Spring Boot - JPA를 이용한 CRUD

UserRepositoryTest.java

package com.example.study.repository;

import com.example.study.StudyApplicationTests;
import com.example.study.model.entity.User;
import org.junit.Assert;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

import javax.transaction.Transactional;
import java.time.LocalDateTime;
import java.util.Optional;

public class UserRepositoryTest extends StudyApplicationTests {

    // Dependency Injection (DI)
    @Autowired
    private UserRepository userRepository;

    @Test
    public void create(){
        // String sql = insert into user (%s, %s, %d) value (account, email, age);
        User user = new User();
        user.setAccount("TestUser03");
        user.setEmail("TestUser03@gmail.com");
        user.setPhoneNumber("010-3333-3333");
        user.setCreatedAt(LocalDateTime.now());
        user.setCreatedBy("TestUser3");

        User newUser = userRepository.save(user);
        System.out.println("newUser : " + newUser);
    }


    @Test
    public void read(){
        Optional<User> user = userRepository.findById(2L);

        user.ifPresent(selectUser ->{
            System.out.println("user : " + selectUser);
            System.out.println("email : " + selectUser.getEmail());
        });
    }

    @Test
    public void update(){
        Optional<User> user = userRepository.findById(2L);

        user.ifPresent(selectUser ->{
            selectUser.setAccount("PPPP");
            selectUser.setUpdatedAt(LocalDateTime.now());
            selectUser.setUpdatedBy("update method()");

            userRepository.save(selectUser);
        });
    }

    @Test
    @Transactional  // 실제로 DB에서 삭제되지 않게함, 단지 Test 이기 때문
    public void delete(){
        Optional<User> user = userRepository.findById(2L);

        Assert.assertTrue(user.isPresent());    // 반드시 위의 값이 존재해야함, true

        user.ifPresent(selectUser->{
            userRepository.delete(selectUser);
        });

        Optional<User> deleteUser = userRepository.findById(2L);

        if(deleteUser.isPresent()){
            System.out.println("데이터 존재 : " + deleteUser.get());
        }else{
            System.out.println("데이터 삭제 되었음");
        }

        Assert.assertFalse(deleteUser.isPresent()); // 위의 값이 존재하면 안됨, false
    }
}