift, u + 1); u = 0; } j+= shift; } return 0; } else { while (j <= tlmpl) { register int i = plm1; while (i >= 0 && likeconv(cs,pattern[i]) == likeconv(cs,text[i + j])) { i--; if (i == plm1 - shift) i-= u; } if (i < 0) return 1; register const int v = plm1 - i; turboShift = u - v; bcShift = bmBc[(uint) likeconv(cs, text[i + j])] - plm1 + i; shift = max(turboShift, bcShift); shift = max(shift, bmGs[i]); if (shift == bmGs[i]) u = min(pattern_len - shift, v); else { if (turboShift < bcShift) shift = max(shift, u + 1); u = 0; } j+= shift; } return 0; } } /* Make a logical XOR of the arguments. SYNOPSIS val_int() DESCRIPTION If either operator is NULL, return NULL. NOTE As we don't do any index optimization on XOR this is not going to be very fast to use. TODO (low priority) Change this to be optimized as: A XOR B -> (A) == 1 AND (B) <> 1) OR (A <> 1 AND (B) == 1) To be able to do this, we would however first have to extend the MySQL range optimizer to handle OR better. */ longlong Item_cond_xor::val_int() { DBUG_ASSERT(fixed == 1); List_iterator li(list); Item *item; int result=0; null_value=0; while ((item=li++)) { result^= (item->val_int() != 0); if (item->null_value) { null_value=1; return 0; } } return (longlong) result; } /* Apply NOT transformation to the item and return a new one. SYNOPSIS neg_transformer() thd thread handler DESCRIPTION Transform the item using next rules: a AND b AND ... -> NOT(a) OR NOT(b) OR ... a OR b OR ... -> NOT(a) AND NOT(b) AND ... NOT(a) -> a a = b -> a != b a != b -> a = b a < b -> a >= b a >= b -> a < b a > b -> a <= b a <= b -> a > b IS NULL(a) -> IS NOT NULL(a) IS NOT NULL(a) -> IS NULL(a) RETURN New item or NULL if we cannot apply NOT transformation (see Item::neg_transformer()). */ Item *Item_func_not::neg_transformer(THD *thd) /* NOT(x) -> x */ { return args[0]; } Item *Item_bool_rowready_func2::neg_transformer(THD *thd) { Item *item= negated_item(); return item; } /* a IS NULL -> a IS NOT NULL */ Item *Item_func_isnull::neg_transformer(THD *thd) { Item *item= new Item_func_isnotnull(args[0]); return item; } /* a IS NOT NULL -> a IS NULL */ Item *Item_func_isnotnull::neg_transformer(THD *thd) { Item *item= new Item_func_isnull(args[0]); return item; } Item *Item_cond_and::neg_transformer(THD *thd) /* NOT(a AND b AND ...) -> */ /* NOT a OR NOT b OR ... */ { neg_arguments(thd); Item *item= new Item_cond_or(list); return item; } Item *Item_cond_or::neg_transformer(THD *thd) /* NOT(a OR b OR ...) -> */ /* NOT a AND NOT b AND ... */ { neg_arguments(thd); Item *item= new Item_cond_and(list); return item; } Item *Item_func_nop_all::neg_transformer(THD *thd) { /* "NOT (e $cmp$ ANY (SELECT ...)) -> e $rev_cmp$" ALL (SELECT ...) */ Item_func_not_all *new_item= new Item_func_not_all(args[0]); Item_allany_subselect *allany= (Item_allany_subselect*)args[0]; allany->func= allany->func_creator(FALSE); allany->all= !allany->all; allany->upper_item= new_item; return new_item; } Item *Item_func_not_all::neg_transformer(THD *thd) { /* "NOT (e $cmp$ ALL (SELECT ...)) -> e $rev_cmp$" ANY (SELECT ...) */ Item_func_nop_all *new_item= new Item_func_nop_all(args[0]); Item_allany_subselect *allany= (Item_allany_subselect*)args[0]; allany->all= !allany->all; allany->func= allany->func_creator(TRUE); allany->upper_item= new_item; return new_item; } Item *Item_func_eq::negated_item() /* a = b -> a != b */ { return new Item_func_ne(args[0], args[1]); } Item *Item_func_ne::negated_item() /* a != b -> a = b */ { return new Item_func_eq(args[0], args[1]); } Item *Item_func_lt::negated_item() /* a < b -> a >= b */ { return new Item_func_ge(args[0], args[1]); } Item *Item_func_ge::negated_item() /* a >= b -> a < b */ { return new Item_func_lt(args[0], args[1]); } Item *Item_func_gt::negated_item() /* a > b -> a <= b */ { return new Item_func_le(args[0], args[1]); } Item *Item_func_le::negated_item() /* a <= b -> a > b */ { return new Item_func_gt(args[0], args[1]); } // just fake method, should never be called Item *Item_bool_rowready_func2::negated_item() { DBUG_ASSERT(0); return 0; } Item_equal::Item_equal(Item_field *f1, Item_field *f2) : Item_bool_func(), const_item(0), eval_item(0), cond_false(0) { const_item_cache= 0; fields.push_back(f1); fields.push_back(f2); } Item_equal::Item_equal(Item *c, Item_field *f) : Item_bool_func(), eval_item(0), cond_false(0) { const_item_cache= 0; fields.push_back(f); const_item= c; } Item_equal::Item_equal(Item_equal *item_equal) : Item_bool_func(), eval_item(0), cond_false(0) { const_item_cache= 0; List_iterator_fast li(item_equal->fields); Item_field *item; while ((item= li++)) { fields.push_back(item); } const_item= item_equal->const_item; cond_false= item_equal->cond_false; } void Item_equal::add(Item *c) { if (cond_false) return; if (!const_item) { const_item= c; return; } Item_func_eq *func= new Item_func_eq(c, const_item); func->set_cmp_func(); func->quick_fix_field(); if ((cond_false= !func->val_int())) const_item_cache= 1; } void Item_equal::add(Item_field *f) { fields.push_back(f); } uint Item_equal::members() { return fields.elements; } /* Check whether a field is referred in the multiple equality SYNOPSIS contains() field field whose occurrence is to be checked DESCRIPTION The function checks whether field is occurred in the Item_equal object RETURN VALUES 1 if nultiple equality contains a reference to field 0 otherwise */ bool Item_equal::contains(Field *field) { List_iterator_fast it(fields); Item_field *item; while ((item= it++)) { if (field->eq(item->field)) return 1; } return 0; } /* Join members of another Item_equal object SYNOPSIS merge() item multiple equality whose members are to be joined DESCRIPTION The function actually merges two multiple equalities. After this operation the Item_equal object additionally contains the field items of another item of the type Item_equal. If the optional constant items are not equal the cond_false flag is set to 1. RETURN VALUES none */ void Item_equal::merge(Item_equal *item) { fields.concat(&item->fields); Item *c= item->const_item; if (c) { /* The flag cond_false will be set to 1 after this, if the multiple equality already contains a constant and its value is not equal to the value of c. */ add(c); } cond_false|= item->cond_false; } /* Order field items in multiple equality according to a sorting criteria SYNOPSIS sort() cmp function to compare field item arg context extra parameter for the cmp function DESCRIPTION The function perform ordering of the field items in the Item_equal object according to the criteria determined by the cmp callback parameter. If cmp(item_field1,item_field2,arg)<0 than item_field1 must be placed after item_fiel2. IMPLEMENTATION The function sorts field items by the exchange sort algorithm. The list of field items is looked through and whenever two neighboring members follow in a wrong order they are swapped. This is performed again and again until we get all members in a right order. RETURN VALUES None */ void Item_equal::sort(Item_field_cmpfunc cmp, void *arg) { bool swap; List_iterator it(fields); do { Item_field *item1= it++; Item_field **ref1= it.ref(); Item_field *item2; swap= FALSE; while ((item2= it++)) { Item_field **ref2= it.ref(); if (cmp(item1, item2, arg) < 0) { Item_field *item= *ref1; *ref1= *ref2; *ref2= item; swap= TRUE; } else { item1= item2; ref1= ref2; } } it.rewind(); } while (swap); } /* Check appearance of new constant items in the multiple equality object SYNOPSIS update_const() DESCRIPTION The function checks appearance of new constant items among the members of multiple equalities. Each new constant item is compared with the designated constant item if there is any in the multiple equality. If there is none the first new constant item becomes designated. RETURN VALUES none */ void Item_equal::update_const() { List_iterator it(fields); Item *item; while ((item= it++)) { if (item->const_item()) { it.remove(); add(item); } } } bool Item_equal::fix_fields(THD *thd, Item **ref) { List_iterator_fast li(fields); Item *item; not_null_tables_cache= used_tables_cache= 0; const_item_cache= 0; while ((item= li++)) { table_map tmp_table_map; used_tables_cache|= item->used_tables(); tmp_table_map= item->not_null_tables(); not_null_tables_cache|= tmp_table_map; if (item->maybe_null) maybe_null=1; } fix_length_and_dec(); fixed= 1; return 0; } void Item_equal::update_used_tables() { List_iterator_fast li(fields); Item *item; not_null_tables_cache= used_tables_cache= 0; if ((const_item_cache= cond_false)) return; while ((item=li++)) { item->update_used_tables(); used_tables_cache|= item->used_tables(); const_item_cache&= item->const_item(); } } longlong Item_equal::val_int() { Item_field *item_field; if (cond_false) return 0; List_iterator_fast it(fields); Item *item= const_item ? const_item : it++; if ((null_value= item->null_value)) return 0; eval_item->store_value(item); while ((item_field= it++)) { /* Skip fields of non-const tables. They haven't been read yet */ if (item_field->field->table->const_table) { if ((null_value= item_field->null_value) || eval_item->cmp(item_field)) return 0; } } return 1; } void Item_equal::fix_length_and_dec() { Item *item= get_first(); eval_item= cmp_item::get_comparator(item->result_type(), item->collation.collation); } bool Item_equal::walk(Item_processor processor, byte *arg) { List_iterator_fast it(fields); Item *item; while ((item= it++)) if (item->walk(processor, arg)) return 1; return Item_func::walk(processor, arg); } Item *Item_equal::transform(Item_transformer transformer, byte *arg) { DBUG_ASSERT(!current_thd->is_stmt_prepare()); List_iterator it(fields); Item *item; while ((item= it++)) { Item *new_item= item->transform(transformer, arg); if (!new_item) return 0; /* THD::change_item_tree() should be called only if the tree was really transformed, i.e. when a new item has been created. Otherwise we'll be allocating a lot of unnecessary memory for change records at each execution. */ if (new_item != item) current_thd->change_item_tree((Item **) it.ref(), new_item); } return Item_func::transform(transformer, arg); } void Item_equal::print(String *str) { str->append(func_name()); str->append('('); List_iterator_fast it(fields); Item *item; if (const_item) const_item->print(str); else { item= it++; item->print(str); } while ((item= it++)) { str->append(','); str->append(' '); item->print(str); } str->append(')'); }