PyQGIS - Adding layer from PostGis database and work with it in QGIS interface

Question

I try to add from my db postgis to my QGIS interface a table, I'm using a script with the good parameters. But my problem is when I run my function my QGIS bugs and close.

from qgis.core import *
from qgis.core import QgsProject
from PyQt5.QtCore import QFileInfo
from qgis.core import QgsVectorLayer, QgsDataSourceUri
from qgis.utils import *

def run_script(iface):
   uri = QgsDataSourceUri()
   uri.setConnection("localhost", "5432", "Base_test", "user", "passeword")
   uri.setDataSource("public", "BPE", "geom")

   layer = QgsVectorLayer(uri.uri(), "bpe", "user")
   if not layer.isValide():
       print("Layer %s did not load" %layer.name())  
   QgsProject.instance().addMapLayer(layer)

it say me that the layer did not load. and QGIS need to be restarted after that.

can someone help me please.

I'm using QGIS 3.10

Answer 1

Try this code:

   from qgis.core import *
   from qgis.core import QgsProject
   from PyQt5.QtCore import QFileInfo
   from qgis.core import QgsVectorLayer, 
   QgsDataSourceUri
   from qgis.utils import *  

   def run_script(iface):
   uri = QgsDataSourceUri()
   uri.setConnection("localhost", "5432", "Base_test", 
   "user", "passeword")
   uri.setDataSource("public", "BPE", "geom")

   layer = QgsVectorLayer(uri.uri(), "bpe", "postgres")
   if not layer.isValid():
       print("Layer %s did not load" %layer.name())  
   QgsProject.instance().addMapLayer(layer)

   run_script()

1. You made a spelling mistake:if not layer.isValide()-->if notlayer.isValid()
2. You need to specify the provider (postgres in this case) layer = QgsVectorLayer(uri.uri(), "bpe", "user")--> layer=QgsVectorLayer(uri.uri(), "bpe", "postgres")
3. Run/Call the function (you just defined it): run_script()

Check the Documentation: https://qgis.org/pyqgis/3.0/core/Vector/QgsVectorLayer.html

Cheers