This section describes the various association types in Sequelize. When calling a method such as User.hasOne(Project), we say that the User model (the model that the function is being invoked on) is the source and the Project model (the model being passed as an argument) is the target.
Database design is the organization of data according to a database model. The designer determines what data must be stored and how the data elements interrelate. With this information, they can begin to fit the data to the database model. Database design involves classifying data and identifying interrelationships.
With PostgreSQL as our object-relational database management system (ORDBMS) and Sequelize as our library of choice to implement object-relational mapping (ORM), we will be covering the bases when it comes to the associations, or relationships, that exist among the various table