Retrieve the spatial reference id by which the geometry column is registered.

        This method is a veneer for an SQL query that calls the ``ST_SRID()`` function on the geometry column.

        Args:
            session (:mod:`sqlalchemy.orm.session.Session`): SQLAlchemy session object bound to PostGIS enabled database.

        Returns:
            str: PostGIS spatial reference ID.

def getSpatialReferenceId(self, session):
        """
        Retrieve the spatial reference id by which the geometry column is registered.

        This method is a veneer for an SQL query that calls the ``ST_SRID()`` function on the geometry column.

        Args:
            session (:mod:`sqlalchemy.orm.session.Session`): SQLAlchemy session object bound to PostGIS enabled database.

        Returns:
            str: PostGIS spatial reference ID.
        """
        statement = """
                    SELECT ST_SRID({0}) AS srid
                    FROM {1}
                    WHERE id={2};
                    """.format(self.geometryColumnName,
                               self.tableName,
                               self.id)

        result = session.execute(statement)

        for row in result:
            return row.srid