pyqt5创建可以增删改查的数据库的界面的代码

非常感谢您的提问。以下是使用PyQt5创建可以增删改查的数据库界面的代码：

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QTableWidgetItem, QVBoxLayout, QHBoxLayout, QWidget, QLabel, QLineEdit, QPushButton, QTableWidget, QMessageBox
from PyQt5.QtSql import QSqlDatabase, QSqlQuery, QSqlTableModel


class ContactsWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        # 设置窗口的标题和大小
        self.setWindowTitle("联系人管理系统")
        self.setMinimumSize(800, 600)

        # 创建数据库连接
        self.db = QSqlDatabase.addDatabase("QSQLITE")
        self.db.setDatabaseName("contacts.db")
        if not self.db.open():
            QMessageBox.critical(None, "无法打开数据库", "无法连接数据库，添加联系人功能无法使用")
            return

        # 创建“联系人”表
        query = QSqlQuery()
        query.exec_(
            "CREATE TABLE IF NOT EXISTS contacts (id INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR(40), phone VARCHAR(12), email VARCHAR(40))")

        # 创建左侧的表格
        self.table = QTableWidget(self)
        self.table.setColumnCount(4)
        self.table.setHorizontalHeaderLabels(["ID", "姓名", "手机", "邮箱"])
        self.table.verticalHeader().setVisible(False)
        self.load_contacts()

        # 创建右侧的表单
        self.name_label = QLabel("姓名：")
        self.name_input = QLineEdit()
        self.phone_label = QLabel("手机：")
        self.phone_input = QLineEdit()
        self.email_label = QLabel("邮箱：")
        self.email_input = QLineEdit()
        self.add_button = QPushButton("添加")
        self.add_button.clicked.connect(self.add_contact)
        self.update_button = QPushButton("更新")
        self.update_button.clicked.connect(self.update_contact)
        self.delete_button = QPushButton("删除")
        self.delete_button.clicked.connect(self.delete_contact)
        form_layout = QVBoxLayout()
        form_layout.addWidget(self.name_label)
        form_layout.addWidget(self.name_input)
        form_layout.addWidget(self.phone_label)
        form_layout.addWidget(self.phone_input)
        form_layout.addWidget(self.email_label)
        form_layout.addWidget(self.email_input)
        form_layout.addWidget(self.add_button)
        form_layout.addWidget(self.update_button)
        form_layout.addWidget(self.delete_button)
        form_widget = QWidget()
        form_widget.setLayout(form_layout)

        # 把左侧的表格和右侧的表单放到一个水平布局中
        hbox = QHBoxLayout()
        hbox.addWidget(self.table)
        hbox.addWidget(form_widget)

        # 把水平布局放到窗口中
        central_widget = QWidget()
        central_widget.setLayout(hbox)
        self.setCentralWidget(central_widget)

    # 从数据库中读取所有联系人信息，并显示在左侧的表格中
    def load_contacts(self):
        query = QSqlQuery()
        query.exec_("SELECT * FROM contacts")
        row = 0
        while query.next():
            self.table.insertRow(row)
            self.table.setItem(row, 0, QTableWidgetItem(str(query.value(0))))
            self.table.setItem(row, 1, QTableWidgetItem(str(query.value(1))))
            self.table.setItem(row, 2, QTableWidgetItem(str(query.value(2))))
            self.table.setItem(row, 3, QTableWidgetItem(str(query.value(3))))
            row += 1

    # 添加联系人
    def add_contact(self):
        name = self.name_input.text().strip()
        phone = self.phone_input.text().strip()
        email = self.email_input.text().strip()
        if not name or not phone:
            QMessageBox.warning(self, "警告", "姓名和手机不能为空")
            return
        query = QSqlQuery()
        query.prepare("INSERT INTO contacts(name, phone, email) VALUES (:name, :phone, :email)")
        query.bindValue(":name", name)
        query.bindValue(":phone", phone)
        query.bindValue(":email", email)
        if query.exec_():
            row = self.table.rowCount()
            self.table.insertRow(row)
            self.table.setItem(row, 0, QTableWidgetItem(str(query.lastInsertId())))
            self.table.setItem(row, 1, QTableWidgetItem(name))
            self.table.setItem(row, 2, QTableWidgetItem(phone))
            self.table.setItem(row, 3, QTableWidgetItem(email))
            self.name_input.setText("")
            self.phone_input.setText("")
            self.email_input.setText("")
        else:
            QMessageBox.critical(self, "添加联系人错误", "无法添加联系人")

    # 更新联系人
    def update_contact(self):
        cur_row = self.table.currentRow()
        if cur_row < 0:
            QMessageBox.warning(self, "警告", "请先选择要更新的联系人")
            return
        id = int(self.table.item(cur_row, 0).text())
        name = self.name_input.text().strip()
        phone = self.phone_input.text().strip()
        email = self.email_input.text().strip()
        if not name or not phone:
            QMessageBox.warning(self, "警告", "姓名和手机不能为空")
            return
        query = QSqlQuery()
        query.prepare("UPDATE contacts SET name=:name, phone=:phone, email=:email WHERE id=:id")
        query.bindValue(":name", name)
        query.bindValue(":phone", phone)
        query.bindValue(":email", email)
        query.bindValue(":id", id)
        if query.exec_():
            self.table.setItem(cur_row, 1, QTableWidgetItem(name))
            self.table.setItem(cur_row, 2, QTableWidgetItem(phone))
            self.table.setItem(cur_row, 3, QTableWidgetItem(email))
            self.name_input.setText("")
            self.phone_input.setText("")
            self.email_input.setText("")
        else:
            QMessageBox.critical(self, "更新联系人错误", "无法更新联系人")

    # 删除联系人
    def delete_contact(self):
        cur_row = self.table.currentRow()
        if cur_row < 0:
            QMessageBox.warning(self, "警告", "请先选择要删除的联系人")
            return
        id = int(self.table.item(cur_row, 0).text())
        query = QSqlQuery()
        query.prepare("DELETE FROM contacts WHERE id=:id")
        query.bindValue(":id", id)
        if query.exec_():
            self.table.removeRow(cur_row)
        else:
            QMessageBox.critical(self, "删除联系人错误", "无法删除联系人")


if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = ContactsWindow()
    window.show()
    sys.exit(app.exec_())

注意需要安装PyQt5和PyQt5-sqlite插件，以及SQLite数据库。

我希望这段代码能够解决您的问题。如果您有任何其他问题，请随时提出。