Spring Data JPA - save() Method Example


Spring Data JPA - save() Method Spring Data JPA - saveAll() Method Spring Data JPA - findById() Method Spring Data JPA - findAll() Method Spring Data JPA - count() Method Spring Data JPA - deleteById() Method Spring Data JPA - delete() Method Spring Data JPA - deleteAll() Method Spring Data JPA - Distinct Query Method Spring Data JPA - GreaterThan Query Method Spring Data JPA - LessThan Query Method Spring Data JPA - Containing Query Method Spring Data JPA - Like Query Method Spring Data JPA - Between Query Method Spring Data JPA - Date Range Between Query Method Spring Data JPA - In Clause Query Method


In this source code example, we will demonstrate how to use the save() method in Spring Data JPA to save an entity.

In this example, we will use the Product entity to save into 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>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>

Create Product Entity

Let's first create a Product entity that we are going to save into the database using the save() method:

package net.javaguides.springdatajpacourse.entity;

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

import javax.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.properties.hibernate.dialect = org.hibernate.dialect.MySQL5InnoDBDialect

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 save() Method

Let's write a JUnit test to test saving Product entity into the MySQL database:

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;


    @Test
    void testSaveMethod() throws InterruptedException {
        Product product = getProduct1();

        // save product
        productRepository.save(product);
    }

    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;
    }
}

We are using @DataJpaTest annotation to write a JUnit test ProductRepository save() 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 save() method:

Hibernate: 
    insert 
    into
        products
        (active, date_created, description, image_url, last_updated, name, price, sku) 
    values
        (?, ?, ?, ?, ?, ?, ?, ?)
Note that Spring Data JPA (Hibernate) produces the above SQL query to save the Product entity into the database table. 

Free Spring Boot Tutorial - 5 Hours Full Course

Watch this course on YouTube at Spring Boot Tutorial | Fee 5 Hours Full Course