database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2026-01-06 05:22:24 +03:00
Code Activity

Bug#47669 Query showed by EXPLAIN EXTENDED gives different result from original query

Browse Source 
Item_field::print method does not take into
account fields whose values may be null.
The fix is to print 'NULL' if field value is null.
This commit is contained in:
Sergey Glukhov
2010-02-26 17:40:01 +04:00
parent 3fcb25d806
commit 5d9a74f22d
8 changed files with 48 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
mysql-test/r/select.result
View File

@@ -4050,10 +4050,10 @@ join_0.c1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
Warnings:
Note 1003 select '0' AS `c1` from `test`.`t1` `join_0` join `test`.`t1` `join_1` join `test`.`t1` `join_2` join `test`.`t1` `join_3` join `test`.`t1` `join_4` join `test`.`t1` `join_5` join `test`.`t1` `join_6` join `test`.`t1` `join_7` where 0 group by '0','0','0','0','0'
Note 1003 select NULL AS `c1` from `test`.`t1` `join_0` join `test`.`t1` `join_1` join `test`.`t1` `join_2` join `test`.`t1` `join_3` join `test`.`t1` `join_4` join `test`.`t1` `join_5` join `test`.`t1` `join_6` join `test`.`t1` `join_7` where 0 group by NULL,NULL,NULL,NULL,NULL
SHOW WARNINGS;
Level Code Message
Note 1003 select '0' AS `c1` from `test`.`t1` `join_0` join `test`.`t1` `join_1` join `test`.`t1` `join_2` join `test`.`t1` `join_3` join `test`.`t1` `join_4` join `test`.`t1` `join_5` join `test`.`t1` `join_6` join `test`.`t1` `join_7` where 0 group by '0','0','0','0','0'
Note 1003 select NULL AS `c1` from `test`.`t1` `join_0` join `test`.`t1` `join_1` join `test`.`t1` `join_2` join `test`.`t1` `join_3` join `test`.`t1` `join_4` join `test`.`t1` `join_5` join `test`.`t1` `join_6` join `test`.`t1` `join_7` where 0 group by NULL,NULL,NULL,NULL,NULL
DROP TABLE t1;
SELECT 1 AS ` `;
@@ -4648,17 +4648,17 @@ EXPLAIN EXTENDED SELECT * FROM t1 WHERE (a=a AND b=b AND c=c) OR b > 20;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 system NULL NULL NULL NULL 0 0.00 const row not found
Warnings:
Note 1003 select '0' AS `a`,'0' AS `b`,'0' AS `c` from `test`.`t1` where 1
Note 1003 select NULL AS `a`,NULL AS `b`,NULL AS `c` from `test`.`t1` where 1
EXPLAIN EXTENDED SELECT * FROM t1 WHERE (a=a AND a=a AND b=b) OR b > 20;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 system NULL NULL NULL NULL 0 0.00 const row not found
Warnings:
Note 1003 select '0' AS `a`,'0' AS `b`,'0' AS `c` from `test`.`t1` where 1
Note 1003 select NULL AS `a`,NULL AS `b`,NULL AS `c` from `test`.`t1` where 1
EXPLAIN EXTENDED SELECT * FROM t1 WHERE (a=a AND b=b AND a=a) OR b > 20;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 system NULL NULL NULL NULL 0 0.00 const row not found
Warnings:
Note 1003 select '0' AS `a`,'0' AS `b`,'0' AS `c` from `test`.`t1` where 1
Note 1003 select NULL AS `a`,NULL AS `b`,NULL AS `c` from `test`.`t1` where 1
DROP TABLE t1;
#
# Bug#45266: Uninitialized variable lead to an empty result.