How can I add another WHERE filter to a PostGIS query?

Question

I have this query, which works well, for an OSM database:

SELECT row_to_json(fc)
FROM (
  SELECT ST_AsGeoJSON(ST_Transform(ST_Intersection(lg.geometry, bbox.geom), 4326))::json As geometry,
  (
    SELECT row_to_json(t)
    FROM (
      SELECT name, type, admin_level
    ) t
  )
As properties
FROM
  osm_admin As lg,
  (SELECT ST_Transform(ST_MakeEnvelope(10.735445022583008, 59.913428634991995,
      10.776472091674805, 59.933989460416115, 4326),3857) as geom) as bbox
    WHERE ST_Intersects(lg.geometry, bbox.geom)
  ) fc;

I'd like to filter this generic query a bit, depending on the zoom level. E.g. I'd like to add filter for zoom level WHERE admin_level < 4. I also need to add other filters for other queries, based on this template (where admin_level is a property of the osm_admin table).

Where can I insert such a WHERE clause?

Answer 1

Please add WHERE ST_Intersects(lg.geometry, bbox.geom) AND admin_level < 4. This will give you the result for those features which intersect with the given geometry AND whose admin_level is less than 4.

Answer 2

Just use AND in your WHERE clause...