MySql character set and sorting rules: how to solve the problem of Chinese garbled characters

MySql is a very popular database management system, especially suitable for large-scale data storage and processing. However, when using MySql, we often encounter the problem of Chinese garbled characters. This is because the character set and collation of MySql are not set correctly. The following will introduce how to solve the problem of Chinese garbled characters.

1. MySql’s character set and collation rules

MySql supports multiple character sets and collation rules. The character set determines which characters can be stored in the database, and the collation determines how these characters are sorted and compared. Common character sets include UTF-8, GB2312, GBK, etc., while sorting rules include utf8_general_ci, gbk_chinese_ci, etc.

2. The cause of the Chinese garbled code problem

The root cause of the Chinese garbled code problem is that the character set and sorting rules do not match. For example, if the database uses the GBK character set and the application uses the UTF-8 character set, garbled characters will appear during character conversion. In addition, the MySql Chinese garbled problem may also be caused by incorrect client or server character set settings, character type mismatch, or insufficient character length.

3. Methods to solve the problem of Chinese garbled characters

1. Set MySql default character set and collation rules

When creating a database, you should specify the character set and collation rules. For example:

CREATE DATABASE mydb DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;

This will create a database named "mydb" and set its character set to UTF-8 and collation settings is utf8_general_ci.

2. Modify the character set and collation of the table

If the database has been created but the character set and collation are incorrect, you can modify the character set and collation of the table through the following command:

ALTER TABLE tablename CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;

Among them, tablename is the name of the table to be modified.

3. Set the client character set

When using the mysql client to connect to MySql, you can set the client character set through the following command:

mysql --default-character -set=utf8 -u username -p password

Among them, utf8 is the character set to be set.

4. Set the application character set

When developing an application, you should set the application's character set and collation to match the database's character set and collation. For example, in PHP, you can set the character set through the following code:

mysqli_set_charset($conn, "utf8");

where $conn is the database connection object and utf8 is the character to be set set.

5. Use the correct character type and length

When creating a table, you should choose the correct character type and length. For example, when storing Chinese, you should use VARCHAR or TEXT type and set a sufficient length. If the length is insufficient, problems with Chinese truncation may occur.

6. Conclusion

MySql’s character set and sorting rules are the key to solving the problem of Chinese garbled characters. Only by correctly setting the character set and sorting rules can we ensure that the data will not be garbled during storage and processing. Therefore, it is recommended that when using MySql, you must carefully select the character set and collation, and ensure that the application's character set and collation match the database.

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