	public function addTable( $table, $alias ) {
		if ( empty( $table ) ) {
			throw new \MWException( __METHOD__ . ': An empty table name was passed.' );
		}
		if ( empty( $alias ) || is_numeric( $alias ) ) {
			throw new \MWException( __METHOD__ . ': An empty or numeric table alias was passed.' );
		}
		if ( !isset( $this->tables[$alias] ) ) {
			$this->tables[$alias] = $this->DB->tableName( $table );
			return true;
		} else {
			return false;
		}
	}