| Bug #43493 | union function returns polygon not multipolygon for non-intersecting polygons | ||
|---|---|---|---|
| Submitted: | 9 Mar 10:52 | Modified: | 7 May 14:01 |
| Reporter: | John Powell | ||
| Status: | Patch queued | ||
| Category: | Server: GIS | Severity: | S3 (Non-critical) |
| Version: | 5.1 WL#1326 | OS: | Linux |
| Assigned to: | Alexey Botchkov | Target Version: | |
| Tags: | gis, multipolygon, polygon, union function | ||
| Triage: | Triaged: D3 (Medium) | ||
[10 Mar 9:59]
Sveta Smirnova
Thank you for the report. Verified as described.
[7 May 14:01]
John Powell
Confirmed fixed. Thanks for the quick resolution.
Description: The union function performed on two non-intersection polygons returns a polygon and not a multipolygon. A polygon is defined as a single outer ring, with any number of inner rings. A multipolygon is defined as any number of non-intersecting polygons. How to repeat: create two non-intersection polygons mysql>set @geom=geomfromtext('POLYGON((0 0, 10 0, 0 10, 0 0))'); mysql>set @geom1=geomfromtext('POLYGON((100 100, 110 100, 100 110, 100 100))'); create new geometry, the union of these two: mysql>set @union=union(@geom, @geom1); select result mysql> select astext(@union); +----------------------------------------------------------------+ | astext(@union) | +----------------------------------------------------------------+ | POLYGON((0 0,0 10,10 0,0 0),(100 100,100 110,110 100,100 100)) | +----------------------------------------------------------------+ The result should be MULTIPOLYGON(((0 0,0 10,10 0,0 0)),((100 100,100 110,110 100,100 100)))