How to create a valid QgsVectorLayer from a PostgreSQL view?

Question

I am attempting to create a QgsVectorLayer with the same code as I am using for a PostgreSQL table, which works correctly and the isValid() method on the layer returns true.

uri=QgsDataSourceUri()
uri.setConnection("localhost","5433","xxx","postgres","xxx",QgsDataSourceUri.SslDisable)
uri.setDataSource("xxx","sv_demog","geom","id")
uri.setSrid("4269")
vlayer=QgsVectorLayer(uri.uri(),"xxxx","postgres")
print('sv_demog layer is valid: %s' % (vlayer.isValid()))

The view selects from table where id is the primary key, and has a geometry column.

How do I make this work for a view?

I am using a PostgreSQL 10 database, and QGIS 3 (Update: Same behavior in 2.18).

Ref: Loading Layers

Answer 1

Jay, I had the same problem. You have to specify the view's primary key. For example, uri.setDataSource('my schema', 'my_view', 'geom', '', 'id')

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