code: public void setCatalog(String catalog) throws QueryException
      {
          if (getDatabaseType() == SupportedDatabases.MYSQL)
          {
              executeQuery(new DrizzleQuery("USE `" + catalog + "`"));
              this.database = catalog;
          }
          // else (Drizzle protocol): silently ignored since drizzle does not
          // support catalogs
      }
docs: Catalogs are not supported in drizzle so this is a no-op with a Drizzle
  connection<br>
  MySQL treats catalogs as databases. The only difference with
  {@link MySQLProtocol#selectDB(String)} is that the catalog is switched
  inside the connection using SQL 'USE' command