In QGIS 3.16. I have a layer of 1000+ polygons, many of which are adjacent (touching, overlapping, or one completely inside another). If all of the adjacent polygons are merged, I will end up with between 100 and 200 (larger) polygons.
I would like to accomplish this in a way that preserves all of the attributes for all polygons, for example:
For polygons being merged: values for attribute X are concatenated for the resulting polygon. (Example: For attribute 'status', Polygon A has value "IC" and Polygon B has value "NC". If these two polygons merge into Polygon AB, I would like the corresponding value of attribute 'status' to be "IC, NC".)
For polygons not being merged (i.e. isolated ones without an adjacent neighbor) there is no change to their attributes.
This seems like a fairly common task that it should be possible to accomplish, but my searches have been fruitless thus far.
I'd like to stay within QGIS if possible (I have never used PostGIS before). If your answer involves SQL or Python, please consider that I am learning these now but an absolute beginner, so I will not understand code without context.