code: public function checkDbExists($name)
      {
          $data = $this->query("SELECT COUNT(*) AS total FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = '".$this->escape($name)."'", true);
          if( isset($data['0']['total']) && $data['0']['total'] == '1' )
          {
              return true;    
          }
          
          return false;
      }
docs: Determines whether a given database exists
  @param string $name
  @return boolean