diff options
Diffstat (limited to 'sql/item_cmpfunc.h')
| -rw-r--r-- | sql/item_cmpfunc.h | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h index c691797e2c5..7774663bd57 100644 --- a/sql/item_cmpfunc.h +++ b/sql/item_cmpfunc.h @@ -1075,6 +1075,7 @@ class Item_func_nullif :public Item_func_hybrid_field_type if (arg_count == 3 && args[0] != args[2]) args[0]= args[2]; } + Item *m_arg0; public: /* Here we pass three arguments to the parent constructor, as NULLIF @@ -1086,8 +1087,14 @@ public: */ Item_func_nullif(THD *thd, Item *a, Item *b): Item_func_hybrid_field_type(thd, a, b, a), - m_cache(NULL) + m_cache(NULL), + m_arg0(NULL) { arg_count--; } + void cleanup() + { + Item_func_hybrid_field_type::cleanup(); + arg_count= 2; // See the comment to the constructor + } bool date_op(MYSQL_TIME *ltime, uint fuzzydate); double real_op(); longlong int_op(); @@ -1772,10 +1779,26 @@ public: const char *func_name() const { return "isnull"; } void print(String *str, enum_query_type query_type); enum precedence precedence() const { return CMP_PRECEDENCE; } + + bool arg_is_datetime_notnull_field() + { + Item **args= arguments(); + if (args[0]->type() == Item::FIELD_ITEM) + { + Field *field=((Item_field*) args[0])->field; + + if (((field->type() == MYSQL_TYPE_DATE) || + (field->type() == MYSQL_TYPE_DATETIME)) && + (field->flags & NOT_NULL_FLAG)) + return true; + } + return false; + } + /* Optimize case of not_null_column IS NULL */ virtual void update_used_tables() { - if (!args[0]->maybe_null) + if (!args[0]->maybe_null && !arg_is_datetime_notnull_field()) { used_tables_cache= 0; /* is always false */ const_item_cache= 1; @@ -2695,4 +2718,3 @@ extern Ge_creator ge_creator; extern Le_creator le_creator; #endif /* ITEM_CMPFUNC_INCLUDED */ - |