(4. Spring Data JPA) Entity의 기본속성(@Entity)

@Entity

- 해당 객체를 JPA에서 관리하는 객체임을 말함

- PK인 @Id가 반드시 필요

@Id

- 엔티티의 PK

@GeneratedValue

- 어노테이션 안에 GenerationType strategy() default Auto;

- GenerationType이라는 enum 객체안의 TABLE, SEQUENCE, IDENTIY, AUTO

  1. TABLE : DB에 상관없이 ID를 관리하는 별도에 테이블을 사용

  2. SEQUENCE : Oracle, PostgreSql, h2

  3. IDENTITY : MySql, MariaDB

  4. AUTO : 각 DB에 적합한 값을 전달

- 트랜잭션이 종료되기 전, Auto Increase를 통해 아이디 값을 사전에 가져온다. 

@Table 

- 테이블 name, catalog, schema, uniqueConstraints, indexes 설정

- indexes, uniqueConstraints는 일반적으로 사용을 안하고 DB에 직접 설정하는것을 추구(JPA상에서 생성되는 index ID와 제약조건 명이 DDL시 생성)

@NoArgsConstructor
@AllArgsConstructor
@RequiredArgsConstructor
@Data
@Builder
@Entity
@Table(name = "TB_USER", indexes = {@Index(columnList = "name")}, uniqueConstraints = {@UniqueConstraint(columnNames = "email")})
public class User{

Hibernate: 
    
    create table tb_user (
       id bigint not null,
        created_at timestamp,
        email varchar(255),
        name varchar(255),
        updated_at timestamp,
        use_yn boolean,
        primary key (id)
    )
Hibernate: create index IDXjus3xa0l3009mkpbt9i5ilxx3 on tb_user (name)
Hibernate: 
    
    alter table tb_user 
       add constraint UK4vih17mube9j7cqyjlfbcrk4m unique (email)

@Column

- 컬럼에 속성을 지정

- name, nullable, unique, length, insertable, updatable

@NoArgsConstructor
@AllArgsConstructor
@RequiredArgsConstructor
@Data
@Builder
@Entity
@Table(name = "TB_USER", indexes = {@Index(columnList = "name")}, uniqueConstraints = {@UniqueConstraint(columnNames = "email")})
public class User{

    @Id
    @GeneratedValue
    private Long id;

    @NonNull
    private String name;

    @NonNull
    @Column(length = 250)
    private String email;

    @Column(name="reg_at", nullable = false, unique = true)
    private LocalDateTime createdAt;

    private LocalDateTime updatedAt;

//    @OneToMany(fetch = FetchType.EAGER)
//    private List<Address> address;

    private Boolean useYn;
}

Hibernate: 
    
    create table tb_user (
       id bigint not null,
        reg_at timestamp not null,
        email varchar(250),
        name varchar(255),
        updated_at timestamp,
        use_yn boolean,
        primary key (id)
    )
Hibernate: create index IDXjus3xa0l3009mkpbt9i5ilxx3 on tb_user (name)
Hibernate: 
    
    alter table tb_user 
       add constraint UK4vih17mube9j7cqyjlfbcrk4m unique (email)
Hibernate: 
    
    alter table tb_user 
       add constraint UK_tnspm680jp0k2fyjqm19noh9d unique (reg_at)

insertable, updatable

 

@NoArgsConstructor
@AllArgsConstructor
@RequiredArgsConstructor
@Data
@Builder
@Entity
@Table(name = "TB_USER", indexes = {@Index(columnList = "name")}, uniqueConstraints = {@UniqueConstraint(columnNames = "email")})
public class User{

    @Id
    @GeneratedValue
    private Long id;

    @NonNull
    private String name;

    @NonNull
    private String email;

    @Column(updatable = false)
    private LocalDateTime createdAt;

    @Column(insertable = false)
    private LocalDateTime updatedAt;

//    @OneToMany(fetch = FetchType.EAGER)
//    private List<Address> address;

    private Boolean useYn;
}

@Test
void insertableAndUpdatable(){
    User user = new User();
    user.setId(6L);
    user.setName("six");
    user.setEmail("six@gmail.com");
    user.setCreatedAt(LocalDateTime.now());

    userRepository.save(user);

    userRepository.findAll().forEach(System.out::println);
    User user1 = userRepository.findById(6L).orElseThrow(RuntimeException::new);
    user1.setName("seven");
    user1.setUpdatedAt(LocalDateTime.now());
    userRepository.save(user1);
    userRepository.findAll().forEach(System.out::println);
}

Hibernate: 
    select
        user0_.id as id1_1_0_,
        user0_.created_at as created_2_1_0_,
        user0_.email as email3_1_0_,
        user0_.name as name4_1_0_,
        user0_.updated_at as updated_5_1_0_,
        user0_.use_yn as use_yn6_1_0_ 
    from
        tb_user user0_ 
    where
        user0_.id=?
Hibernate: 
    call next value for hibernate_sequence
Hibernate: 
    insert 
    into
        tb_user
        (created_at, email, name, use_yn, id) 
    values
        (?, ?, ?, ?, ?)
Hibernate: 
    select
        user0_.id as id1_1_,
        user0_.created_at as created_2_1_,
        user0_.email as email3_1_,
        user0_.name as name4_1_,
        user0_.updated_at as updated_5_1_,
        user0_.use_yn as use_yn6_1_ 
    from
        tb_user user0_
User(id=1, name=martin, email=martin@fastcampus.com, createdAt=2022-10-16T18:21:42.087515, updatedAt=2022-10-16T18:21:42.087515, useYn=true)
User(id=2, name=dennis, email=dennis@fastcampus.com, createdAt=2022-10-16T18:21:42.089121, updatedAt=2022-10-16T18:21:42.089121, useYn=true)
User(id=3, name=sophia, email=sophia@slowcampus.com, createdAt=2022-10-16T18:21:42.089576, updatedAt=2022-10-16T18:21:42.089576, useYn=true)
User(id=4, name=james, email=james@slowcampus.com, createdAt=2022-10-16T18:21:42.089978, updatedAt=2022-10-16T18:21:42.089978, useYn=true)
User(id=5, name=martin, email=martin@another.com, createdAt=2022-10-16T18:21:42.090394, updatedAt=2022-10-16T18:21:42.090394, useYn=true)
User(id=6, name=six, email=six@gmail.com, createdAt=2022-10-16T18:21:42.295978, updatedAt=null, useYn=null)
Hibernate: 
    select
        user0_.id as id1_1_0_,
        user0_.created_at as created_2_1_0_,
        user0_.email as email3_1_0_,
        user0_.name as name4_1_0_,
        user0_.updated_at as updated_5_1_0_,
        user0_.use_yn as use_yn6_1_0_ 
    from
        tb_user user0_ 
    where
        user0_.id=?
Hibernate: 
    select
        user0_.id as id1_1_0_,
        user0_.created_at as created_2_1_0_,
        user0_.email as email3_1_0_,
        user0_.name as name4_1_0_,
        user0_.updated_at as updated_5_1_0_,
        user0_.use_yn as use_yn6_1_0_ 
    from
        tb_user user0_ 
    where
        user0_.id=?
Hibernate: 
    update
        tb_user 
    set
        email=?,
        name=?,
        updated_at=?,
        use_yn=? 
    where
        id=?
Hibernate: 
    select
        user0_.id as id1_1_,
        user0_.created_at as created_2_1_,
        user0_.email as email3_1_,
        user0_.name as name4_1_,
        user0_.updated_at as updated_5_1_,
        user0_.use_yn as use_yn6_1_ 
    from
        tb_user user0_
User(id=1, name=martin, email=martin@fastcampus.com, createdAt=2022-10-16T18:21:42.087515, updatedAt=2022-10-16T18:21:42.087515, useYn=true)
User(id=2, name=dennis, email=dennis@fastcampus.com, createdAt=2022-10-16T18:21:42.089121, updatedAt=2022-10-16T18:21:42.089121, useYn=true)
User(id=3, name=sophia, email=sophia@slowcampus.com, createdAt=2022-10-16T18:21:42.089576, updatedAt=2022-10-16T18:21:42.089576, useYn=true)
User(id=4, name=james, email=james@slowcampus.com, createdAt=2022-10-16T18:21:42.089978, updatedAt=2022-10-16T18:21:42.089978, useYn=true)
User(id=5, name=martin, email=martin@another.com, createdAt=2022-10-16T18:21:42.090394, updatedAt=2022-10-16T18:21:42.090394, useYn=true)
User(id=6, name=seven, email=six@gmail.com, createdAt=2022-10-16T18:21:42.295978, updatedAt=2022-10-16T18:21:42.463601, useYn=null)

@Transient 

- 객체에서 사용할 속성으로만 지정, 영속성 처리에서 제외 , DB반영 안됨

@Enumerated

- Enum클래스를 사용할 경우. 

- Enum사용시 EnumType.STRING으로 사용하지 않으면 디폴트값이 ORDINAL로 되어 Enum클래스를 사용하면 숫자가 표출

User.java

@Enumerated(value = EnumType.STRING)
private Gender gender;

UserRepository.java

@Query(value = "select * from tb_user limit 1", nativeQuery = true)
Map<String,Object> findRawRecode();

@Test
void enumTest(){
    User user = userRepository.findById(1L).orElseThrow(RuntimeException::new);
    user.setGender(Gender.MALE);
    userRepository.save(user);
    userRepository.findAll().forEach(System.out::println);
    // native query 사용하여 출력시 0 출력. @Enumerated의 속성값인 ORDINARY가 적용
    System.out.println(userRepository.findRawRecode().get("gender"));
}

Hibernate: 
    select
        user0_.id as id1_1_0_,
        user0_.created_at as created_2_1_0_,
        user0_.email as email3_1_0_,
        user0_.gender as gender4_1_0_,
        user0_.name as name5_1_0_,
        user0_.updated_at as updated_6_1_0_,
        user0_.use_yn as use_yn7_1_0_ 
    from
        tb_user user0_ 
    where
        user0_.id=?
Hibernate: 
    select
        user0_.id as id1_1_0_,
        user0_.created_at as created_2_1_0_,
        user0_.email as email3_1_0_,
        user0_.gender as gender4_1_0_,
        user0_.name as name5_1_0_,
        user0_.updated_at as updated_6_1_0_,
        user0_.use_yn as use_yn7_1_0_ 
    from
        tb_user user0_ 
    where
        user0_.id=?
Hibernate: 
    update
        tb_user 
    set
        email=?,
        gender=?,
        name=?,
        updated_at=?,
        use_yn=? 
    where
        id=?
Hibernate: 
    select
        user0_.id as id1_1_,
        user0_.created_at as created_2_1_,
        user0_.email as email3_1_,
        user0_.gender as gender4_1_,
        user0_.name as name5_1_,
        user0_.updated_at as updated_6_1_,
        user0_.use_yn as use_yn7_1_ 
    from
        tb_user user0_
User(id=1, name=martin, email=martin@fastcampus.com, createdAt=2022-10-16T18:43:03.386756, updatedAt=2022-10-16T18:43:03.386756, useYn=true, gender=MALE)
User(id=2, name=dennis, email=dennis@fastcampus.com, createdAt=2022-10-16T18:43:03.389445, updatedAt=2022-10-16T18:43:03.389445, useYn=true, gender=null)
User(id=3, name=sophia, email=sophia@slowcampus.com, createdAt=2022-10-16T18:43:03.390489, updatedAt=2022-10-16T18:43:03.390489, useYn=true, gender=null)
User(id=4, name=james, email=james@slowcampus.com, createdAt=2022-10-16T18:43:03.391428, updatedAt=2022-10-16T18:43:03.391428, useYn=true, gender=null)
User(id=5, name=martin, email=martin@another.com, createdAt=2022-10-16T18:43:03.392437, updatedAt=2022-10-16T18:43:03.392437, useYn=true, gender=null)
Hibernate: 
    select
        * 
    from
        tb_user limit 1
MALE