ST_SRID — Returns the spatial reference identifier for a topogeometry.
integer ST_SRID(topogeometry tg);
Returns the spatial reference identifier of the topology containing the TopoGeometry.
The identifier is recorded for the topology when it is created and refers to an entry in Section 4.5, “Spatial Reference Systems”.
Availability: 3.2.0
Return the SRID of a TopoGeometry stored in the ri_topo topology.
SELECT topology.ST_SRID(topo) AS srid FROM ri.roads WHERE road_name = 'Unknown';
srid ------ 3438