ST_OrderingEquals compares two geometries and returns 1 (TRUE) if the geometries are equal and the coordinates are in the same order; otherwise it returns 0 (FALSE).
Syntax
db2gse.ST_OrderingEquals(g1 db2gse.ST_Geometry, g2 db2gse.ST_Geometry)
Return type
Integer
Examples
The following CREATE TABLE statement creates the LINESTRING_TEST table, which has two linestring columns, L1 and L2.
CREATE TABLE LINESTRING_TEST (lid integer, l1 db2gse.ST_LineString, l2 db2gse.ST_LineString);
The following INSERT statement inserts two linestrings into L1 and L2 that are equal and have the same coordinate ordering.
INSERT INTO linestring_test VALUES (1,
db2gse.LineFromText('linestring (10.01 20.02, 21.50 12.10)', db2gse.coordref()..srid(0)),
db2gse.LineFromText('linestring (10.01 20.02, 21.50 12.10)',
db2gse.coordref()..srid(0)));
The following INSERT statement inserts two linestrings into L1 and L2 that are equal but do not have the same coordinate ordering.
INSERT INTO linestring_test VALUES (2,
db2gse.LineFromText('linestring (10.01 20.02, 21.50 12.10)', db2gse.coordref()..srid(0)),
db2gse.LineFromText('linestring (21.50 12.10,10.01 20.02)', db2gse.coordref()..srid(0)));
The following SELECT statement and corresponding result set shows how the ST_Equals function returns 1 (TRUE) regardless of the order of the coordinates. The ST_OrderingEquals function returns 0 (FALSE) if the geometries are not both equal and have the same coordinate ordering.
SELECT lid, db2gse.ST_Equals(l1,l2) equals, db2gse.ST_OrderingEquals(l1,l2) OrderingEquals FROM linestring_test lid equals OrderingEquals --- ------ ----------- 1 1 1 2 1 0