anchor.diff:          type = types.package;
           example = literalExample "pkgs.mysql";
           description = "
  -          Which MySQL derivation to use.
  +          Which MySQL derivation to use. MariaDB packages are supported too.
           ";
         };
   
  
positive.code:   cfg = config.services.mysql;
  
    mysql = cfg.package;
  
    atLeast55 = versionAtLeast mysql.mysqlVersion "5.5";
  
  
negative.code: 
              ${concatMapStrings (user:
                ''
                  ( echo "CREATE USER IF NOT EXISTS '${user.name}'@'localhost' IDENTIFIED WITH ${if isMariaDB then "unix_socket" else "auth_socket"};"
                    ${concatStringsSep "\n" (mapAttrsToList (database: permission: ''
                    echo "GRANT ${permission} ON ${database} TO '${user.name}'@'localhost';"
                    '') user.ensurePermissions)}
  