How Do I Change Database, Table, and Column Collation Using SQL?

Altering Collation for Database, Table, and Column

To alter the collation for a database, table, or column, there are specific SQL commands that can be executed. Setting changes through PhpMyAdmin may not be an option for bulk modifications.

Changing Database Collation

ALTER DATABASE <database_name> CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

This command sets the new default collation for the database. However, it will not modify existing tables.

Changing Table Collation

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

This command converts the entire table to the specified collation, including its columns.

Changing Column Collation

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

This command modifies the collation for a specific column within a table. It can be used to alter the collation of individual columns without affecting the table's overall collation.

Note: It is generally recommended to change the collation at the table level as it automatically updates the columns as well. Changing the collation for specific columns is typically only necessary in exceptional circumstances.

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