lookups.py 文件源码

def process_rhs(self, compiler, connection):
        rhs, rhs_params = super(GISLookup, self).process_rhs(compiler, connection)
        if hasattr(self.rhs, '_as_sql'):
            # If rhs is some QuerySet, don't touch it
            return rhs, rhs_params

        geom = self.rhs
        if isinstance(self.rhs, Col):
            # Make sure the F Expression destination field exists, and
            # set an `srid` attribute with the same as that of the
            # destination.
            geo_fld = self.rhs.output_field
            if not hasattr(geo_fld, 'srid'):
                raise ValueError('No geographic field found in expression.')
            self.rhs.srid = geo_fld.srid
        elif isinstance(self.rhs, Expression):
            raise ValueError('Complex expressions not supported for GeometryField')
        elif isinstance(self.rhs, (list, tuple)):
            geom = self.rhs[0]
        rhs = connection.ops.get_geom_placeholder(self.lhs.output_field, geom, compiler)
        return rhs, rhs_params