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

Bug#23800: Outer fields in correlated subqueries is used in a temporary table

Browse Source 
created for sorting.

Any outer reference in a subquery was represented by an Item_field object.
If the outer select employs a temporary table all such fields should be
replaced with fields from that temporary table in order to point to the 
actual data. This replacement wasn't done and that resulted in a wrong
subquery evaluation and a wrong result of the whole query.

Now any outer field is represented by two objects - Item_field placed in the
outer select and Item_outer_ref in the subquery. Item_field object is
processed as a normal field and the reference to it is saved in the
ref_pointer_array. Thus the Item_outer_ref is always references the correct
field. The original field is substituted for a reference in the
Item_field::fix_outer_field() function.

New function called fix_inner_refs() is added to fix fields referenced from
inner selects and to fix references (Item_ref objects) to these fields.

The new Item_outer_ref class is a descendant of the Item_direct_ref class.
It additionally stores a reference to the original field and designed to
behave more like a field.
This commit is contained in:
evgen@moonbone.local
2007-02-21 23:00:32 +03:00
parent 674868dabf
commit 9a233742b8
11 changed files with 290 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
sql/sql_update.cc
View File

@ -134,6 +134,7 @@ int mysql_update(THD *thd,
READ_RECORD info;
SELECT_LEX *select_lex= &thd->lex->select_lex;
bool need_reopen;
List<Item> all_fields;
DBUG_ENTER("mysql_update");
LINT_INIT(timestamp_query_id);
@ -226,6 +227,10 @@ int mysql_update(THD *thd,
DBUG_RETURN(1); /* purecov: inspected */
}
if (select_lex->inner_refs_list.elements &&
fix_inner_refs(thd, all_fields, select_lex, select_lex->ref_pointer_array))
DBUG_RETURN(-1);
if (conds)
{
Item::cond_result cond_value;