ST_SRID — Returns the spatial reference identifier for a geometry.


integer ST_SRID(geometry g1);


Returns the spatial reference identifier for the ST_Geometry as defined in spatial_ref_sys table. Section 4.5, “Spatial Reference Systems”


spatial_ref_sys table is a table that catalogs all spatial reference systems known to PostGIS and is used for transformations from one spatial reference system to another. So verifying you have the right spatial reference system identifier is important if you plan to ever transform your geometries.

Questo metodo implementa le OGC Simple Features Implementation Specification for SQL 1.1. s2.1.1.1

Questo metodo implementa la specifica SQL/MM. SQL-MM 3: 5.1.5

Questo metodo supporta le Curve e le Circular String.


SELECT ST_SRID(ST_GeomFromText('POINT(-71.1043 42.315)',4326));