MySQL db.opt File

When you create a database, you have to specify options such as the character set it will use:

 

mysql> create database andrew default charset utf8;

Query OK, 1 row affected (0.01 sec)

 

mysql>

 

These options are recorded in the db.opt file in the database directory:

 

UNIX > pwd

/usr/local/mysql/data/andrew

UNIX > cat db.opt

default-character-set=utf8

default-collation=utf8_general_ci

UNIX >

 

You can change them with the alter database command:

 

mysql> alter database andrew charset = dec8;

Query OK, 1 row affected (0.05 sec)

 

mysql>

 

... and the db.opt file will be updated:

 

UNIX > pwd

/usr/local/mysql/data/andrew

UNIX > cat db.opt

default-character-set=dec8

default-collation=dec8_swedish_ci

UNIX >

MySQL Character Set (part 2)

Go to part 1 

You can specify a database’s character set when you create it:

 

mysql> create database andrew

    -> default character set utf8;

Query OK, 1 row affected (0.00 sec)

 

mysql> show create database andrew;

+----------+-----------------------------------------------------------------+

| Database | Create Database                                                 |

+----------+-----------------------------------------------------------------+

| andrew   | CREATE DATABASE `andrew` /*!40100 DEFAULT CHARACTER SET utf8 */ |

+----------+-----------------------------------------------------------------+

1 row in set (0.00 sec)

 

mysql>

 

... and you can alter it subsequently as follows:

 

mysql> alter database andrew charset = latin1;

Query OK, 1 row affected (0.00 sec)

 

mysql> show create database andrew;

+----------+-------------------------------------------------------------------+

| Database | Create Database                                                   |

+----------+-------------------------------------------------------------------+

| andrew   | CREATE DATABASE `andrew` /*!40100 DEFAULT CHARACTER SET latin1 */ |

+----------+-------------------------------------------------------------------+

1 row in set (0.00 sec)

 

mysql>