public function setIndices( $indices )
	{
		foreach( $indices as $index )
		{
			if( !in_array( $index, $this->columns ) )
				throw new \InvalidArgumentException( 'Column "'.$index.'" is not existing in table "'.$this->tableName.'" and cannot be an index' );
			if( $index === $this->primaryKey )
				throw new \InvalidArgumentException( 'Column "'.$index.'" is already primary key and cannot be an index' );
		}
		$this->indices	= $indices;
		array_unique( $this->indices );
	}