code: def updateJoin(self):
          
          text = self.uiJoinSBTN.currentAction().text()
          if text == 'AND':
              joiner = QueryCompound.Op.And
          else:
              joiner = QueryCompound.Op.Or
          
          self._containerWidget.setCurrentJoiner(self.joiner())
docs: Updates the joining method used by the system.