I want to merge two shape files in which one is of point geometry type and other is polygon type in order to get a single layer containing both points and polygon in a single map.
[GIS] Merging shapefiles with different geometries (point and polygon) to get single layer with multiple geometries
file formatsgeojsonqgisshapefile
Related Solutions
Use the Merge (Data Management) geoprocessing tool.
It should give you a merged polygon with all the attributes intact.
I would suggest to create that unique "id". The following workflow can be applied.
Let's assume there there area two polygon layers 'dresden_buildings_test' and 'dresden_buildings_test2' with features that possess equal geometries but have different attributes (data was taken from https://www.geofabrik.de/de/data/shapefiles.html), see image below.
Step 1. Create a unique "id" in one layer, using for instance $id+ 1 or @row_number.
Step 2. Get that unique "id" by comparing geometries using the overlay_equals() function in the Field Calculator.
I used this expression:
overlay_equals('dresden_buildings_test', "id")[0]
and got this output:
Hereafter I check if they are the same
Alternative to approch in the Step 2. try the "Join attributes by location" with equals as 'Geometric predicate'.
As @Erik wrote about "centroid" and you said "comparing polygon centroids", however I will probably use the "Point on surface", because building can have holes and strange shapes.
Best Answer
Shapefile format doesn't allow multiple geometry types, so you should use another format, like GeoJSON. See also OGR merge shapefiles of different geom type into a single GeoJSON feature collection, How to Merge/Join GeoJSON and JSON? and https://gist.github.com/migurski/3759608