diff options
Diffstat (limited to 'sql/item.h')
| -rw-r--r-- | sql/item.h | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/sql/item.h b/sql/item.h index 2219153616b..b98389bc8d4 100644 --- a/sql/item.h +++ b/sql/item.h @@ -2622,16 +2622,23 @@ class Item_cache: public Item protected: Item *example; table_map used_table_map; + /* + Field that this object will get value from. This is set/used by + index-based subquery engines to detect and remove the equality injected + by IN->EXISTS transformation. + For all other uses of Item_cache, cached_field doesn't matter. + */ + Field *cached_field; enum enum_field_types cached_field_type; public: Item_cache(): - example(0), used_table_map(0), cached_field_type(MYSQL_TYPE_STRING) + example(0), used_table_map(0), cached_field(0), cached_field_type(MYSQL_TYPE_STRING) { fixed= 1; null_value= 1; } Item_cache(enum_field_types field_type_arg): - example(0), used_table_map(0), cached_field_type(field_type_arg) + example(0), used_table_map(0), cached_field(0), cached_field_type(field_type_arg) { fixed= 1; null_value= 1; @@ -2647,6 +2654,8 @@ public: decimals= item->decimals; collation.set(item->collation); unsigned_flag= item->unsigned_flag; + if (item->type() == FIELD_ITEM) + cached_field= ((Item_field *)item)->field; return 0; }; virtual void store(Item *)= 0; @@ -2658,6 +2667,14 @@ public: // to prevent drop fixed flag (no need parent cleanup call) void cleanup() {} void print(String *str); + bool eq_def(Field *field) + { + return cached_field ? cached_field->eq_def (field) : FALSE; + } + bool eq(const Item *item, bool binary_cmp) const + { + return this == item; + } }; |