• Add new dependencies to the project: Postgres, Spring Data JPA, and H2 embedded database.

We are going to create an ER Model for Cart Service

• ER Model
• Entity Model
• Update Flyway Scripts

Create test cases for baker controller:
Spring boot test

Configure migrations

Your new created test for JPA service is failing. It is because there are no required tables in the database, so it is time to define database schema. The reference implementation uses Flyway to automatically manage database schema. It is a very common and good practice to use any sort of schema management in the application.

• Add flyway-core dependency (using https://start.spring.io and “Explore” button if you’d like)
• Write a SQL script to create a table with the required fields, using information about entities you defined at step 2.4. Think about the primary key, is there anything in the catalog item you can use?
• Now add this script as a Flyway migration, see this page for more details.

Your test for database-backed service created at step 2.4 should now work and the whole test suite should pass.

Resources

• Flyway Discovery
• Flyway naming

We need to fix spring profile, because when starting application, spring boot is taken test profile as active.

Create a database-connected service

Spring boot JPA tests docs

Pick a right test autoconfiguration for a data JPA test
Create a new service that implements interface from step 2.2, using Spring Data repository
Now create write a test for the new service. Note that your entities (used by repository) and domain classes (used by the service) are different and service should map them.

Think why separation of database models (entities) and domain models is important? Also decide pick the right visibility level classes, which of them should be public and which private?

Your new create test should fail with an exception - there is no database schema defined yet. However now when you have all the entities defined, you can easily design your schema. We’ll do it on the next step, leave the test failing for now.

Note that you don’t need to configure database connectivity in the test, Spring Boot does that for you.