1 of 1

ST_SYMDIFFERENCE

Returns a geometry representing the point set symmetric difference of two geometries. It outputs the spatial area present in either geometry but not in both.

Syntax

ST_SYMDIFFERENCE(g1,g2)

Description

Returns a geometry that represents the portions of geometry g1 and geometry g2 that don't intersect.

Examples

_{This page is licensed: CC BY-SA / Gnu FDL}

SET @g1 = ST_GEOMFROMTEXT('LINESTRING(10 20, 10 40)');

SET @g2 = ST_GEOMFROMTEXT('LINESTRING(10 15, 10 25)');

SELECT ASTEXT(ST_SYMDIFFERENCE(@g1,@g2));
+----------------------------------------------+
| ASTEXT(ST_SYMDIFFERENCE(@g1,@g2))            |
+----------------------------------------------+
| MULTILINESTRING((10 15,10 20),(10 25,10 40)) |
+----------------------------------------------+

SET @g2 = ST_GeomFromText('LINESTRING(10 20, 10 41)');

SELECT ASTEXT(ST_SYMDIFFERENCE(@g1,@g2));
+-----------------------------------+
| ASTEXT(ST_SYMDIFFERENCE(@g1,@g2)) |
+-----------------------------------+
| LINESTRING(10 40,10 41)           |
+-----------------------------------+