Question

I got a toy phonebook application used to learn PySide:

import sys
import os

from PySide import QtCore, QtGui, QtSql

import phonebook_ui


CURRENT_FILE = os.path.abspath(__file__)
CURRENT_DIR = os.path.dirname(CURRENT_FILE)
DB_PATH = os.path.join(CURRENT_DIR, 'db.sqlite')

class PhoneBook(QtGui.QMainWindow, phonebook_ui.Ui_MainWindow):

    def __init__(self):
        super(PhoneBook, self).__init__()
        self.setupUi(self)
        self.db = self.create_connection()

        # this is where the two tables should me linked automatically
        self.model = QtSql.QSqlRelationalTableModel(self)
        self.model.setTable('person')
        self.model.setEditStrategy(QtSql.QSqlRelationalTableModel.OnManualSubmit)
        foreign_key = self.model.fieldIndex('service')
        self.model.setRelation(foreign_key, 
                               QtSql.QSqlRelation("service", "id", "nom"))
        self.model.select()

        self.relation_model = self.model.relationModel(foreign_key)
        self.edit_service.setModel(self.relation_model)
        self.edit_service.setModelColumn(self.relation_model.fieldIndex("name"))

        self.listing.setModel(self.model)
        self.listing.setColumnHidden(0, True)
        self.listing.setSelectionMode(QtGui.QAbstractItemView.SelectionMode.SingleSelection)

        # this is where the model data should be automatically injected in the
        # central table
        self.mapper = QtGui.QDataWidgetMapper(self)
        self.mapper.setModel(self.model)
        self.mapper.setItemDelegate(QtSql.QSqlRelationalDelegate(self))
        self.mapper.addMapping(self.edit_name, self.model.fieldIndex('name'))
        self.mapper.addMapping(self.edit_phone, self.model.fieldIndex('phone'))
        self.mapper.addMapping(self.edit_service, foreign_key)

        self.listing.selectionChanged = self.on_selection_changed



    def on_selection_changed(self, selected, deselected):
        range = selected[0]
        index = range.indexes()[0]
        self.mapper.setCurrentIndex(index.row())

    @classmethod
    def create_connection(cls, bdd=DB_PATH):
        db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
        db.setDatabaseName(bdd)
        db.open()
        query = QtSql.QSqlQuery()
        query.exec_(u"create table person(id int primary key, name varchar(20), "
                    u"phone varchar(20), service varchar(20))")    
        db.commit()
        return db

    def close(self):
        super(PhoneBook, self).close()
        self.db.close()


if __name__ == '__main__':

    app = QtGui.QApplication(sys.argv)
    phonebook = PhoneBook()
    phonebook.show()
    sys.exit(app.exec_())

Here is a screenshot:

My tables look like this:

I managed to make it work once with no service field, but now that I added it, I introduced the notion of QSqlRelationalTableModel and failed to make it work.

What’s it’s supposed to do:

• fill the big white central table with a listing of people from the DB (fails, despite the model and mapper being setup and the db containing 2 entries)
• on click on any of the central table rows, fill the bottom form with the row data
• allow edit and save.

The DB is filled up with data and is readable from my tests in the python shell.

The code throw no errors, but nothing happens: the windows is displayed with nothing in there.

Can you point my mistakes here ?

I’ll be happy to provide any additional information you need

Answer 1

In code you have service varchar(20)), but in screenshot, service is a separate table (as it should be). But I see nom instead name on screenshot (QtSql.QSqlRelation("service", "id", "name")).

So, if you’ll check your database schema and actualize it with code, it should work.

@classmethod
def create_connection(cls, bdd=DB_PATH):
    db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
    db.setDatabaseName(bdd)
    db.open()
    query = QtSql.QSqlQuery()
    query.exec_(u"create table person(id int primary key, name varchar(20), "
                u"phone varchar(20), service int)")    

    query.exec_(u"create table service(id int primary key, name varchar(20))")  
    db.commit()
    return db  # don't forget to return it, as you use it in close

P.S. I have not checked “edit” and “add” logic.