Creating CRUD repositories

The Spring Boot Data JPA provides a CrudRepository interface for Create, Read, Update, and Delete (CRUD) operations. It provides CRUD functionalities to our entity class.Let's create our repository in the domain package, as follows:

1. Create a new interface called CarRepository in the com.packt.cardatabase.domain package and modify the file according to the following code snippet:

package com.packt.cardatabase.domain;
import org.springframework.data.repository
.CrudRepository;
public interface CarRepository extends CrudRepository<Car, Long> {
}

CarRepository now extends the Spring Boot JPA CrudRepository interface. The <Car, Long> type arguments define that this is the repository for the Car entity class and that the type of the ID field is Long.The CrudRepository interface provides multiple CRUD methods that we can now start to use. The following table lists the most commonly used methods:

Table 3.1: CRUD methods

If the method returns only...