[MDEV-6996] SET STATEMENT default_week_format = .. has no effect Created: 2014-11-01  Updated: 2015-02-02  Resolved: 2014-12-02

Status: Closed
Project: MariaDB Server
Component/s: Admin statements
Affects Version/s: N/A
Fix Version/s: 10.1.2

Type: Bug Priority: Major
Reporter: Elena Stepanova Assignee: Oleksandr Byelkin
Resolution: Fixed Votes: 0
Labels: None

Issue Links:
Relates
relates to MDEV-5231 Per query variables from Percona Serv... Closed
relates to MDEV-6923 Testing for SET STATEMENT .. FOR (MDE... Closed

 Description    

MariaDB [test]> SELECT @@default_week_format;
 
+-----------------------+
 
| @@default_week_format |
 
+-----------------------+
 
|                     0 |
 
+-----------------------+
 
1 row in set (0.00 sec)
 
 
 
MariaDB [test]> SELECT WEEK('2000-01-01');
 
+--------------------+
 
| WEEK('2000-01-01') |
 
+--------------------+
 
|                  0 |
 
+--------------------+
 
1 row in set (0.00 sec)
 
 
 
MariaDB [test]> SELECT WEEK('2000-01-01',2);
 
+----------------------+
 
| WEEK('2000-01-01',2) |
 
+----------------------+
 
|                   52 |
 
+----------------------+
 
1 row in set (0.00 sec)
 

MariaDB [test]> SET STATEMENT default_week_format = 2 FOR SELECT WEEK('2000-01-01');
 
+--------------------+
 
| WEEK('2000-01-01') |
 
+--------------------+
 
|                  0 |
 
+--------------------+
 
1 row in set (0.01 sec)
 
 
 
MariaDB [test]> SET default_week_format = 2;
 
Query OK, 0 rows affected (0.00 sec)
 
 
 
MariaDB [test]> SELECT WEEK('2000-01-01');
 
+--------------------+
 
| WEEK('2000-01-01') |
 
+--------------------+
 
|                 52 |
 
+--------------------+
 
1 row in set (0.00 sec)

All the same in Percona server.



 Comments   
Comment by Oleksandr Byelkin [ 2014-11-05 ]

The problem is that week format put as an constant argument during parsing:

            Item *i1= new (thd->mem_root) Item_int((char*) "0",
 
                                           thd->variables.default_week_format,
 
                                                   1);
 
            if (i1 == NULL)
 
              MYSQL_YYABORT;
 
            $$= new (thd->mem_root) Item_func_week($3, i1);
 
            if ($$ == NULL)
 
              MYSQL_YYABORT;

Comment by Oleksandr Byelkin [ 2014-11-05 ]

The variable prohibited as a workaround.

Comment by Oleksandr Byelkin [ 2014-11-11 ]

Parameters set during parsing so changing variables has no effect.

Comment by Sergei Golubchik [ 2014-11-29 ]

This is a bug, a variable should not be set during parsing.
So, keep it enabled and fix the following bug instead:

create table t1 (a date);
 
insert t1 values ('2001-01-01');
 
prepare x from "select week(a) from t1";
 
execute x;
 
set default_week_format = 2;
 
execute x;
 
alter table t1 engine=myisam;
 
execute x;

Comment by Sergei Golubchik [ 2014-11-29 ]

An easy fix would be to generate Item_func_get_system_var for a second argument.

Comment by Oleksandr Byelkin [ 2014-12-01 ]

I did a bit different but fix is:
[Commits] b14de6a: MDEV-6996: SET STATEMENT default_week_format = .. has no effect
20.11.14 11:32

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