Spring Data JPA deleteById() Method Example


In this source code example, we will demonstrate how to use the deleteById() method in Spring Data JPA to delete an entity by id from the database table.

The deleteById() method serves a simple purpose: to delete an entity based on its primary key. If you've ever found yourself writing custom deletion queries, you'll immediately see the value in this straightforward approach.

In this example, we will use the Product entity to save and delete to/from the MySQL database.

Maven Dependencies

First, you need to add the below dependencies to your Spring boot project:

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-jpa</artifactId>
		</dependency>

		<dependency>
			<groupId>com.mysql</groupId>
			<artifactId>mysql-connector-j</artifactId>
			<scope>runtime</scope>
		</dependency>

Create Product Entity

Let's first create a Product entity that we are going to save and delete to/from the MySQL database:

package net.javaguides.springdatajpacourse.entity;

import org.hibernate.annotations.CreationTimestamp;
import org.hibernate.annotations.UpdateTimestamp;

import jakarta.persistence.*;
import java.math.BigDecimal;
import java.util.Date;

@Entity
@Table(name="products")
public class Product {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;

    @Column(name = "sku")
    private String sku;

    @Column(name = "name")
    private String name;

    @Column(name = "description")
    private String description;

    @Column(name = "price")
    private BigDecimal price;

    @Column(name = "image_url")
    private String imageUrl;

    @Column(name = "active")
    private boolean active;

    @Column(name = "date_created")
    @CreationTimestamp
    private Date dateCreated;

    @Column(name = "last_updated")
    @UpdateTimestamp
    private Date lastUpdated;

    // getter and setter methods

    @Override
    public String toString() {
        return "Product{" +
                "id=" + id +
                ", sku='" + sku + '\'' +
                ", name='" + name + '\'' +
                ", description='" + description + '\'' +
                ", price=" + price +
                ", imageUrl='" + imageUrl + '\'' +
                ", active=" + active +
                ", dateCreated=" + dateCreated +
                ", lastUpdated=" + lastUpdated +
                '}';
    }
}

ProductRepository

Let's create ProductRepository which extends the JpaRepository interface:
import net.javaguides.springdatajpacourse.entity.Product;
import org.springframework.data.jpa.repository.JpaRepository;

public interface ProductRepository extends JpaRepository<Product, Long> {

}

Configure MySQL and Hibernate Properties

Let's use the MySQL database to store and retrieve the data in this example and we gonna use Hibernate properties to create and drop tables.

Open the application.properties file and add the following configuration to it:

spring.datasource.url=jdbc:mysql://localhost:3306/demo?useSSL=false
spring.datasource.username=root
spring.datasource.password=Mysql@123

spring.jpa.hibernate.ddl-auto = create-drop

spring.jpa.show-sql=true
spring.jpa.properties.hibernate.format_sql=true
Make sure that you will create a demo database before running the Spring boot application.
Also, change the MySQL username and password as per your MySQL installation on your machine.

Testing deleteById() Method

Let's write a JUnit test to test deleteById() method:

import net.javaguides.springdatajpacourse.entity.Product;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureTestDatabase;
import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;

import java.math.BigDecimal;
import java.util.List;

@DataJpaTest
@AutoConfigureTestDatabase(replace= AutoConfigureTestDatabase.Replace.NONE)
class ProductRepositoryTest {

    @Autowired
    private ProductRepository productRepository;

    protected Product getProduct1(){
        Product product = new Product();
        product.setName("product 1");
        product.setDescription("product 1 desc");
        product.setPrice(new BigDecimal(100));
        product.setSku("product 1 sku");
        product.setActive(true);
        product.setImageUrl("product1.png");
        return product;
    }

    @Test
    void testDeleteByIdMethod(){
        Product product = getProduct1();

        productRepository.save(product);

        // delete product by id
        productRepository.deleteById(product.getId());
    }
}
We are using @DataJpaTest annotation to write a JUnit test for the ProductRepository deleteById() method.

@AutoConfigureTestDatabase annotation is to disable embedded in-memory database support and enable MySQL database support.

Output

Here is the output of the above JUnit test case we wrote for testing deleteById() method:

Hibernate: 
    insert 
    into
        products
        (active, date_created, description, image_url, last_updated, name, price, sku) 
    values
        (?, ?, ?, ?, ?, ?, ?, ?)
Hibernate: 
    delete 
    from
        products 
    where
        id=?

Note that Spring Data JPA (Hibernate) produces the above SQL query delete an entity by id from the database table.

   delete 
    from
        products 
    where
        id=?

A Few Notes of Caution:

Handling Non-existent IDs: If you try to delete an entity with an ID that doesn't exist, deleteById() will throw an EmptyResultDataAccessException. It's advisable to check for the existence of the record using existsById() before calling deleteById() or handle the exception gracefully.

Transactional Integrity: Ensure that the deletion does not violate any database constraints. For instance, if there are related records in another table that depend on the record you're trying to delete, the operation will fail due to referential integrity constraints.

Cascade Deletes: If you've set up JPA cascading operations, deleting a parent entity might delete its children as well. Ensure you're aware of these cascade rules in your entity relationships.

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