I am trying to get dissolve functionality using ST_Union using this query : SELECT c.fid, ST_Union(c.boundaryshape) FROM c GROUP BY c.fid; Than I found instead of using ST_Union I should use ...
I am trying to achieve an equivalent to the Dissolve tool from ArcGIS for Desktop using ST_Union from PostGIS but it seems I am not getting expected result. I have one table which has certain ...
I've been reading a number of related threads about ST_Union, ST_SnapToGrid and ST_Dump but I haven't been able to solve my problem. The problem is I am trying to merge Tiger/line census tracts that ...
I have approximately 1 million polygons that have been split by lines. However, this has caused one half of a polygon to be separated by approximately 50cm from its other half. After doing a lot of ...
In PostGIS, how do I merge a multilinestring into a single linestring, keeping the pieces in proper order?
I have a multilinestring made up of several pieces, some of which are facing the wrong direction. (Accessible here: http://pastebin.com/89Zcixv5 ) I think what I'm looking for is some utilization of ...
PostGIS - Why are my ST_Union results (stored in a new table) outputting as points and not polygons?
I've decided to move to PostGIS to merge polygons rather than spend hours doing in in QGIS. However, I'm hitting an issue where the results of an ST_Union query are being stored, or at least outputted ...
I have the following layer using SRID 27700 in postgis: It's every administrative region in the UK, and (as you can see from the colour grouping) each of them has a text field specifying the county ...
I have a table in PostGIS with a quite fine partition of a region, which I'd like to dissolve at two higher levels by means of two foreign keys (e.g. municipality and state). The partition is a real ...
I'm looking for a function to dissolve shared boundaries between polygon features in a table. ST_UNION() almost does what I'm looking for, but it creates a multipolygon from all polygons in the layer ...