PyQt5下拉框连接数据库

下面是一个简单的教程，展示如何在PyQt5中使用下拉框连接数据库：

1. 导入必要的库

from PyQt5.QtWidgets import QApplication, QWidget, QComboBox
from PyQt5.QtSql import QSqlDatabase, QSqlQueryModel

2. 创建一个QWidget窗口和一个下拉框QComboBox

class MyWidget(QWidget):
    def __init__(self):
        super().__init__()
        self.combo = QComboBox(self)

3. 连接到数据库

def connect_to_database(self):
    db = QSqlDatabase.addDatabase('QSQLITE')
    db.setDatabaseName('mydatabase.db')
    if not db.open():
        print("Cannot establish a database connection")
        return False
    else:
        print("Database connection established successfully")
        return True

4. 将数据库中的数据填充到下拉框中

def fill_combo(self):
    query_model = QSqlQueryModel()
    query_model.setQuery("SELECT name FROM mytable")
    self.combo.setModel(query_model)

5. 将下拉框添加到QWidget中并显示

self.fill_combo()
self.show()

完整代码如下所示：

from PyQt5.QtWidgets import QApplication, QWidget, QComboBox
from PyQt5.QtSql import QSqlDatabase, QSqlQueryModel


class MyWidget(QWidget):
    def __init__(self):
        super().__init__()
        self.combo = QComboBox(self)
        self.connect_to_database()
        self.fill_combo()
        self.show()

    def connect_to_database(self):
        db = QSqlDatabase.addDatabase('QSQLITE')
        db.setDatabaseName('mydatabase.db')
        if not db.open():
            print("Cannot establish a database connection")
            return False
        else:
            print("Database connection established successfully")
            return True

    def fill_combo(self):
        query_model = QSqlQueryModel()
        query_model.setQuery("SELECT name FROM mytable")
        self.combo.setModel(query_model)


if __name__ == '__main__':
    app = QApplication([])
    widget = MyWidget()
    app.exec_()