code: public static function deleteWhere($condition = "", array $conditionParams = [])
  	{
  		$tableName = static::tableName();
  		
  		if (empty($condition))
  			return Db::query("delete from $tableName", [], static::getDbName(), false);
  		else
  			return Db::query("
  				delete from $tableName
  				where $condition
  			", $conditionParams, static::getDbName(), false);
  	}
docs: Delete all models that match condition
  
  @param string	$condition			delete condition
  @param array		$conditionParams	condition parameters
  
  @return bool|int number of rows deleted or false if fails