我无法让我的 QSQLTableModel 连接到我的数据库，所以当我在模型上调用 select() 方法时它不会填充模型，

Question

下面的 class 是一个 QMainWindow，它旨在使用 QTableView 作为中心小部件来显示我数据库中的联系人 table，但我一直无法连接我的 QSQLTableModel 对象由于某种原因到数据库，数据库文件存储在与代码相同的位置所以我不确定我可能做错了什么

import sys
from PyQt5.QtCore import Qt
from PyQt5.QtSql import QSqlDatabase
from PyQt5.QtWidgets import QApplication
from PyQt5.QtWidgets import QLabel
from PyQt5.QtWidgets import QWidget
from PyQt5.QtWidgets import QFormLayout
from PyQt5.QtWidgets import QLineEdit
from PyQt5.QtWidgets import QMainWindow
from PyQt5.QtWidgets import QAction
from PyQt5.QtWidgets import QPushButton
from PyQt5.QtWidgets import QMenu
from PyQt5.QtSql    import  QSqlTableModel
from PyQt5.QtSql import QSqlQuery
from PyQt5.QtWidgets import QTableView

class Menu(QMainWindow):
    model = None
    con = None
    cursor = None
    def __init__(self):
        super(Menu,self).__init__()
        self.resize(415, 200)
        toolbar = self.addToolBar("Exit")
        self.model = QSqlTableModel(self)
        self.createConnection() 
        ##Here the connection is created to the database where the contatcts table is also created
        self.model.setTable("contacts") #Here i am seleecting the newly created table as the table we want to use
        print(self.con.open())
        self.model.setEditStrategy(QSqlTableModel.OnFieldChange)
        self.model.setHeaderData(0, Qt.Horizontal, "ISO_CODE")
        self.model.setHeaderData(1, Qt.Horizontal, "Location")
        self.model.setHeaderData(2, Qt.Horizontal, "Date")
        self.model.setHeaderData(3, Qt.Horizontal, "Email")
        self.model.setHeaderData(4, Qt.Horizontal, "New_cases")
        self.model.setHeaderData(3, Qt.Horizontal, "New_deaths")
        b = self.model.select() #I tried to check if the population was succesfull cause this method returns a booelean, it always returns false and i do get a blank view so i believe it does not populate the model
        print(b)
        # Set up the view
        self.view = QTableView()
        self.view.setModel(self.model)
        self.view.resizeColumnsToContents()
        self.setCentralWidget(self.view)


  def createConnection(self):
        self.con = QSqlDatabase.addDatabase("QSQLITE")
        self.con.setDatabaseName(r"C:\Users\Gabri\PycharmProjects\PyQT\recordsTest.sqlite")
        if not self.con.open():
            QMessageBox.critical(
                None,
                "QTableView Example - Error!",
                "Database Error: %s" % con.lastError().databaseText(),
            )
            sys.exit(1)
        self.cursor = QSqlQuery()
        self.cursor.exec(
            """
            CREATE TABLE contacts (
                id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE NOT NULL,
                name VARCHAR(40) NOT NULL,
                job VARCHAR(50),
                email VARCHAR(40) NOT NULL
            )
            """
        )
        print(self.con.tables())






app = QApplication(sys.argv)
win = Menu()
win.show()


sys.exit(app.exec_())

Answer 1

如果您查看 QSqlTableModel 的文档：

QSqlTableModel::QSqlTableModel(QObject *parent = nullptr, QSqlDatabase db = QSqlDatabase())
Creates an empty QSqlTableModel and sets the parent to parent and the database connection to db. If db is not valid, the default database connection will be used.

The default edit strategy is OnRowChange.

_{（强调我的）}

可以看出，如果不传递 QSqlDataBase()，它将使用现有连接，但在您的情况下它不存在，因此不会加载任何内容。解决方案是连接后创建QSqlTableModel：

self.createConnection() 
self.model = QSqlTableModel(self)

我无法让我的 QSQLTableModel 连接到我的数据库，所以当我在模型上调用 select() 方法时它不会填充模型，

I cannot get my QSQLTableModel to connect to my database, so it does not populate the model when i call the select() method on the model,

python

pyqt

python-3.x

qsqltablemodel

pyqt5