[Qgis-user] relation_aggregate issue with virtual fields

[Neumann, Andreas]

Hi, 

I use a relation_aggregate expression with the following syntax: 

relation_aggregate( relation:='Erdwärmesonden',
aggregate:='sum',expression:="anzahl_sonden") 

In the output preview this works fine and I get an expected result,
however, if I use the same expression in a virtual field, I always get
NULL values. 

Any idea why this happens? 

Thanks, 

Andreas
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20170626/6b742617/attachment.html>