ST_IsGeographicCRS

Signature

BOOLEAN ST_IsGeographicCRS(GEOMETRY geom);

Description

Takes a geometry (geom) and return TRUE is the coordinate system is geographic.

This function will return FALSE if:

the coordinate system is geometric,
the geometry is null,
the geometry’s SRID is equal to 0.

Tip

Find the SRID you’re looking for

All available CRS SRIDs may be found by executing the query SELECT * FROM SPATIAL_REF_SYS;. Most SRIDs are EPSG, but the SPATIAL_REF_SYS table may be enriched by other CRSes.

Examples

Case with no SRID

Here we have a POINT whose coordinates are exprimed in WGS84 - EPSG:4326, but no SRID is applied

SELECT ST_IsGeographicCRS('POINT(-1.53391 47.20259)');

-- Answer: FALSE

Case with a SRID

With the same POINT seen before, we force the SRID to be in WGS84 - EPSG:4326

SELECT ST_IsGeographicCRS(ST_SetSRID('POINT(-1.53391 47.20259)', 4326));

-- Answer: TRUE

Same POINT, but exprimed and forced in Lambert 93 (legal system in France - EPSG:2154), which is not a geographic system

SELECT ST_IsGeographicCRS(ST_SetSRID('POINT(356964.672 6687884.168)', 2154));

-- Answer: FALSE