mysql set character set

2. Set the character set of the database

When we create a new MySQL database, we can set the default character set of the database, so that the character set of all tables in the database will be used the character set. The specific steps are as follows:

2.1 First check the character sets supported by MySQL

mysql> SHOW CHARACTER SET;

2.2 When creating a new database, add a character set setting Define

CREATE DATABASE new_db CHARACTER SET utf8;

or

CREATE DATABASE new_db DEFAULT CHARACTER SET utf8;

where utf8 is one of the commonly used character sets.

3. Set the character set of the MySQL table

In order for the fields of the table to store and display data correctly, we need to set the character set for the table. In MySQL, the character set of a table can be set when creating the table. If the table has been created, you can also modify the table through the Alter command.

3.1 Set the character set when creating the table

CREATE TABLE new_table (
id INT(11) NOT NULL AUTO_INCREMENT,
name VARCHAR(50) NOT NULL DEFAULT '',
PRIMARY KEY (id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

Among them, ENGINE=InnoDB is used to set the storage engine of the table, and CHARSET=utf8 is used to set the default character set of the table. .

3.2 Modify the character set of the table

ALTER TABLE old_table CONVERT TO CHARACTER SET utf8;

or

ALTER TABLE old_table MODIFY COLUMN name VARCHAR(50) CHARACTER SET utf8;

Among them, the CONVERT TO command is used to modify the default character set of the table, and the MODIFY COLUMN command is used to modify the character set of a column in the table.

4. Set the character set for MySQL connection

When connecting to the MySQL server, you can also set the character set for the operation. This character set setting is often called the "client character set" and refers to the character set of data transmitted in the client.

4.1 View the character set of the current connection

mysql> SELECT @@character_set_connection;

4.2 Modify the character set of the connection

SET character_set_connection = utf8;

or

mysql --default-character-set=utf8 -u root -p

Among them, the SET command can modify the default character set of the connection, --default-character The -set command can specify the client character set.

5. Other character set settings

In some cases, you may need to open other character set settings of MySQL to handle some rare data storage and conversion Scenes. At this time, you may need to modify the MySQL configuration file - my.cnf file. Modifying this file may require administrator rights. The modification method is as follows:

5.1 Find the my.cnf file

In Linux, the my.cnf file is usually stored in the /etc/my.cnf or /etc/mysql/my.cnf directory .

In Windows, the my.cnf file is usually stored in the installation directory of the MySQL database.

5.2 Modify the my.cnf file

Add the following statement in the my.cnf file:

[mysqld]
character_set_server=utf8
init_connect='SET NAMES utf8'

Among them, the character_set_server command is used to set the listed character set, and the init_connect command is used to automatically set the character set when creating a connection.

6. Summary

MySQL is a very popular open source database, and its character set setting plays a very important role. Correctly setting the character set of MySQL ensures normal reading, writing and storage of data. In this article, we introduce the basic concepts of MySQL character sets, how to set character sets when creating databases, tables, and connections, and how to modify the my.cnf file to enable more character set settings. This knowledge can help developers better use MySQL.