ST_CompareWKT(LONG VARCHAR, LONG VARCHAR) method

Syntax

ST_SpatialRefSys::ST_CompareWKT(LONG VARCHAR transform_definition_1, LONG VARCHAR transform_definition_2)

Parameters

• transform_definition_1 – The first spatial reference system definition text
• transform_definition_2 – The second spatial reference system definition text

Returns

BIT Returns 1 if the two spatial reference systems are logically equivalent, otherwise 0.

Examples

• Example 1 – The following example shows that two spatial reference systems are considered equal even though they have different names:

  SELECT  ST_SpatialRefSys::ST_CompareWKT(
  'GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]]'
  ,   'GEOGCS["WGS 84 alternate name",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]]'
  ) Considered_Equal

  The following example shows two spatial reference systems that are considered non-equal because they are defined by different authorities:

  SELECT  ST_SpatialRefSys::ST_CompareWKT(
  'GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]]'
  ,   'GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["AnotherAuthority","4326"]]'
  ) Considered_NotEqual

Standards

SQL/MM (ISO/IEC 13249-3: 2006) Vendor extension