Introduction to Relationships in TypeORM

In our virtual library, we initially stored the author as a simple string within the Book entity. However, this approach can lead to consistency and data integrity issues as the library grows. Suppose there is a mistake in an author’s name who already has multiple books in the library. Correcting this mistake requires updating the author’s name in the records of each book they have written. This process increases the risk of inconsistent data due to potential errors, such as missing some records or introducing new typos. To address this, we’ll explore relationships in TypeORM to establish a structured and reliable way to connect entities.

Defining author-book relationships

In our virtual library, each book has a single author, and each author can have multiple books, which means we have a one-to-many relationship between authors and books.

Setting up the boilerplate code

We will create a dedicated module for managing authors. To set up the necessary code for managing authors, run the following command: