使用python+pyqt+mysql编写的python三层架构项目

Python三层架构项目通常分为三个层次：表示层、业务逻辑层和数据访问层。其中表示层主要负责与用户交互，包括用户界面的设计和展示；业务逻辑层主要负责实现系统的具体业务逻辑；数据访问层主要负责与数据库进行交互，包括数据的增删改查等操作。

使用Python+PyQt+MySQL编写的三层架构项目示例代码如下：

表示层（View）：

# -*- coding: utf-8 -*-

from PyQt5.QtWidgets import QApplication, QMainWindow, QTableView
from PyQt5.QtSql import QSqlDatabase, QSqlQuery, QSqlTableModel

class MainWindow(QMainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()
        self.setWindowTitle("三层架构项目示例")

        # 连接MySQL数据库
        db = QSqlDatabase.addDatabase('QMYSQL')
        db.setHostName('localhost')
        db.setDatabaseName('test')
        db.setUserName('root')
        db.setPassword('')
        if db.open():
            print('数据库连接成功')
        else:
            print('数据库连接失败')

        # 创建数据表模型
        self.model = QSqlTableModel()
        self.model.setTable("student")
        self.model.setEditStrategy(QSqlTableModel.OnManualSubmit)
        self.model.select()

        # 创建表格视图
        self.tableView = QTableView()
        self.tableView.setModel(self.model)
        self.setCentralWidget(self.tableView)

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

业务逻辑层（Controller）：

# -*- coding: utf-8 -*-

from PyQt5.QtSql import QSqlDatabase, QSqlQuery

class StudentController:
    def __init__(self):
        # 连接MySQL数据库
        db = QSqlDatabase.addDatabase('QMYSQL')
        db.setHostName('localhost')
        db.setDatabaseName('test')
        db.setUserName('root')
        db.setPassword('')
        if db.open():
            print('数据库连接成功')
        else:
            print('数据库连接失败')

    def add_student(self, name, age):
        query = QSqlQuery()
        query.prepare("INSERT INTO student (name, age) VALUES (?, ?)")
        query.addBindValue(name)
        query.addBindValue(age)
        if query.exec_():
            print('添加学生成功')
            return True
        else:
            print('添加学生失败')
            return False

    def delete_student(self, id):
        query = QSqlQuery()
        query.prepare("DELETE FROM student WHERE id = ?")
        query.addBindValue(id)
        if query.exec_():
            print('删除学生成功')
            return True
        else:
            print('删除学生失败')
            return False

    def update_student(self, id, name, age):
        query = QSqlQuery()
        query.prepare("UPDATE student SET name = ?, age = ? WHERE id = ?")
        query.addBindValue(name)
        query.addBindValue(age)
        query.addBindValue(id)
        if query.exec_():
            print('更新学生成功')
            return True
        else:
            print('更新学生失败')
            return False

    def get_student_list(self):
        query = QSqlQuery()
        query.exec_("SELECT * FROM student")
        student_list = []
        while query.next():
            student = {
                'id': query.value(0),
                'name': query.value(1),
                'age': query.value(2)
            }
            student_list.append(student)
        return student_list

数据访问层（Model）：

# -*- coding: utf-8 -*-

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String

Base = declarative_base()

class Student(Base):
    __tablename__ = 'student'

    id = Column(Integer, primary_key=True)
    name = Column(String(50), nullable=False)
    age = Column(Integer, nullable=False)

class StudentModel:
    def __init__(self):
        # 连接MySQL数据库
        engine = create_engine('mysql://root:@localhost/test?charset=utf8')
        Session = sessionmaker(bind=engine)
        self.session = Session()

    def add_student(self, name, age):
        student = Student(name=name, age=age)
        self.session.add(student)
        self.session.commit()

    def delete_student(self, id):
        student = self.session.query(Student).filter_by(id=id).first()
        self.session.delete(student)
        self.session.commit()

    def update_student(self, id, name, age):
        student = self.session.query(Student).filter_by(id=id).first()
        student.name = name
        student.age = age
        self.session.commit()

    def get_student_list(self):
        student_list = []
        for student in self.session.query(Student).all():
            student_dict = {
                'id': student.id,
                'name': student.name,
                'age': student.age
            }
            student_list.append(student_dict)
        return student_list

通过以上示例代码，我们可以实现一个简单的Python三层架构项目，并且可以实现基本的数据的增删改查操作。