Мини автономная БД

import sys
from PyQt5.QtWidgets import QApplication, QTableView, QWidget, QVBoxLayout, QPushButton
from PyQt5.QtWidgets import QDialog, QLabel, QGridLayout, QLineEdit, QComboBox
from PyQt5.QtSql     import QSqlDatabase, QSqlQuery, QSqlTableModel
from PyQt5.QtSql     import QSqlRelationalTableModel, QSqlRelation
from PyQt5.QtCore    import Qt, QRegExp
from PyQt5.QtGui     import QRegExpValidator
 
class NewRecord(QDialog):
  def __init__(self, parent):
    super().__init__(parent)
    button = QPushButton("добавть")
    button.clicked.connect(self.write)
    self.name = QLineEdit()
    self.phone = QLineEdit()
    validator = QRegExpValidator(QRegExp("^\\+7[0-9]+"))
    self.phone.setValidator(validator)
    self.address = QLineEdit()
    self.spec = QComboBox()
    model = QSqlTableModel()
    model.setTable("specs")
    model.select()
    self.spec.setModel(model)
    self.spec.setModelColumn(1)
    l1 = QVBoxLayout()
    l2 = QGridLayout()
    l2.addWidget(QLabel("ФИО"),0,0)
    l2.addWidget(QLabel("телефон"),1,0)
    l2.addWidget(QLabel("адрес"),2,0)
    l2.addWidget(QLabel("специальность"),3,0)
    l2.addWidget(self.name, 0, 1)
    l2.addWidget(self.phone, 1, 1)
    l2.addWidget(self.address, 2, 1)
    l2.addWidget(self.spec, 3, 1)
    l1.addLayout(l2)
    l1.addWidget(button)
    self.setLayout(l1)
  def write(self):
    query = QSqlQuery()
    query.prepare("INSERT INTO abiturient"
                  "(name, phone, address, spec)"
                  "VALUES (:name, :phone, :address, :spec);")
    query.bindValue(":name", self.name.text())
    query.bindValue(":phone", self.phone.text())
    query.bindValue(":address", self.address.text())
    query.bindValue(":spec", self.spec.model().index(self.spec.currentIndex(),0).data())
    query.exec_()
    self.accept()
 
class Window(QWidget):
  def __init__(self):
    super().__init__(None)
    self.model = QSqlRelationalTableModel()
    self.model.setTable("abiturient")
    self.model.setRelation(4, QSqlRelation("specs", "id", "name"))
    self.model.select()
    def flags(index):
      return Qt.ItemIsEnabled | Qt.ItemIsSelectable
    self.model.flags = flags
    table = QTableView()
    table.setModel(self.model)
    table.setColumnHidden(0, True)
    self.model.setHeaderData(1, Qt.Horizontal, "ФИО")
    self.model.setHeaderData(2, Qt.Horizontal, "телефон")
    self.model.setHeaderData(3, Qt.Horizontal, "адрес")
    self.model.setHeaderData(4, Qt.Horizontal, "специальность")
    button = QPushButton("добавить абитуриента")
    button.clicked.connect(self.addRecord)
    layout = QVBoxLayout()
    layout.addWidget(table)
    layout.addWidget(button)
    self.setLayout(layout)
  def addRecord(self):
    record = NewRecord(self)
    if record.exec_():
      self.model.select()
 
app = QApplication(sys.argv)
db = QSqlDatabase.addDatabase("QSQLITE")
db.setDatabaseName(":memory:")
db.open()
query = QSqlQuery(db)
query.exec_("PRAGMA foreign_keys = ON;")
query.exec_("CREATE TABLE specs (id INTEGER PRIMARY KEY, name TEXT);")
query.exec_("CREATE TABLE abiturient (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, phone TEXT, address TEXT, spec INT,"
            "FOREIGN KEY(spec) REFERENCES specs(id));")
query.exec_("INSERT INTO specs (id, name) VALUES (10, 'spec0');")
query.exec_("INSERT INTO specs (id, name) VALUES (20, 'spec1');")
query.exec_("INSERT INTO specs (id, name) VALUES (30, 'spec2');")
query.exec_("INSERT INTO abiturient (name, phone, address, spec) VALUES ('name', '+7....', 'address', 10);")
window = Window()
window.show()
sys.exit(app.exec_())