ST_SRID-ApsaraDB RDS(RDS)-阿里云帮助中心

Returns the spatial reference identifier (SRID) of a trajectory. ApsaraDB RDS uses the SRID to look up the corresponding spatial reference system in spatial_ref_sys, which ensures that spatial calculations are performed correctly.

Syntax

int ST_SRID(trajectory traj);

Parameters

Parameter	Description
`traj`	The trajectory whose SRID to return.

Usage notes

Each SRID maps to a row in the spatial_ref_sys system table, which stores the geographic coordinate system and projection information for that spatial reference system.
The default SRID is 0.

Example

SELECT ST_SRID('{"trajectory":{"version":1,"type":"STPOINT","leafcount":2,"start_time":"2007-05-27 00:00:00","end_time":"2007-05-28 08:36:47.846","spatial":"LINESTRING(13.43593 52.41721,13.43593 52.41721)","timeline":["2007-05-27 00:00:00","2007-05-28 08:36:47.846"]}}'::trajectory);
 st_srid
---------
       0
(1 row)