How to Change Collations in MySQL Databases, Tables, and Columns?

Altering Collation in Databases, Tables, and Columns: A Comprehensive Guide

MySQL collations determine the rules for comparing, sorting, and storing data. Changing collations can become necessary to enhance data handling and character set compatibility.

Changing Database Collation

To alter the collation of an entire database, execute the following query:

ALTER DATABASE <database_name> CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

Note that this will only set a new default for newly created tables, without modifying existing ones.

Changing Table Collation

To convert the collation of a specific table, use the following query:

ALTER TABLE <table_name> CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

This approach is recommended as it also modifies the collation of all columns.

Changing Column Collation

For specific scenarios, you may need to alter the collation of an individual column:

ALTER TABLE <table_name> MODIFY <column_name> VARCHAR(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

Choosing the Right Collation

The "utf8mb4_unicode_ci" collation is recommended for most purposes as it supports a wide range of characters and provides Unicode-compliant sorting. However, your specific requirements and application context may dictate the appropriate choice of collation.

The above is the detailed content of How to Change Collations in MySQL Databases, Tables, and Columns?. For more information, please follow other related articles on the PHP Chinese website!