I'm working with these data: click here. The task is actually pretty simple but somehow it won't work properly.
I have a point and a polygon layer. In most polygons there are a couple of points. The point layer has an attribute called EWZ. I just want to add EWZ to each polygon and it shall be the sum of EWZ of all points which lie within the polygon.
I used the point to polygone function where I chose under statistical methods or aggregation method (not sure how it is called in the english version) sum.
But if I generate the now layer, the values are not correctly aggregated. I also tried max and standard deviation. However, in the new field EWZ_Sum always appears just the value of one of the previous points and not the aggregated value.
Is this a bug or am I missing something? I'm using QGIS 2.12.1.