I just managed to get it working by referring to the anwer here: https://stackoverflow.com/questions/68638923/qcombobox-populated-from-a-relation-model-and-connected-to-a-qdatawidgetmapperbe
Here is my updated and working code but this seems rather complicated for what I would have guessed quite an easy task. Hopefully someone can chime in and tell me if there is a better way.
#!/usr/bin/env python3
# Ported from C++ example posted here:
# https://doc.qt.io/archives/qt-5.7/qtsql-sqlwidgetmapper-example.html
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtSql import QSqlDatabase, QSqlQuery, QSqlTableModel, QSqlRelationalTableModel, QSqlRelation, QSqlRelationalDelegate
from PyQt5.QtWidgets import QDataWidgetMapper
# import the UI generated by pyuic5
from window_ui import Ui_Dialog
# this class is a workaround for comboboxes not updating correctly with QDataWidgetMapper... i guess
# https://stackoverflow.com/questions/68638923/qcombobox-populated-from-a-relation-model-and-connected-to-a-qdatawidgetmapperbe
class Delegate(QSqlRelationalDelegate):
def setModelData(self, editor, model, index):
if isinstance(editor, QtWidgets.QComboBox):
value = editor.currentText()
if not value:
return
childModel = model.relationModel(index.column())
for column in range(2):
match = childModel.match(childModel.index(0, column),
QtCore.Qt.DisplayRole, value, QtCore.Qt.MatchStartsWith)
if match:
match = match[0]
displayValue = match.sibling(match.row(), 1).data()
editValue = match.sibling(match.row(), 0).data()
model.setData(index, displayValue, QtCore.Qt.DisplayRole)
model.setData(index, editValue, QtCore.Qt.EditRole)
return
super(Delegate, self).setModelData(editor, model, index)
class MyWindow(QtWidgets.QDialog):
def __init__(self):
super(MyWindow, self).__init__()
self.ui = Ui_Dialog()
self.ui.setupUi(self)
# setup the database connection
self.db = QSqlDatabase.addDatabase('QSQLITE')
self.db.setDatabaseName('contacts.db')
self.db.open()
# setup the model based off of an sqlite table
self.model = QSqlRelationalTableModel()
self.model.setTable('person')
self.model.setEditStrategy(QSqlTableModel.OnManualSubmit)
# setup the reference to the related lookup table
typeIndex = self.model.fieldIndex('typeindex')
self.model.setRelation(typeIndex, QSqlRelation('addressType', 'id', 'description'))
# query the db for the table -and- lookup table records
self.model.select()
# map the model's fields to the window's controls. you can use the mapper to navigate records.
self.mapper = QDataWidgetMapper()
self.mapper.setItemDelegate(Delegate())
self.mapper.setModel(self.model) #<---- needed to get combobox to work as expected with mapper & model
self.mapper.addMapping(self.ui.nameEdit, self.model.fieldIndex('name'))
self.mapper.addMapping(self.ui.addressEdit, self.model.fieldIndex('address'))
self.mapper.addMapping(self.ui.typeComboBox, typeIndex)
# setup the combobox to display the lookup table data
self.relModel = self.model.relationModel(typeIndex)
self.ui.typeComboBox.setModel(self.relModel)
self.ui.typeComboBox.setModelColumn(self.relModel.fieldIndex('description'))
# setup the events
self.ui.previousButton.clicked.connect(self.mapper.toPrevious)
self.ui.nextButton.clicked.connect(self.mapper.toNext)
self.ui.saveButton.clicked.connect(self.submit)
self.mapper.currentIndexChanged.connect(self.updateButtons)
# show the first record
self.mapper.toFirst()
def updateButtons(self, row):
self.ui.previousButton.setEnabled(row > 0)
self.ui.nextButton.setEnabled(row < self.model.rowCount() - 1)
def submit(self):
current = self.mapper.currentIndex()
self.mapper.submit()
self.model.submitAll()
self.mapper.setCurrentIndex(current)
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
win = MyWindow()
win.show()
sys.exit(app.exec())
