Bug #20021 show command with like

• Submitted: 23 May 2006 9:22
• Modified: 23 May 2006 11:53
• Reporter: mike rahm
• Status: Not a Bug
• Category: MySQL Server
• Severity: S3 (Non-critical)
• Version: 5.0
• OS: Windows (win xp)
• CPU Architecture: Any

[23 May 2006 9:22] mike rahm

Description:
A problem with wildcards in show command:

mysql> show variables like "%\\\%";
Empty set (0.00 sec)

lists 0

a search with where works - this seems not to be clean ..
mysql> show variables where value like "%\\\%";
+---------------------------+-----------------------------------------------------+
| Variable_name             | Value                                               |
+---------------------------+-----------------------------------------------------+
| basedir                   | C:\Programme\MySQL\MySQL Server 5.0\                |
| character_sets_dir        | C:\Programme\MySQL\MySQL Server 5.0\share\charsets\ |
| datadir                   | C:\Programme\MySQL\MySQL Server 5.0\Data\           |
| innodb_log_group_home_dir | .\                                                  |
| language                  | C:\Programme\MySQL\MySQL Server 5.0\share\english\  |
| log_error                 | .\pco174.err                                        |
| pid_file                  | C:\Programme\MySQL\MySQL Server 5.0\Data\pco174.pid |
| slave_load_tmpdir         | C:\WINDOWS\TEMP\                                    |
+---------------------------+-----------------------------------------------------+

How to repeat:
show variables like "%\\\%";

show variables where value like "%\\\%";

Suggested fix:
like seems to work only on first collumn - should work for all collumns

[23 May 2006 11:10] mike rahm

sorry version is 5.0

[23 May 2006 11:53] Valeriy Kravchuk

Thank you for a problem report. Sorry, but it is not a bug. Please, read the manual (http://dev.mysql.com/doc/refman/5.0/en/show-variables.html):

"With a LIKE clause, the statement displays only those variables that match the pattern. To obtain a specific variable name, use a LIKE clause as shown:

SHOW VARIABLES LIKE 'max_join_size';
SHOW SESSION VARIABLES LIKE 'max_join_size';

To get a list of variables whose name match a pattern, use the ‘%’ wildcard character in a LIKE clause:

SHOW VARIABLES LIKE '%size%';
SHOW GLOBAL VARIABLES LIKE '%size%';"

So, LIKE is applied to varable names, not values.