[GENERAL] Table Updatable By Trigger Only

Hi All,

I have a trigger on a PostGIS table (say table A) that automatically updates another PostGIS table (say table B). Also, users connect to these tables (table A and B) using QGIS. However, I want the updates to table B to be done by the trigger only (i.e. I don't want table B to be updated from QGIS).

I have tried revoking UPDATE permissions on table B, but this prevents the trigger from updating the table also as the trigger has to work with the permissions of the user.