MySQL CREATE USER ze zmienną?

Możesz użyć dynamic SQL jako:

SET @query1 = CONCAT('
        CREATE USER "',@username,'"@"localhost" IDENTIFIED BY "',@password,'" '
        );
PREPARE stmt FROM @query1; EXECUTE stmt; DEALLOCATE PREPARE stmt;

SET @query1 = CONCAT('
    GRANT USAGE ON *.* TO "',@username,'"@"localhost" IDENTIFIED BY "',@password,'" WITH
          MAX_QUERIES_PER_HOUR 120 MAX_CONNECTIONS_PER_HOUR 60 MAX_UPDATES_PER_HOUR 60 
          MAX_USER_CONNECTIONS 2'
        );
PREPARE stmt FROM @query1; EXECUTE stmt; DEALLOCATE PREPARE stmt;