def get_geom_placeholder(self, f, value, compiler):
        if value is None:
            return 'NULL'

        def transform_value(val, srid):
            return val.srid != srid

        if hasattr(value, 'as_sql'):
            if transform_value(value, f.srid):
                placeholder = '%s(%%s, %s)' % (self.transform, f.srid)
            else:
                placeholder = '%s'
            # No geometry value used for F expression, substitute in
            # the column name instead.
            sql, _ = compiler.compile(value)
            return placeholder % sql
        else:
            if transform_value(value, f.srid):
                return '%s(SDO_GEOMETRY(%%s, %s), %s)' % (self.transform, value.srid, f.srid)
            else:
                return 'SDO_GEOMETRY(%%s, %s)' % f.srid
Provides a proper substitution value for Geometries that are not in the
dataset/ETHPy150Open django/django/django/contrib/gis/db/backends/oracle/operations.py/OracleOperations.get_geom_placeholder