In QGIS 2.6, creating a virtual field for a layer and adding up 2 integer fields work fine. I get the correct results and I can use that field for styling.
However, when doing a Joins with 2 layers and using a virtual field to add up an integer column from each layer, the results displayed are correct. But QGIS does not recognise the values when styling.
When I try to classify this in the Categorized styling option, no data values are recognised.
The virtual field tooltip describes:
"A virtual field will be recalculated every time it is used. Its definition will be saved in the project file. It will not be saved in the dataprovider and therefore its values not be available in other software."
As it won't be saved in the dataprovider, does that mean QGIS is not even able to read the data? Strangely, I am able to export the layer, including the virtual field, as a .csv which outputs all the correct results for the virtual field.
Is this a possible bug?
The bug report for this problem has been Closed, although I will wait until the next major version of QGIS to test this.
If anyone can confirm this (with screenshots preferably) then I will happily accept your answer.