flask(五)orm操作及序列化/更规范的文件格式

喜欢ヅ旅行 2022-05-23 04:44 66阅读 0赞

文件树如下:  
![这里写图片描述][70]

首先是utils包:
    functions.py配置代码如下:

from flask_sqlalchemy import SQLAlchemy
    from flask_debugtoolbar import DebugToolbarExtension
    from flask_restful import Api
    from flask_marshmallow import Marshmallow
    
    db = SQLAlchemy()
    
    debugtoolbar = DebugToolbarExtension()
    
    api = Api()
    
    ma = Marshmallow()
    
    def get_db_uri(DATABASE):
    
        user = DATABASE.get('USER')
        password = DATABASE.get('PASSWORD')
        host = DATABASE.get('HOST')
        port = DATABASE.get('PORT')
        name = DATABASE.get('NAME')
        db = DATABASE.get('DB')
        driver = DATABASE.get('DRIVER')
    
    
    
        return '{}+{}://{}:{}@{}:{}/{}'.format(db, driver, user, password, host, port, name)
    
    
    def init_ext(app):
    
        # 对app进行初始化SQLALCHEMY
        db.init_app(app=app)
        # 对app进行初始化debugtoolbar
        debugtoolbar.init_app(app=app)
        # 对app进行初始化restful.Api
        api.init_app(app=app)
        # 对app进行初始化Marshmallow
        ma.init_app(app=app)

setting.py配置代码如下:

import os
    
    from utils.functions import get_db_uri
    # 基础路径
    BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
    # 页面模板
    templates_dir = os.path.join(BASE_DIR, 'templates')
    # 静态模板
    static_dir = os.path.join(BASE_DIR, 'static')
    
    DATABASE = {
        # 用户
        'USER':'root',
        # 密码
        'PASSWORD':'123456789',
        # 地址
        'HOST':'localhost',
        # 端口
        'PORT':'3306',
        # 数据库
        'DB':'mysql',
        # 驱动
        'DRIVER':'pymysql',
        # 数据表名称
        'NAME':'flask3'
    }
    
    # 以下执行的函数正确的去拼接成了flask识别的配置格式, 结果为字符串,方便给App.py里面的app.config['SQLALCHEMY_DATABASE_URI']调用
    SQLALCHEMY_DATABASE_URI = get_db_uri(DATABASE)

App.py配置代码如下:

from flask import Flask
    
    from Stu.views import stu
    from Grade.views import grade
    from utils.functions import init_ext
    
    from utils.setting import templates_dir, static_dir, SQLALCHEMY_DATABASE_URI
    
    
    def create_app():
    
    
        app = Flask(__name__,
                    template_folder=templates_dir,
                    static_folder=static_dir)
    
        app.debug = True
    
        app.register_blueprint(blueprint=stu, url_prefix='/stu')
        app.register_blueprint(blueprint=grade, url_prefix='/grade')
    
        app.config['SQLALCHEMY_DATABASE_URI'] = SQLALCHEMY_DATABASE_URI
        #上面调用函数得到的结果: app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql+pymysql://root:123456789@localhost:3306/flask3'
        app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
    
        # 配置debugtoolbar必须填写
        app.config['SECRET_KEY'] = 'secret_key'
    
        # 第一种初始化方法
        # SQLAlchemy(app=app)
    
        # 第二种初始化方法, 此方法调用函数init_ext(app)同时对app进行了SQLAlchemy和debugtoolbar的初始化
        init_ext(app)
    
        # 最重要的操作都是对app进行初始化的, db=SQLALCHEMY()这个对象并没有被改变
        return app

manage.py项目文件配置如下:

from utils.App import create_app
    from flask_script import Manager
    
    # 此为项目启动文件, 越精简越好!
    app = create_app()
    
    manage = Manager(app=app)
    
    if __name__ == '__main__':
    
        manage.run()

定义模型映射数据库:

Stu包下的models.py:

from utils.functions import db
    
    class Student(db.Model):
        s_id = db.Column(db.Integer, primary_key=True, autoincrement=True)
        s_name = db.Column(db.String(20), unique=True)
        s_age = db.Column(db.Integer, default=18)
        s_g = db.Column(db.Integer, db.ForeignKey('grade.g_id'),  nullable=True)  # 指定顺序不能混乱, 必须按照这种顺序进行参数匹配
    
    
    
        __tablename__ = 'student'
    
        def __init__(self, name, age):
    
    
            self.s_name = name
            self.s_age = age
    
    sc = db.Table('sc',
                  db.Column('s_id', db.Integer, db.ForeignKey('student.s_id'), primary_key=True),
                  db.Column('c_id', db.Integer, db.ForeignKey('course.c_id'), primary_key=True)
                  )
    
    class Course(db.Model):
    
        c_id = db.Column(db.Integer, primary_key=True, autoincrement=True)
        c_name = db.Column(db.String(10), unique=True)
        students = db.relationship('Student',
                                   secondary=sc, #定义中间表
                                   backref='course')
    
        __tablename__ = 'course'
    
        def __init__(self, name):
            self.c_name = name

Grade包下的models.py:

from datetime import datetime
    
    from utils.functions import db
    
    class Grade(db.Model):
    
        g_id = db.Column(db.Integer, primary_key=True, autoincrement=True)
        g_name = db.Column(db.String(10), unique=True)
        g_desc = db.Column(db.String(100), default=None) # 或者nullable=True
        g_time = db.Column(db.DATE, default=datetime.now())
        students = db.relationship('Student', backref='grade', lazy=True)  # 参数依次表示:模型名称, 反向加载的连接, 懒加载
    
        __tablename__ = 'grade'
    
        def __init__(self, name, desc):
    
            self.g_name = name
            self.g_desc = desc

在Stu下的 StuMarshmallow.py 进行序列化操作!

from utils.functions import ma
    
    # 序列化--->serialize
    # 自定义序列化对象
    class StuMarsh(ma.Schema):
    
        class Meta:
            # 在flask里面fields必须写!!
            fields = ['s_name', 's_age']
    
    stumarsh = StuMarsh()

Stu包下的views.py:

import random
    
    from flask import Blueprint, render_template, request, redirect, url_for
    
    # sqlalchemy里面的and_, or_, not_方法, app都是经过SQLAchemy()进行初始化的, 所以这里面的方法都能够被使用!
    from sqlalchemy import and_, or_, not_
    
    from Stu.models import Student, Course
    from utils.functions import db
    
    from flask_restful import Resource
    from utils.functions import api
    
    from Stu.StuMarshmallow import stumarsh
    
    
    stu = Blueprint('stu', __name__)    #初始化stu
    
    @stu.route('/')
    def index():
        return render_template('index.html')
    
    # 创建数据表
    @stu.route('/createdb/')
    def create_db():
        db.create_all()
        return '创建数据表成功'
    
    # 删除数据表
    @stu.route('/dropdb/')
    def drop_db():
        db.drop_all()
        return '删除数据表成功'
    
    # 创建学生信息
    @stu.route('/createstu/', methods=['GET', 'POST'])
    def create_stu():
    
        if request.method == 'GET':
    
            return render_template('create_stu.html')
    
        elif request.method == 'POST':
            username = request.form.get('username')
            age = request.form.get('age')
            stu = Student(username, age) #创建学生对象
            db.session.add(stu) # 将学生对象加入数据库中 -->缓存中
            # 处理异常
            try:
                db.session.commit() # 提交到数据库 -->执行
                return '数据库操作成功'
            except:
                db.session.rollback() # 回滚数据 -->执行
                return '数据库操作失败, 数据已经回滚'
    
    # 批量创建学生信息
    @stu.route('/createstus/', methods=['GET', 'POST'])
    def create_stus():
    
        if request.method == 'GET':
    
            return render_template('create_stus.html')
    
        elif request.method == 'POST':
            stus_list = []
    
            username1 = request.form.get('username1')
            age1 = request.form.get('age1')
    
            username2 = request.form.get('username2')
            age2 = request.form.get('age2')
    
            stu1 = Student(username1, age1)
            stu2 = Student(username2, age2)
    
            stus_list.append(stu1)
            stus_list.append(stu2)
    
            db.session.add_all(stus_list)  # 将列表里面的所有学生对象添加到缓存中 --> 缓存
    
            db.session.commit()  # 提交到数据库
    
            return '创建成功'
    
    @stu.route('/createstubyrange/')
    def create_random_stus():
        stus_list = []
        for i in range(20):
            stu = Student('小明%s' % random.randrange(1000), random.randrange(30))
            stus_list.append(stu)
        db.session.add_all(stus_list)
        db.session.commit()
        return '创建成功'
    
    
    
    @stu.route('/selectstu/')
    def select_stu():
    
        # 年龄小于16岁的学生的信息, 用逻辑运算符方法
        # stus = Student.query.filter(Student.s_age < 16)
    
        # lt le用法 小于, 小于等于
        # stus = Student.query.filter(Student.s_age.__lt__(16))
        # stus = Student.query.filter(Student.s_age.__le__(16))
    
        #gt ge 大于, 大于等于
        # stus = Student.query.filter(Student.s_age.__gt__(16))
        # stus = Student.query.filter(Student.s_age.__ge__(16))
    
        # 年龄在16, 1, 20, 34, 23, 32的学生, in_方法
        # stus = Student.query.filter(Student.s_age.in_([16, 1, 20, 34, 23, 32]))
    
        # 获取所以学生信息 用SQL语句
        # sql = 'select * from student;'
        # stus = db.session.execute(sql)
    
        # 按照id降序排列 对象.query.order_by limit取前三个 offset为跳过几个信息开始
        # stus = Student.query.order_by('-s_id').limit(3)
        # stus = Student.query.order_by('-s_age').offset(1).limit(5)
        # stus = Student.query.order_by('-s_age').offset(2)
    
        # 获取id等于24的学生
        stus = Student.query.filter(Student.s_id==24) # -->返回对象的列表, 可以迭代
        # stus = Student.query.get(24) # --> 返回具体的对象,不可迭代
    
        # 查询多个条件, and_(并且), or_(或者), not_(非,只能写一个条件)
        # stus = Student.query.filter(Student.s_age==18, Student.s_name=='小明')
        stus = Student.query.filter(and_(Student.s_age==18, Student.s_name=='小明'))
        stus = Student.query.filter(or_(Student.s_age==18, Student.s_name=='王羲之'))
        stus = Student.query.filter(not_(Student.s_age == 18), and_(Student.s_name=='王羲之'))
    
        return render_template('student_list.html', stus=stus)
    
    
    @stu.route('/stupage/')
    def stu_page():
    
        page = int(request.args.get('page', 1)) # 利用?page=2在域名上可以进行赋值
        per_page = int(request.args.get('per_page', 10))    # 每页默认10条
        print(page,per_page)
    
        paginate = Student.query.order_by('-s_id').paginate(page=page,per_page=per_page, error_out=False) # 分页器
    
        stus = paginate.items   # 获取当前分页数据
        return render_template('stupage.html', paginate=paginate, stus=stus)
    
    @stu.route('/selectgradebystu/<int:id>/')
    def select_grade_by_stu(id):
        stu = Student.query.get(id)
        grade = stu.grade
    
        return render_template('gradepage.html', stu=stu, grade=grade)
    
    @stu.route('/addcourse/')
    def add_course():
    
        courses = ['高等数学', '线性代数', '大学英语', '大学物理', 'Vfox', '毛概', '建筑设计']
        course_list = []
    
        for course in courses:
            cou = Course(course)
            course_list.append(cou)
    
        db.session.add_all(course_list)
        db.session.commit()
    
        return '添加课程成功'
    
    @stu.route('/selectcourse/', methods=['GET', 'POST']) # ---> manytomany 多对多
    def stu_cou():
        if request.method == 'GET':
            stus = Student.query.all()
            cous = Course.query.all()
            return render_template('stu_cou.html', stus=stus, cous=cous)
        if request.method == 'POST':
            # 第一种添加方式
            student_id = request.form.get('student')
            course_ids = request.form.getlist('course')
            # sql = 'insert into sc values(%s, %s)' % (student_id, course_id)
            # db.session.execute(sql)
            # db.session.commit()
    
            # 第二种添加方式
            # stu = Student.query.get(student_id)
            # cou = Course.query.get(course_id)
            # stu.course.append(cou) # 学生去查找对应的课程然后append需要添加的课程 相反也可以通过 cou去找对应的学生, 在点上对应的学生
            # db.session.add(stu) # -->可要可不要的步骤
            # db.session.commit()
    
            # 第三种添加方式, 群奶
            stu = Student.query.get(student_id)
            for course_id in course_ids:
                cou = Course.query.get(course_id)
                stu.course.append(cou)
            db.session.commit()
    
    
            return '插入成功'
    
    @stu.route('/allstu/')
    def all_stu():
    
        stus = Student.query.all()
    
        return render_template('all_stu.html', stus=stus)
    
    @stu.route('/stutocourse/<int:id>')
    def stu_to_course(id):
        stu = Student.query.get(id)
        cous = stu.course
        return render_template('stutocourse.html', cous=cous, stu=stu)
    
    @stu.route('/deletecoursebyid/<int:s_id>/<int:c_id>/')
    def delete_course_by_id(s_id, c_id):
        stu = Student.query.get(s_id)
        cou = Course.query.get(c_id)
    
        cou.students.remove(stu)
        db.session.commit()
    
        return redirect(url_for('stu.all_stu'))
    
    
    class HelloStudent(Resource):
    
        def get(self, id):
            stu = Student.query.get(id)
            # 一. 没有经过序列化的, 必须包装成字典才能够正常的去返回
            # data = { 
            # 'name':stu.s_name,
            # 'age': stu.s_age,
            #
            # }
            # return {'data': data}
    
            # 二. 经过序列化的
            return stumarsh.jsonify(stu)
    
    api.add_resource(HelloStudent, '/api/stu/<int:id>/')  # api接口访问的路由是在第二个参数, 通过这个路由去访问的返回的结果必须是json格式

Grade包下的views.py

from flask import Blueprint, render_template
    
    from utils.functions import db
    from Grade.models import Grade
    
    grade = Blueprint('grade', __name__)
    
    @grade.route('/')
    def get_grade():
    
        return 'xxxx'
    
    @grade.route('/createdb/')
    def create_db():
    
        db.create_all()
        return '创建班级成功'
    
    @grade.route('/creategrade/')
    def create_grade():
        grades = []
        dict1 = {
       'Java':'Java最牛批', 'Python':'Python最可爱', 'Html5':'Html5妹子多'}
    
        for k,v in dict1.items():
            gra1 = Grade(k, v)
            grades.append(gra1)
    
        db.session.add_all(grades)
        db.session.commit()
        return '添加成功'
    
    @grade.route('/selectstubygrade/<int:id>/')
    def select_stu_by_grade(id):
    
        grade = Grade.query.get(id)
        stus = grade.students
    
        return render_template('grade_student.html',
                               stus=stus,
                               grade=grade)

[70]: /images/20220523/8194dd77c176420f8862069d5216d0c6.png