QueryLookupStrategy CREATE IF NOT FOUND

QueryLookupStrategy#CREATE IF NOT FOUND it is the default QueryLookupStrategy of Spring Data JPA. it combines the CREATE and USE DECLARED QUERY. It first tries to find a declared query, if found then will use it else will parse the method name, resolve the parameters and create an underlying database query from it.

CREATE IF NOT FOUND is the default query lookup strategy hence declaring or has the same effect. @EnableJpaRepositories is equivalent to @EnableJpaRepositories(queryLookupStrategy = USE_DECLARED_QUERY)

in the below example, Query is not defined, so Spring Data JPA will try to parse and resolve the method name.

drop database if exists AppleDb;
create database AppleDb;
use AppleDb;
CREATE TABLE apple ( apple_id BIGINT NOT NULL, apple_name VARCHAR(255) DEFAULT NULL, PRIMARY KEY (apple_id)) ENGINE=INNODB;
CREATE TABLE hibernate_sequence ( next_val BIGINT) ENGINE=INNODB;

insert into hibernate_sequence values ( 6 );
insert into apple (apple_id, apple_name ) values (1, "Macintosh");
insert into apple (apple_id, apple_name ) values (2, "Fuji");
insert into apple (apple_id, apple_name ) values (3, "Gala");
insert into apple (apple_id, apple_name ) values (4, "Jonagold");
insert into apple (apple_id, apple_name ) values (5, "GrannySmith");

package com.sujan.example.jpa.controller;

import com.sujan.example.jpa.entity.Apple;
import com.sujan.example.jpa.repository.AppleRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class AppleController {
    @Autowired
    private AppleRepository appleRepository;

    @GetMapping
    List<Apple> findByAppleName() {
        List<Apple> findByAppleName = appleRepository.findByAppleName("Macintosh");
        System.out.println("findByAppleName = " + findByAppleName);
        return findByAppleName;
    }
}

package com.sujan.example.jpa.entity;

import lombok.Data;
import lombok.NoArgsConstructor;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Data
@Entity
@NoArgsConstructor
public class Apple {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long appleId;
    private String appleName;
}

package com.sujan.example.jpa.repository;

import com.sujan.example.jpa.entity.Apple;
import org.springframework.data.jpa.repository.JpaRepository;

import java.util.List;

public interface AppleRepository extends JpaRepository<Apple, Long> {
    List<Apple> findByAppleName(String appleName);
}

package com.sujan.example.jpa;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

import static org.springframework.data.repository.query.QueryLookupStrategy.Key.CREATE_IF_NOT_FOUND;

@SpringBootApplication
@EnableJpaRepositories(queryLookupStrategy = CREATE_IF_NOT_FOUND)
public class JpaApplication {
    public static void main(String[] args) {
        SpringApplication.run(JpaApplication.class, args);
    }
}

spring.datasource.url=jdbc:mysql://localhost:3306/AppleDb
spring.datasource.username=root
spring.datasource.password=root

plugins {
    id 'org.springframework.boot' version '2.3.3.RELEASE'
    id 'io.spring.dependency-management' version '1.0.10.RELEASE'
    id 'java'
}
group = 'com.sujan'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '11'
configurations {
    compileOnly {
        extendsFrom annotationProcessor
    }
}
repositories {
    mavenCentral()
}
dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    annotationProcessor 'org.projectlombok:lombok'
    compileOnly 'org.projectlombok:lombok'
    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
    runtimeOnly 'mysql:mysql-connector-java'
    testImplementation('org.springframework.boot:spring-boot-starter-test') {
        exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
    }
}
test {
    useJUnitPlatform()
}

curl --location --request GET 'http://localhost:8080/'

select apple0_.apple_id as apple_id1_0_, apple0_.apple_name as apple_na2_0_ from apple apple0_ where apple0_.apple_name=?
findByAppleName = [Apple(appleId=1, appleName=Macintosh)]