diff options
Diffstat (limited to 'sql/item_cmpfunc.cc')
| -rw-r--r-- | sql/item_cmpfunc.cc | 53 |
1 files changed, 32 insertions, 21 deletions
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc index c560e1de974..09c2bdc593a 100644 --- a/sql/item_cmpfunc.cc +++ b/sql/item_cmpfunc.cc @@ -25,9 +25,9 @@ #include <m_ctype.h> /* -** Test functions -** These returns 0LL if false and 1LL if true and null if some arg is null -** 'AND' and 'OR' never return null + Test functions + These returns 0LL if false and 1LL if true and null if some arg is null + 'AND' and 'OR' never return null */ longlong Item_func_not::val_int() @@ -45,8 +45,8 @@ static bool convert_constant_item(Field *field, Item **item) (*item)->save_in_field(field); if (!((*item)->null_value)) { - Item *tmp=new Item_int(field->val_int()); - if ((tmp)) + Item *tmp=new Item_int_with_ref(field->val_int(), *item); + if (tmp) *item=tmp; return 1; } @@ -59,8 +59,10 @@ void Item_bool_func2::fix_length_and_dec() { max_length=1; - /* As some compare functions are generated after sql_yacc, - we have to check for out of memory conditons here */ + /* + As some compare functions are generated after sql_yacc, + we have to check for out of memory conditons here + */ if (!args[0] || !args[1]) return; // Make a special case of compare with fields to get nicer DATE comparisons @@ -336,8 +338,10 @@ void Item_func_between::fix_length_and_dec() { max_length=1; - /* As some compare functions are generated after sql_yacc, - we have to check for out of memory conditons here */ + /* + As some compare functions are generated after sql_yacc, + we have to check for out of memory conditons here + */ if (!args[0] || !args[1] || !args[2]) return; cmp_type=args[0]->result_type(); @@ -389,7 +393,7 @@ longlong Item_func_between::val_int() { longlong value=args[0]->val_int(),a,b; if ((null_value=args[0]->null_value)) - return 0; /* purecov: inspected */ + return 0; /* purecov: inspected */ a=args[1]->val_int(); b=args[2]->val_int(); if (!args[1]->null_value && !args[2]->null_value) @@ -409,7 +413,7 @@ longlong Item_func_between::val_int() { double value=args[0]->val(),a,b; if ((null_value=args[0]->null_value)) - return 0; /* purecov: inspected */ + return 0; /* purecov: inspected */ a=args[1]->val(); b=args[2]->val(); if (!args[1]->null_value && !args[2]->null_value) @@ -594,11 +598,10 @@ Item_func_nullif::val_str(String *str) } /* -** CASE expression + CASE expression + Return the matching ITEM or NULL if all compares (including else) failed */ -/* 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; @@ -786,7 +789,7 @@ void Item_func_case::print(String *str) } /* -** Coalesce - return first not NULL argument. + Coalesce - return first not NULL argument. */ String *Item_func_coalesce::val_str(String *str) @@ -842,7 +845,7 @@ void Item_func_coalesce::fix_length_and_dec() } /**************************************************************************** -** classes and function for the IN operator + Classes and function for the IN operator ****************************************************************************/ static int cmp_longlong(longlong *a,longlong *b) @@ -915,7 +918,7 @@ byte *in_longlong::get_value(Item *item) { tmp=item->val_int(); if (item->null_value) - return 0; /* purecov: inspected */ + return 0; /* purecov: inspected */ return (byte*) &tmp; } @@ -933,7 +936,7 @@ byte *in_double::get_value(Item *item) { tmp=item->val(); if (item->null_value) - return 0; /* purecov: inspected */ + return 0; /* purecov: inspected */ return (byte*) &tmp; } @@ -1171,9 +1174,11 @@ longlong Item_cond_and::val_int() { if (item->val_int() == 0) { - /* TODO: In case of NULL, ANSI would require us to continue evaluation - until we get a FALSE value or run out of values; This would - require a lot of unnecessary evaluation, which we skip for now */ + /* + TODO: In case of NULL, ANSI would require us to continue evaluation + until we get a FALSE value or run out of values; This would + require a lot of unnecessary evaluation, which we skip for now + */ null_value=item->null_value; return 0; } @@ -1202,6 +1207,12 @@ longlong Item_cond_or::val_int() longlong Item_func_isnull::val_int() { + /* + 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) + return cached_value; return args[0]->is_null() ? 1: 0; } |