Use ST_SrFromEsriWkt to convert Esri WKT to OGC WKT - PolarDB

Converts a spatial reference string from Esri well-known text (WKT) format to Open Geospatial Consortium (OGC) WKT format.

The key difference between the two formats is the DATUM name prefix: Esri WKT prefixes DATUM names with D_ (for example, D_China_2000), while OGC WKT omits that prefix (for example, China_2000).

Syntax

cstring ST_SrFromEsriWkt(cstring sr);

Parameters

Parameter	Description
`sr`	The spatial reference string in Esri WKT format.

Example

The following example converts a CGCS2000 (China Geodetic Coordinate System 2000) spatial reference string from Esri WKT to OGC WKT.

SELECT ST_srFromEsriWkt('GEOGCS["China Geodetic Coordinate System 2000",DATUM["D_China_2000",SPHEROID["CGCS2000",6378137,298.257222101]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]');

Output:

st_srfromesriwkt
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GEOGCS["China Geodetic Coordinate System 2000",DATUM["China_2000",SPHEROID["CGCS2000",6378137,298.257222101]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]

The D_ prefix in the DATUM name is removed: DATUM["D_China_2000",...] becomes DATUM["China_2000",...].

Usage notes

Use this function when your spatial reference string originates from an Esri tool such as ArcGIS or a Shapefile .prj file, and you need a standards-compliant OGC WKT string for subsequent spatial operations in PolarDB.

For a complete list of spatial reference functions, see the SpatialRef SQL reference.