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 tutorial, we will learn how to write a LessThan query method or finder method using Spring Data JPA.
Example: Let's write the Spring Data JPA query method to find or retrieve products whose price is less than the given price as a method parameter.
Maven Dependencies
Create a Spring boot project and add the following maven dependencies to it:
<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>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
Product Entity
Let's first create a Product entity class and add the following content to it:
package com.springdatajpa.springboot.entity;
import lombok.*;
import org.hibernate.annotations.CreationTimestamp;
import org.hibernate.annotations.UpdateTimestamp;
import javax.persistence.*;
import java.math.BigDecimal;
import java.time.LocalDateTime;
@Entity
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@ToString
@Table(
name = "products",
schema = "ecommerce",
uniqueConstraints = {
@UniqueConstraint(
name = "sku_unique",
columnNames = "stock_keeping_unit"
)
}
)
public class Product {
@Id
@GeneratedValue(
strategy = GenerationType.IDENTITY
)
private Long id;
@Column(name = "stock_keeping_unit", nullable = false)
private String sku;
@Column(nullable = false)
private String name;
private String description;
private BigDecimal price;
private boolean active;
private String imageUrl;
@CreationTimestamp
private LocalDateTime dateCreated;
@UpdateTimestamp
private LocalDateTime lastUpdated;
}
ProductRepository
Let's create ProductRepository which extends JpaRepository and add the following code to it:
package com.springdatajpa.springboot.repository;
import com.springdatajpa.springboot.entity.Product;
import org.springframework.data.jpa.repository.JpaRepository;
import java.math.BigDecimal;
public interface ProductRepository extends JpaRepository<Product, Long> {
/**
* Return the products whose price is less than given price as method parameter
* @param price
* @return
*/
List<Product> findByPriceLessThan(BigDecimal price);
}
List<Product> findByPriceLessThan(BigDecimal price);
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/ecommerce?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 ecommerce database before running the Spring boot application. Also, change the MySQL username and password as per your MySQL installation on your machine.
Testing Spring Data JPA - LessThan Query Method
Let's write the JUnit test to test Spring Data JPA - LessThan Query Method:
package com.springdatajpa.springboot.repository;
import com.springdatajpa.springboot.entity.Product;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import java.math.BigDecimal;
@SpringBootTest
public class QueryMethodsTest {
@Autowired
private ProductRepository productRepository;
@Test
void findByPriceLessThanMethod(){
List<Product> products = productRepository.findByPriceLessThan(new BigDecimal(200));
products.forEach((p) -> {
System.out.println(p.getId());
System.out.println(p.getName());
});
}
}
Here is the output of the above JUnit test:
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