The One-to-Many Relationship

Introduction #

While working with databases, one of the key concepts is the relationship between tables. The types of relationships that exist are:

• One-to-many
• One-to-one
• Many-to-many

In the next few lessons, we will cover how to represent and create these relationships between the models using SQLAlchemy.

Consider the Human Resource Management System(HRMS) of a company. The application would contain the following models.

• Employee
• Department
• Project

A simple implementation of these models is given below.