Converting Database Charset and Collation for WordPress

Warning: Before beginning any conversion, please back up your database.

To see the default charset and collation for all the databases you have on the server, you can use the statement below:

SELECT SCHEMA_NAME 'database', DEFAULT_CHARACTER_SET_NAME 'charset', DEFAULT_COLLATION_NAME 'collation' FROM INFORMATION_SCHEMA.SCHEMATA;

To see the default character set and collation for a given database, use this statement:

SELECT SCHEMA_NAME 'database', DEFAULT_CHARACTER_SET_NAME 'charset', DEFAULT_COLLATION_NAME 'collation'
FROM INFORMATION_SCHEMA.SCHEMATA
WHERE SCHEMA_NAME = 'databasename';

Converting Database Charset and Collation

For WordPress sites, the recommended character set is utf8mb4 and the recommended collation is utf8mb4_unicode_ci. You can use these statements to change the default charset and collation for a database, or to convert the charset and collation for a table.

-- Change the default charset & collation for a database
ALTER DATABASE databasename CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

-- Convert for a table
ALTER TABLE tablename CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;