Created
April 16, 2018 16:09
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SQL Alchemy Examples With Cascade Deleting
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| from . import db | |
| # Many To Many | |
| class Exam(db.Model): | |
| __tablename__ = 'exams' | |
| score = db.Column(db.Integer, nullable=False) | |
| student_id = db.Column(db.Integer, db.ForeignKey('students.id'), primary_key=True) | |
| course_no = db.Column(db.VARCHAR(5), db.ForeignKey('courses.c_no'), primary_key=True) | |
| student = db.relationship('Student', backref=db.backref('exams', cascade='all, delete')) | |
| course = db.relationship('Course', backref=db.backref('exams', cascade='all, delete')) | |
| class Student(db.Model): | |
| __tablename__ = 'students' | |
| id = db.Column(db.Integer, primary_key=True) | |
| full_name = db.Column(db.String(64), nullable=False) | |
| class Course(db.Model): | |
| __tablename__ = 'courses' | |
| c_no = db.Column(db.VARCHAR(5), nullable=False, primary_key=True) | |
| hours = db.Column(db.Integer, nullable=False) | |
| # Many To One | |
| class User(db.Model): | |
| __tablename__ = 'users' | |
| id = db.Column(db.Integer, primary_key=True) | |
| full_name = db.Column(db.String(64), nullable=False) | |
| # addresses = db.relationship('Address', backref=db.backref('user')) | |
| class Address(db.Model): | |
| __tablename__ = 'addresses' | |
| id = db.Column(db.Integer, primary_key=True) | |
| address = db.Column(db.String(64), nullable=False) | |
| u_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False) | |
| user = db.relationship('User', backref=db.backref('addresses', cascade="all, delete")) |
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