database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-08-01 03:47:19 +03:00
Code Activity

Automerge.

Browse Source
This commit is contained in:
Ramil Kalimullin
2010-06-24 12:34:05 +04:00
parent 149d305484 0d7eb317b5
commit 389c68a8d4
3 changed files with 38 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
sql/sql_select.cc
View File

@ -586,13 +586,21 @@ JOIN::prepare(Item ***rref_pointer_array,
{
Item *item= *ord->item;
/*
Disregard sort order if there's only "{VAR}CHAR(0) NOT NULL" fields
there. Such fields don't contain any data to sort.
Disregard sort order if there's only
zero length NOT NULL fields (e.g. {VAR}CHAR(0) NOT NULL") or
zero length NOT NULL string functions there.
Such tuples don't contain any data to sort.
*/
if (!real_order &&
(item->type() != Item::FIELD_ITEM ||
((Item_field *) item)->field->maybe_null() ||
((Item_field *) item)->field->sort_length()))
/* Not a zero length NOT NULL field */
((item->type() != Item::FIELD_ITEM ||
((Item_field *) item)->field->maybe_null() ||
((Item_field *) item)->field->sort_length()) &&
/* AND not a zero length NOT NULL string function. */
(item->type() != Item::FUNC_ITEM ||
item->maybe_null ||
item->result_type() != STRING_RESULT ||
item->max_length)))
real_order= TRUE;
if (item->with_sum_func && item->type() != Item::SUM_FUNC_ITEM)