Bug #42203 cannot change the character_set_database value with ALTER DATABASE or db.opt

• Submitted: 19 Jan 2009 20:06
• Modified: 19 Jan 2009 21:16
• Reporter: Sheeri Cabral (Candidate Quality Contributor)
• Status: Can't repeat
• Category: MySQL Server: Charsets
• Severity: S2 (Serious)
• Version: 5.1.30-log Source distribution
• OS: Linux (CentOS 4.5, x86_64)
• CPU Architecture: Any
• Tags: alter database, BIG5, db.opt

[19 Jan 2009 20:06] Sheeri Cabral

Description:
I cannot change the value of the character_set_database with ALTER DATABASE nor with db.opt.

How to repeat:
mysql> create database test_charset default charset big5;
Query OK, 1 row affected %2

[19 Jan 2009 20:08] Sheeri Cabral

It helps when the web form actually accepts my content.  Take 2:

mysql> create database test_charset default charset big5;
Query OK, 1 row affected (0.07 sec)

mysql> \! more /dbs/mysql/test_charset/db.opt
default-character-set=big5
default-collation=big5_chinese_ci
mysql> use test_charset;
Database changed
mysql> show session variables like '%set_database%';
+------------------------+-------+
| Variable_name          | Value |
+------------------------+-------+
| character_set_database | big5  | 
+------------------------+-------+
1 row in set (0.00 sec)

#### OK so here we've established that the db was created and the db.opt file is correct, as is the character_set_database session variable.

#### now, let's changed the charset:
mysql> alter database test_charset default charset latin1;
Query OK, 1 row affected (0.00 sec)

mysql> show session variables like '%set_database%';
+------------------------+-------+
| Variable_name          | Value |
+------------------------+-------+
| character_set_database | big5  | 
+------------------------+-------+
1 row in set (0.00 sec)

mysql> \! more /dbs/mysql/test_charset/db.opt
default-character-set=big5
default-collation=big5_chinese_ci

### Hrm, let's try changing charset, not default charset?
mysql> \! more /dbs/mysql/test_charset/db.opt
default-character-set=big5
default-collation=big5_chinese_ci
mysql> alter database test_charset charset latin1;
Query OK, 1 row affected (0.00 sec)

mysql> \! more /dbs/mysql/test_charset/db.opt
default-character-set=big5
default-collation=big5_chinese_ci
mysql> show session variables like '%set_database%';
+------------------------+-------+
| Variable_name          | Value |
+------------------------+-------+
| character_set_database | big5  | 
+------------------------+-------+
1 row in set (0.00 sec)

#### nope, still doesn't work.  I'm pulling out the big guns, and modifying db.opt manually:

mysql> \! more /dbs/mysql/test_charset/db.opt
default-character-set=latin1
default-collation=latin1_swedish_ci

mysql> show session variables like '%set_database%';
+------------------------+-------+
| Variable_name          | Value |
+------------------------+-------+
| character_set_database | big5  | 
+------------------------+-------+
1 row in set (0.00 sec)

####odd!  Well, let's try flushing table to pick up the change?

mysql> flush tables;
Query OK, 0 rows affected (0.01 sec)

mysql> show session variables like '%set_database%';
+------------------------+-------+
| Variable_name          | Value |
+------------------------+-------+
| character_set_database | big5  | 
+------------------------+-------+
1 row in set (0.00 sec)

mysql> \! more /dbs/mysql/test_charset/db.opt
default-character-set=latin1
default-collation=latin1_swedish_ci

#### if I alter the database now, the db.opt file is written -- WITH THE WRONG INFORMATION!!

mysql> alter database test_charset charset latin1;
Query OK, 1 row affected (0.00 sec)

mysql> show session variables like '%set_database%';
+------------------------+-------+
| Variable_name          | Value |
+------------------------+-------+
| character_set_database | big5  | 
+------------------------+-------+
1 row in set (0.01 sec)

mysql> \! more /dbs/mysql/test_charset/db.opt
default-character-set=big5
default-collation=big5_chinese_ci

[19 Jan 2009 21:16] Mark Leith

Hi Sheeri, 

I can't repeat this:

Medusa:~/mysql mark$ mysql -u root -S mysql-5.1.30.sock 
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.1.30-log MySQL Community Server (GPL)

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> create database test_charset default charset big5;
Query OK, 1 row affected (0.00 sec)

mysql> use test_charset;
Database changed
mysql> show session variables like '%set_database%';
+------------------------+-------+
| Variable_name | Value |
+------------------------+-------+
| character_set_database | big5 | 
+------------------------+-------+
1 row in set (0.00 sec)

mysql> alter database test_charset default charset latin1;
Query OK, 1 row affected (0.01 sec)

mysql> show session variables like '%set_database%';
+------------------------+--------+
| Variable_name | Value |
+------------------------+--------+
| character_set_database | latin1 | 
+------------------------+--------+
1 row in set (0.00 sec)

Can you repeat this on a standard distribution by any chance? What modifications does your source distribution have?