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In QGIS I have a spatialite DB full of roads. I'd like to do a Difference operation (Vector > Geometry Tools > Difference) with another layer in order to keep roads only available in a given zone. The difference works fine but once I try to save that new layer to a Spatialite DB I get OGR error saying that it can't insert GEOMETRYCOLLECTION where a MULTILINESTRING is expected.

I don't know how to fix that and what to do.

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Following the @she_weeds' answer it was suggested to try saving that layer to another format and then to Spatialite. Saving it to GeoJSON worked, I could convert it to Spatialite after that and import it to my QGIS project (even if the auto-import didn't worked at first).

Even if everything works now using this workaround, I will update QGIS to latest version too.

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    Please show the dialog you used just before you get these errors. – bugmenot123 Nov 21 '18 at 10:53
  • @bugmenot123 hey thanks for your suggestion, I've edited the question and added two screenshots. I hope it helps. Thanks. – lvictorino Nov 21 '18 at 13:02
  • Does the layer TEST2 already exist in that spatialite file? – bugmenot123 Nov 21 '18 at 14:33
  • Nope. Should it? – lvictorino Nov 21 '18 at 14:37
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Try forcing the geometry by selecting Linestring as the geometry type and checking 'Force multi-type' in the dialog box you have shared.

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  • Thanks for your answer... Unfortunately it ends up with the same error: > Feature creation error (OGR error: Cannot insert feature with geometry of type GEOMETRYCOLLECTION in column GEOMETRY. Type MULTILINESTRING expected) – lvictorino Nov 21 '18 at 13:18
  • Bit of a long shot but I notice you're using QGIS 2.18, is it possible for you to try it with 3.x? I have done differences in virtual layers before that behaved as geometry collections in 2.x but would load as multipolygons in 3.x. – she_weeds Nov 21 '18 at 13:21
  • Also I take it you have retried the above after dropping the table and recreating it by saving the layer in QGIS (assuming this is a new table and that you are not appending data to an existing one) – she_weeds Nov 21 '18 at 13:23
  • Saving it in QGIS? how (sorry I'm new here). Is it with a "save as.." or a simple "save project" in qgis is enough? For now it's not saved, it's the result of the difference tool. So its layer source is defined as MultiLineString?uuid=73d12133-649c-4e9c-bc97-2ed45b044734&crs=EPSG:4326&field=.... What would you suggest to save it? (If it still fails after that I'll update my QGIS). Thanks for your time and help on this! – lvictorino Nov 21 '18 at 13:26
  • Just the "save as" - maybe save it as a completely different table (not overwriting or appending to TEST2) . I have tried recreating a similar scenario to yours with a multilinestring temp layer as the result of a difference from a polygon and line, layer source similar to yours, and saved it as a spatialite table in a new database using QGIS 2.18.15 without any errors (having forced the multilinestring geometry as I described)... – she_weeds Nov 21 '18 at 13:33

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