I am using QGIS 3.6.4 and working with GeoJSON files. I have come across a very annoying problem. Whenever I try to add an attribute and assign values to it using the field calculator, the values will appear to update and the field looks correctly populated. However as soon as I exit out of the attribute table (while saving changes) and reopen it the entire column is converted to NULL.
I have tried playing around with the precision and width of the output field to no avail. I don't think this is related to coordinate system units since this is not a geometric operation of type
$length. It is more like Acol1+Bcol2.
Has anyone had such an issue before? Please help... I would have thought basic functionality like this is already well tested and bug free in QGIS....
Other symptoms include:
- new field disappears if I remove the layer and add it again from file location, despite having saved layer changes....
- a separate geojson file called result.geojson.tmp is created and contains the modified attribute table. However my result.geojson is unchanged. Adding an attribute field and populating it should not create a new file but modify the current one in place... why does this happen?
- I have also attempted this with QGIS 3.6.1 - Same problem.
The problem appears to be under discussion in the QGIS issue tracker