I'm trying to define a GenericFunction that calls a PostGIS 3.0 function ( ST_AsGeoJson <https://postgis.net/docs/ST_AsGeoJSON.html>). The latest version can be called in two different ways:
SELECT ST_AsGeoJSON(t.geom) FROM foo as t WHERE t.id = 1; SELECT ST_AsGeoJSON(t.*) FROM foo as t WHERE t.id = 1; where the first example returns a GeoJSON Geometry, and the second returns a GeoJSON Feature. I'm only interested in making use of the second type / am happy to define the two variants separately. I should be able to subclass GenericFunction in order to do this, but I'm missing two details: 1. What should the return type of my subclass be? 2. How can I specify that I want to pass the record / row / all columns, as opposed to just the geom column to the underlying function? Ordinarily, attempting something like sess.query(func.MyGeojson(Foo)).all() Will give me an error: Object <class 'models.Foo'> is not legal as a SQL literal value -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sqlalchemy/f3718ff7-a252-41a9-8ac4-1ee2ee1e7f9f%40googlegroups.com.
