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Vector -> Data managment tools -> Join Attributes by Location . That's the tool i'm using.

When I use that tool, it merges the attributes from both polygon layers, but some of the attributes are incorrect. By incorrect, the attribute assumes a value of an adjacent polygon as opposed to the one it resides in.

When I use the tool Plugins -> mmqgis -> transfer -> merge layers. All of the attribute fields from Region B polygon are empty, yet Region A attribute is intact. The benefit of this is that all Region B polygon's inside the corresponding Region A polygon are correct. The previous example using Join Attributes by Location maintains the attribute data from both, but some of the attribute data is wrong.

How can I associate polygons from smaller regions inside a larger containing region while merging attribute data correctly?

Jamie none wrote:

Vector -> Data managment tools -> Join Attributes by Location . That's the tool i'm using.

When I use that tool, it merges the attributes from both polygon layers, but some of the attributes are incorrect. By incorrect, the attribute assumes a value of an adjacent polygon as opposed to the one it resides in.

you should share a sample of your data, pointing to an actual error in the result. Is this possible?

When I use the tool Plugins -> mmqgis -> transfer -> merge layers. All of the attribute fields from Region B polygon are empty, yet Region A attribute is intact. The benefit of this is that all Region B polygon's inside the corresponding Region A polygon are correct. The previous example using Join Attributes by Location maintains the attribute data from both, but some of the attribute data is wrong.

a Join and a merge are two different operations, so different result are expected anyway.

small districts inside large district files

I apologize for the confusion with multiple posts. The datasets are too large to upload, please see links below to obtain sample data.

http://www.cleanandgreenfuels.org/geotest/smalldist_insideLarge.zip <- small districts to be associated with larger districts.
http://www.cleanandgreenfuels.org/geotest/largedist.zip <- large districts to include smaller districts.
http://www.cleanandgreenfuels.org/geotest/Result.zip - output from combining the two files.

Jamie none wrote:

I apologize for the confusion with multiple posts. The datasets are too large to upload, please see links below to obtain sample data.

http://www.cleanandgreenfuels.org/geotest/smalldist_insideLarge.zip <- small districts to be associated with larger districts.
http://www.cleanandgreenfuels.org/geotest/largedist.zip <- large districts to include smaller districts.
http://www.cleanandgreenfuels.org/geotest/Result.zip - output from combining the two files.

hi,

the input layers (and the result too) have names that does not help understand what to do (using your desciption). Also the input layers do not have any attribute, so again it is not easy to understand what is wrong (if anything is wrong).

anyway it really seems that what you need is the "join by location tool", but without any attribute in the sample inputs it is hard to say if something is wrong.

sorry about the confusion. I wanted to merge the only attribute in the large region shapefile with the attributes contained in the small region shapefile. So the result showed the smaller regions belonging to the larger one.

The intersection tool worked for this. Initially i tried to Join Attributes by location, but this joined smaller regions into larger regions they were adjacent to as opposed to the ones they resided in.

mmqgis merge layers worked better, but it did not preserve the data from the smaller regions. it merely associated the larger regions with the smaller region, and nothing else. All other attributes were wiped out.

Closed for the lack of feedback