[Qgis-developer] Using aggregates functions to count intersected features from another layer

DelazJ delazj at gmail.com
Wed Oct 19 03:37:07 PDT 2016


Hi,

I have a polygon layer and a point one.
I'd like to calculate for each polygon feature, the number of points that
it covers. I thought the aggregates functions could help me find an easier
and straight expression to perform this (without creating intermediate
layers) but I fail to find any correct syntax.

I tried aggregate ('mypoint', 'count', "id", intersects ($geometry,
geometry($currentfeature)))

 And many variants of the fourth option but It always return the total of
points or an error. Actually this option is a filter and I wonder if i'm
not missing a "group by" option in the aggregate function (which seems to
be the appropriate one in my case). Is it possible?

The work around I found is to populate an ad'hoc field in the point layer
with overlapping polygon id, thanks to the SpatialJoin plugin, then I
create a one-to-many relation in the project between the two layers in
other to use relation_aggregate function.
But I expected something more direct.

Any hint, please?

Thanks,
Harrissou
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