I have recently spent a good deal of time attempting to navigate my way around sql command line code using ogr2ogr, within the current release of gdal. As per the title to this post I need to convert multipoint to point for a sqlite table using open source command line tools. So qgis or arcgis tools, etc are not possible solutions. I am not a programmer so I am looking for as direct a command line solution as possible, which can be scripted. I have explored saga gis command line options but the appropriate algorithm seems to not accept sqlite input? My best hope so far appears to be ogr2ogr in gdal. I have seen many examples of postgis code online (indeed, on stack exchange) which is supposed to facilitate this relatively simple operation, but I have been unable to rejig the code in sqlite to make it work for my input/desired output (again, sqlite), if indeed this is possible? My current command is:

ogr2ogr -gt 65536 -nlt POINT -f SQLite -spat -0.4 51.42 0.29 52.65 -dsco SPATIALITE=YES output.sqlite input.sqlite -nln outputname -dialect sqlite -sql "SELECT (ST_DumpPoints(geometry)) AS geometry from input"

I get a 'function does not exist' error.

Why do I get this?

1 Answer 1


I would start by reading the ogr2ogr manual http://www.gdal.org/ogr2ogr.html and then having a try with -explodecollections

-explodecollections: (starting with GDAL 1.8.0) produce one feature for each geometry in any kind of geometry collection in the source file

Basic command could be like

ogr2ogr -f SQLite -dsco spatialite=yes output.sqlite input.sqlite layer_name -explodecollections

If you can have other sort of geometries than points or multipoints in the input layer you may want to add some SQL for getting rid of polygons etc.

  • 1
    Thanks for this. I had perused the literature in some detail but missed '-explodecollections'. I often find gdal lit references to be rather oblique. Further, adding -unsetFid solved the subsequent 'unique constraint failed' error caused by output points using identifiers that were no longer so unique! Had I not used -unsetFid the operation would have either failed or I would have had to use -skipfailures, which would have removed the offending points from the output.
    – ctlgeowp
    Apr 6, 2017 at 18:11

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