diff options
Diffstat (limited to 'sql/sql_select.cc')
| -rw-r--r-- | sql/sql_select.cc | 30 |
1 files changed, 14 insertions, 16 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index dbf8ea62e88..8d415419336 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -2874,19 +2874,6 @@ add_key_fields(KEY_FIELD **key_fields,uint *and_level, if (cond->type() != Item::FUNC_ITEM) return; Item_func *cond_func= (Item_func*) cond; - if (cond_func->functype() == Item_func::NOT_FUNC) - { - Item *item= cond_func->arguments()[0]; - /* - At this moment all NOT before simple comparison predicates - are eliminated. NOT IN and NOT BETWEEN are treated similar - IN and BETWEEN respectively. - */ - if (item->type() == Item::FUNC_ITEM && - ((Item_func *) item)->select_optimize() == Item_func::OPTIMIZE_KEY) - add_key_fields(key_fields,and_level,item,usable_tables); - return; - } switch (cond_func->select_optimize()) { case Item_func::OPTIMIZE_NONE: break; @@ -13087,6 +13074,8 @@ void free_underlaid_joins(THD *thd, SELECT_LEX *select) The function replaces occurrences of group by fields in expr by ref objects for these fields unless they are under aggregate functions. + The function also corrects value of the the maybe_null attribute + for the items of all subexpressions containing group by fields. IMPLEMENTATION The function recursively traverses the tree of the expr expression, @@ -13097,6 +13086,9 @@ void free_underlaid_joins(THD *thd, SELECT_LEX *select) This substitution is needed GROUP BY queries with ROLLUP if SELECT list contains expressions over group by attributes. + TODO: Some functions are not null-preserving. For those functions + updating of the maybe_null attribute is an overkill. + EXAMPLES SELECT a+1 FROM t1 GROUP BY a WITH ROLLUP SELECT SUM(a)+a FROM t1 GROUP BY a WITH ROLLUP @@ -13118,6 +13110,7 @@ static bool change_group_ref(THD *thd, Item_func *expr, ORDER *group_list, arg != arg_end; arg++) { Item *item= *arg; + bool arg_changed= FALSE; if (item->type() == Item::FIELD_ITEM || item->type() == Item::REF_ITEM) { ORDER *group_tmp; @@ -13130,15 +13123,20 @@ static bool change_group_ref(THD *thd, Item_func *expr, ORDER *group_list, item->name))) return 1; // fatal_error is set thd->change_item_tree(arg, new_item); - *changed= TRUE; + arg_changed= TRUE; } } } else if (item->type() == Item::FUNC_ITEM) { - if (change_group_ref(thd, (Item_func *) item, group_list, changed)) + if (change_group_ref(thd, (Item_func *) item, group_list, &arg_changed)) return 1; } + if (arg_changed) + { + expr->maybe_null= 1; + *changed= TRUE; + } } } return 0; @@ -13201,7 +13199,7 @@ bool JOIN::rollup_init() } if (item->type() == Item::FUNC_ITEM) { - bool changed= 0; + bool changed= FALSE; if (change_group_ref(thd, (Item_func *) item, group_list, &changed)) return 1; /* |