Introduction #

In the last lessons, we created both a one-to-many and a one-to-one relationship between the Employee and Department models. The code so far is given below.

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class Employee(db.Model):
    employee_id = db.Column(db.Integer, primary_key = True)
    first_name = db.Column(db.String(50), nullable = False)
    last_name = db.Column(db.String(50), nullable = False)
    department_name = db.Column(db.String, db.ForeignKey('department.name'), nullable = False)
    is_head_of = db.Column(db.String, db.ForeignKey('department.name'), nullable=True)
        
class Department(db.Model):
    name = db.Column(db.String(50), primary_key=True, nullable=False)
    location = db.Column(db.String(120), nullable=False)
    employees = db.relationship('Employee', backref='department')
    head = db.relationship('Employee', backref='head_of_department', uselist=False)
    
class Project(db.Model):
    project_id = db.Column(db.Integer, primary_key=True, nullable=False)
    name = db.Column(db.String(100), nullable=False)

Before Getting Started

Introduction to Flask

First Flask Application

Build File/Directory Explorer in Flask

Static Templates

Static Files

Dynamic Templates

Form Handling

Database

Operations on Models

Conclusion

Test a MEAN Stack Todo Application with JEST

Build an E-Learning Website Using Flask

The Many-to-Many Relationship

Introduction #

Representing a many-to-many relationship in models #