Name
ST_SRID — Returns the spatial reference identifier for a geometry.
Synopsis
integer ST_SRID(geometry g1);
Description
Returns the spatial reference identifier for the ST_Geometry as defined in spatial_ref_sys table. Section 4.5, “Spatial Reference Systems”
![[Note]](../images/note.png)
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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. |
This method implements the OGC Simple Features
Implementation Specification for SQL 1.1.
s2.1.1.1
This method implements the SQL/MM specification.
SQL-MM 3: 5.1.5
This method supports Circular Strings and Curves.
Examples
SELECT ST_SRID(ST_GeomFromText('POINT(-71.1043 42.315)',4326));
--result
4326