ST_Equalsrs checks to find if two spatial reference systems of two different feature classes are identical or not. If the spatial reference systems are identical, t (TRUE) is returned. If the spatial reference systems are not identical, ST_Equalsrs returns f (FALSE).
st_equalsrs (srid1 integer, srid2 integer)
In this example, the spatial reference IDs (SRID) of different feature classes are discovered, then ST_Equalsrs is used to see if the SRIDs represent the same spatial reference system or not.
SELECT srid, table_name
WHERE table_name = 'transmains' OR table_name = 'streets';
Now, use ST_Equalsrs to determine if the spatial reference systems identified by these two SRIDs are the same.
SELECT st_equalsrs(2,6) ;