Add feature to postgis layer with sequenced id using pyqgis

Question

Using python, I want to add a feature into a postgis layer that has a PK generated by a sequence.

layer (id [PK], field1, field2)

with edit(layer):
            fields = layer.pendingFields()
            new_feat = QgsFeature(fields)
            new_feat[1] = 'text1'
            new_feat[2] = 'text2'

            layer.addFeatures([new_feat])

But I get an error saying the value is too long for the type of the id attribute

Question: How can I assign the next value of the postgis sequence to the id?

score 0 · Answer 1 · answered Mar 02 '18 at 14:30

0

try the following:

with edit(layer):
    fields = layer.pendingFields()
    new_feat = QgsFeature(fields)
    newFeat.setAttributes([NULL, 'text 1', 'text 2'])

    layer.addFeatures([new_feat])

answered Mar 02 '18 at 14:30

firefly-orange

2,521
6
23

I tried already but it doesn't work. I get the same error – var29 Mar 02 '18 at 14:35
It's strange that an explicit NULL is returning a "too long" message. What specific constraints do you have on the PK and can you create a feature on the layer without using PyQGIS? – firefly-orange Mar 02 '18 at 14:51
Indeed! Yes I can add a feature in QGIS, or with PyQGIS if I give the value of the next val manually. I have a sequence generated by a function. – var29 Mar 02 '18 at 14:59
Have you tried replacing with edit(layer): with layer.startEditing() – firefly-orange Mar 02 '18 at 15:48
Yes that is what I had before, but it didn't work neither. – var29 Mar 05 '18 at 07:08

score 0 · Answer 2 · answered Mar 05 '18 at 10:31

0

This post gives the solution: How to create a QgsFeature with default attributes?

Can anyone mark this question has a duplicate?

answered Mar 05 '18 at 10:31

var29

51
6

Add feature to postgis layer with sequenced id using pyqgis

2 Answers2