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Manual merge

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igor@rurik.mysql.com
2005-09-08 13:44:36 -07:00
parent 13d8179157 3b76329f78
commit bcae525685
7 changed files with 79 additions and 43 deletions
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17
sql/sql_select.cc
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@ -13043,6 +13043,8 @@ 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,
@ -13053,6 +13055,9 @@ 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
@ -13074,6 +13079,7 @@ 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;
@ -13086,15 +13092,20 @@ 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;
@ -13157,7 +13168,7 @@ 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;
/*