how to check user privileges in mysql code example

Example 1: mysql grant all privileges to a user

GRANT ALL PRIVILEGES ON database_name.* TO 'username'@'localhost';

Example 2: mysql check user privileges

SHOW GRANTS FOR 'root'@'localhost';

Example 3: mysql users and privileges list

SELECT * FROM information_schema.user_privileges;
SELECT CONCAT('SHOW GRANTS FOR ''',user,'''@''',host,''';') FROM mysql.user;
SHOW GRANTS FOR 'my_user'@'localhost';