PyQt5+MySQL+PyMySQL模块实现个简单的增删改查，代码示例

### 回答1：
以下是一个简单的 PyQt5 MySQL PyMySQL 模块实现增删改查的示例代码：

import pymysql
from PyQt5.QtWidgets import QApplication, QWidget, QLabel, QLineEdit, QPushButton, QVBoxLayout, QHBoxLayout, QMessageBox, QTableWidget, QTableWidgetItem

class Example(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setWindowTitle('PyQt5 MySQL PyMySQL')
        self.setGeometry(300, 300, 500, 500)

        # 连接 MySQL 数据库
        self.conn = pymysql.connect(host='localhost', user='root', password='password', database='test', charset='utf8')
        self.cursor = self.conn.cursor()

        # 创建控件
        self.label1 = QLabel('姓名')
        self.label2 = QLabel('年龄')
        self.label3 = QLabel('性别')
        self.nameEdit = QLineEdit()
        self.ageEdit = QLineEdit()
        self.genderEdit = QLineEdit()
        self.addButton = QPushButton('添加')
        self.deleteButton = QPushButton('删除')
        self.updateButton = QPushButton('更新')
        self.queryButton = QPushButton('查询')
        self.tableWidget = QTableWidget()

        # 布局
        hbox1 = QHBoxLayout()
        hbox1.addWidget(self.label1)
        hbox1.addWidget(self.nameEdit)
        hbox1.addWidget(self.label2)
        hbox1.addWidget(self.ageEdit)
        hbox1.addWidget(self.label3)
        hbox1.addWidget(self.genderEdit)

        hbox2 = QHBoxLayout()
        hbox2.addWidget(self.addButton)
        hbox2.addWidget(self.deleteButton)
        hbox2.addWidget(self.updateButton)
        hbox2.addWidget(self.queryButton)

        vbox = QVBoxLayout()
        vbox.addLayout(hbox1)
        vbox.addLayout(hbox2)
        vbox.addWidget(self.tableWidget)

        self.setLayout(vbox)

        # 信号槽连接
        self.addButton.clicked.connect(self.addRecord)
        self.deleteButton.clicked.connect(self.deleteRecord)
        self.updateButton.clicked.connect(self.updateRecord)
        self.queryButton.clicked.connect(self.queryRecord)

        # 显示窗口
        self.show()

    def addRecord(self):
        name = self.nameEdit.text()
        age = self.ageEdit.text()
        gender = self.genderEdit.text()
        if name and age and gender:
            sql = "INSERT INTO students (name, age, gender) VALUES ('{}', {}, '{}')".format(name, age, gender)
            try:
                self.cursor.execute(sql)
                self.conn.commit()
                QMessageBox.information(self, '添加成功', '添加记录成功！')
            except Exception as e:
                self.conn.rollback()
                QMessageBox.warning(self, '添加失败', '添加记录失败：{}'.format(str(e)))
        else:
            QMessageBox.warning(self, '添加失败', '请填写完整信息！')

    def deleteRecord(self):
        row = self.tableWidget.currentRow()
        if row >= :
            id = self.tableWidget.item(row, ).text()
            sql = "DELETE FROM students WHERE id = {}".format(id)
            try:
                self.cursor.execute(sql)
                self.conn.commit()
                self.tableWidget.removeRow(row)
                QMessageBox.information(self, '删除成功', '删除记录成功！')
            except Exception as e:
                self.conn.rollback()
                QMessageBox.warning(self, '删除失败', '删除记录失败：{}'.format(str(e)))
        else:
            QMessageBox.warning(self, '删除失败', '请选择要删除的记录！')

    def updateRecord(self):
        row = self.tableWidget.currentRow()
        if row >= :
            id = self.tableWidget.item(row, ).text()
            name = self.nameEdit.text()
            age = self.ageEdit.text()
            gender = self.genderEdit.text()
            if name and age and gender:
                sql = "UPDATE students SET name = '{}', age = {}, gender = '{}' WHERE id = {}".format(name, age, gender, id)
                try:
                    self.cursor.execute(sql)
                    self.conn.commit()
                    self.tableWidget.setItem(row, 1, QTableWidgetItem(name))
                    self.tableWidget.setItem(row, 2, QTableWidgetItem(age))
                    self.tableWidget.setItem(row, 3, QTableWidgetItem(gender))
                    QMessageBox.information(self, '更新成功', '更新记录成功！')
                except Exception as e:
                    self.conn.rollback()
                    QMessageBox.warning(self, '更新失败', '更新记录失败：{}'.format(str(e)))
            else:
                QMessageBox.warning(self, '更新失败', '请填写完整信息！')
        else:
            QMessageBox.warning(self, '更新失败', '请选择要更新的记录！')

    def queryRecord(self):
        self.tableWidget.clear()
        self.tableWidget.setColumnCount(4)
        self.tableWidget.setHorizontalHeaderLabels(['ID', '姓名', '年龄', '性别'])
        sql = "SELECT * FROM students"
        try:
            self.cursor.execute(sql)
            results = self.cursor.fetchall()
            self.tableWidget.setRowCount(len(results))
            for i, row in enumerate(results):
                for j, col in enumerate(row):
                    self.tableWidget.setItem(i, j, QTableWidgetItem(str(col)))
        except Exception as e:
            QMessageBox.warning(self, '查询失败', '查询记录失败：{}'.format(str(e)))

    def closeEvent(self, event):
        self.cursor.close()
        self.conn.close()

if __name__ == '__main__':
    app = QApplication([])
    ex = Example()
    app.exec_()

注意：这只是一个简单的示例代码，实际应用中需要根据具体情况进行修改和优化。

### 回答2：
使用PyQt5和PyMySQL模块实现一个简单的增删改查操作，以下是代码示例：

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QWidget, QVBoxLayout, QHBoxLayout, QLabel, QLineEdit, QPushButton, QMessageBox, QTableWidgetItem, QTableWidget
import pymysql

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initUI()
        self.db = pymysql.connect("localhost", "username", "password", "database_name")
        self.cursor = self.db.cursor()

    def initUI(self):
        self.setWindowTitle("简单的增删改查")
        self.setGeometry(300, 300, 500, 350)

        self.centralWidget = QWidget(self)
        self.setCentralWidget(self.centralWidget)

        self.layout = QVBoxLayout()
        self.centralWidget.setLayout(self.layout)

        self.inputLayout = QHBoxLayout()
        self.layout.addLayout(self.inputLayout)

        self.nameLabel = QLabel("姓名:")
        self.inputLayout.addWidget(self.nameLabel)
        self.nameInput = QLineEdit()
        self.inputLayout.addWidget(self.nameInput)

        self.addButton = QPushButton("添加")
        self.addButton.clicked.connect(self.addRecord)
        self.layout.addWidget(self.addButton)

        self.tableWidget = QTableWidget()
        self.layout.addWidget(self.tableWidget)

        self.loadTable()

    def loadTable(self):
        self.cursor.execute("SELECT * FROM students")
        results = self.cursor.fetchall()
        self.tableWidget.setRowCount(len(results))
        self.tableWidget.setColumnCount(2)

        self.tableWidget.setHorizontalHeaderLabels(["ID", "姓名"])

        for i, row in enumerate(results):
            for j, value in enumerate(row):
                self.tableWidget.setItem(i, j, QTableWidgetItem(str(value)))

    def addRecord(self):
        name = self.nameInput.text()
        if name:
            sql = "INSERT INTO students (name) VALUES ('%s')" % name
            try:
                self.cursor.execute(sql)
                self.db.commit()
                self.nameInput.clear()
                self.loadTable()
            except:
                self.db.rollback()
                QMessageBox.warning(self, "Error", "添加记录失败")
        else:
            QMessageBox.warning(self, "Error", "姓名不能为空")

    def closeEvent(self, event):
        self.cursor.close()
        self.db.close()

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

上述代码实现了一个简单的GUI界面，包含一个用于输入姓名的文本框和一个用于添加记录的按钮。数据存储在MySQL数据库的`students`表中，其中包含`id`和`name`两个字段。点击添加按钮后将会将姓名插入到数据库中，并更新显示在表格中。表格使用QTableWidget来显示。通过`PyMySQL`模块连接和操作数据库。

### 回答3：
以下是使用PyQt5和PyMySQL模块实现简单的增删改查的代码示例：

import pymysql
from PyQt5.QtWidgets import QApplication, QMainWindow, QTableWidget, QTableWidgetItem, QPushButton, QVBoxLayout, QWidget

class DatabaseWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("数据库操作")
        self.setGeometry(100, 100, 400, 300)

        self.table_widget = QTableWidget()
        self.setCentralWidget(self.table_widget)

        self.btn_refresh = QPushButton("刷新")
        self.btn_refresh.clicked.connect(self.refresh_data)
        self.btn_add = QPushButton("添加")
        self.btn_add.clicked.connect(self.add_data)
        self.btn_delete = QPushButton("删除")
        self.btn_delete.clicked.connect(self.delete_data)
        self.btn_update = QPushButton("更新")
        self.btn_update.clicked.connect(self.update_data)

        layout = QVBoxLayout()
        layout.addWidget(self.btn_refresh)
        layout.addWidget(self.btn_add)
        layout.addWidget(self.btn_delete)
        layout.addWidget(self.btn_update)

        widget = QWidget()
        widget.setLayout(layout)
        self.setCentralWidget(widget)

        self.db = pymysql.connect(host='localhost', user='root', password='password', db='testdb')
        self.cursor = self.db.cursor()

        self.refresh_data()

    def refresh_data(self):
        self.table_widget.clear()
        self.cursor.execute("SELECT * FROM users")
        data = self.cursor.fetchall()
        self.table_widget.setRowCount(len(data))
        self.table_widget.setColumnCount(len(data[0]))

        for i, row in enumerate(data):
            for j, value in enumerate(row):
                item = QTableWidgetItem(str(value))
                self.table_widget.setItem(i, j, item)

    def add_data(self):
        self.cursor.execute("INSERT INTO users (name, age) VALUES ('John', 30)")
        self.db.commit()
        self.refresh_data()

    def delete_data(self):
        selected_row = self.table_widget.currentRow()
        id = self.table_widget.item(selected_row, 0).text()

        self.cursor.execute(f"DELETE FROM users WHERE id={id}")
        self.db.commit()
        self.refresh_data()

    def update_data(self):
        selected_row = self.table_widget.currentRow()
        id = self.table_widget.item(selected_row, 0).text()

        self.cursor.execute(f"UPDATE users SET name='Mike', age=25 WHERE id={id}")
        self.db.commit()
        self.refresh_data()

if __name__ == '__main__':
    app = QApplication([])
    window = DatabaseWindow()
    window.show()
    app.exec_()

此示例展示了一个使用PyQt5和PyMySQL模块实现的简单的数据库操作窗口。窗口中包含一个表格用于显示数据库中的数据。通过点击不同按钮，可以刷新数据，添加数据，删除数据和更新数据。代码中的数据库连接参数需要根据实际情况进行修改。