Getting active PostgreSQL connection username when stored through authentication configuration in QGIS 3.16

Question

How do I get the username on the current layer PostGIS in QGIS 3.16.2-Hannover? We tried examples: Getting active PostgreSQL connection username when stored through authentication configuration in QGIS 3, but they don't work.

When running this script, variable username is empty:

layer = iface.activeLayer()
provider = layer.dataProvider()
username = QgsDataSourceUri(provider.dataSourceUri()).username()
print (username)

This is result of provider.dataSourceUri()):

<QgsDataSourceUri: dbname='postgres' host= localhost port=5432 sslmode=disable key='id' srid=4326 type=Point checkPrimaryKeyUnicity='1' table="locations"."airlines" (geom)>

The value of the username is missing, the question is how to get the username for the current layer?

Answer 1

You can select your PostgreSQL user using the 'PostgreSQL Execute SQL' command in the Processing toolbox.

Query:

SELECT user;

Answer 2

Maybe this have changed since version 3.16 but in 3.32 you can simply do:

layer = iface.activeLayer()
print(layer.source())
#dbname='data' host=localhost port=5432 user='postgres' 
#sslmode=disable key='id' estimatedmetadata=true srid=3006 
#type=MultiPolygon checkPrimaryKeyUnicity='1' table="lmv"."ok_ak_riks" (geom)