flask-笔记-数据库教程

数据库操作

    BASE_DIR = os.path.abspath(os.path.dirname(__file__))
    class Config(object):
    # 连接数据库
    SQLALCHEMY_DATABASE_URI = 'sqlite:///' + os.path.join(BASE_DIR, 'fk.sqlite')
    # 设置sqlalchemy 自动更新
    SQLALCHEMY_TRACK_MODIFICATIONS = True
    SQLALCHEMY_COMMIT_ON_TEARDOWN = True
    
    # 读取config对象
    app.config.form_object(Config)
    # 创建对象
    db = SQLLAlchemy(app)
    
    # 创建模型
    # 学生类
    class Student(db.Model):
        __tablename__ = 'tb_student'
        id = db.Column(db.Integer,primary_key=True,autoincrement=True)
        name = db.Column(db.String,nullable=False)
        age = db.Column(db.String(32),nullable=False)
        def __repr__(self):
            return '<obj:name:{}>'.format(self.name)
    # 老师类
    class Teacher(db.Model):
        __tablename__='tb_teacher'
        id = db.Column(db.Integer,primary_key=True,autoincrement=True)
        name = db.Column(db.String,nullable=False)
        age = db.Column(db.String(32),nullable=False)
        # 设置多对多关系
        student = db.relationship('Student',secondary=teacher_student,backref='teacher')
        def __repr__(self):
            return '<obj:name:{}>'.format(self.name)
    # 多对多关系类表
    teacher_student = bd.Table(
        'teacher_student',
        db.Column('id',db.Integer,primary_key=True,autoincrement=True)
        db.Column('teacher_id',db.Integer,db.ForeignKey='tb_teacher.id')
        db.Column('student_id',db.Integer,db.ForeignKey='tb_student.id')
    )
    # 保存到数据库
    if __name__ == '__main__':
        db.drop_all()
        db.create_all()
        # 添加数据
        stu1 = Student(name='zs',age=19)
        stu2 = Student(name='li',age=23)
        stu3 = Student(name='aa',age=34)
        tea1 = Teacher(name='lw',age=45)
        tea2 = Teacher(name='lz',age=49)
        db.session.add_all([stu1,stu2,stu3,tea1,tea2])
        db.session.commit()
        # 设置关系
        tea1.student.append(stu1)
        tea1.student.append(stu2)
        tea1.student.append(stu3)
        tea2.student.append(stu1)
        tea2.student.append(stu2)
        tea2.student.append(stu3)
        # 查询lw教的学生
        tea = Teacher.quary.filter(Teacher.name=='lw').first()
        stu = tea.student
        # 查询zs的所有老师
        stu1 = Student.query.filter(Student.name=='zs').first()
        tea1 = stu1.teacher
        # 解除lw与其学生zs的关系
        stu2 = Student.query.filter(Student.name=='zs').first()
        tea2 = Teacher.quary.filter(Teacher.name=='lw').first()
        tea2.student.remove(stu2)
        db.session.commit()

mysql数据库设置

**# mysql 8.0 需要升级SQLAlchemy至最新版**

# 1配置
    import os
    # 获取绝对路径
    BASE_DIR = os.path.abspath(os.path.dirname(__file__))

    class Config(object):
        # 连接数据库
        SQLALCHEMY_DATABASE_URI = 'mysql://root:passwrod@127.0.0.1:3306/database'
        # 设置sqlalchemy 自动更新
        SQLALCHEMY_TRACK_MODIFICATIONS = True
        SQLALCHEMY_COMMIT_ON_TEARDOWN = True

    app = Flask(__name__)
    # 读取config对象
    app.config.from_object(Config)
    
    if __name__=='__main__':
        import pymysql
        pymysql.install_as_MySQLdb()