JPA Date Time

• Spring Data JPA & Joda-Time
  • MySQL에 millisecond 단위가 없는데, 데이터를 넣을 때 ms를 넣으면 무조건 올림이 돼버리는 현상 발생.
  • Date 필드의 길이를 6으로 지정해서 애초에 잘라버리면 될 듯(columnDefinition = “datetime(6)”).
• Jodatime 설정 2. JPA Configuration

  <property name="jadira.usertype.autoRegisterUserTypes" value="true" /> 1
  <property name="jadira.usertype.databaseZone" value="jvm" />

• http://jadira.sourceforge.net/

• Hibernate @ValueGenerationType 을 이용하여 자동으로 생성/수정시간 생성
• How to persist creation and update timestamps with Hibernate
• Hibernate의 @CreationTimestamp, @UpdateTimestamp를 사용하는 것이 좋겠다.
• [HHH-11096] @CreationTimestamp doesn't works with @Column(nullable=false) - Hibernate JIRA nullable=false일때 오류 발생하는 버그 있음. 5.4에서 해결된 듯.

@Column
@CreationTimestamp
private LocalDateTime createDateTime;
 
@Column
@UpdateTimestamp
private LocalDateTime updateDateTime;

• MySQL에서 DEFAULT 값 사용시

@Generated(GenerationTime.INSERT) 
@Column
private LocalDateTime createDateTime;
 
@Generated(GenerationTime.ALWAYS)  
@Column
private LocalDateTime updateDateTime;

created_at      DATETIME(6)  NOT NULL DEFAULT CURRENT_TIMESTAMP(6),
modified_at     DATETIME(6)  NOT NULL DEFAULT CURRENT_TIMESTAMP(6) ON UPDATE CURRENT_TIMESTAMP(6),

• 해당 필드에 insertable=false, updatable=false 설정을 해준다.
• Hibernate @Generated 로 필드를 지정해야한다.
• JPA + Hibernate - Refreshing an Entity Instance

• How to persist LocalDate and LocalDateTime with JPA
• ThreeTen JPA converter
• https://bitbucket.org/montanajava/jpaattributeconverters
• Jadira Java 8 DateTime/JodaTime Hibernate usertype

• How to map the Java YearMonth type with JPA and Hibernate
• How to map java.time.Year and java.time.Month with JPA and Hibernate
• Hibernate Tips: How to Map java.time.Year with JPA and Hibernate
• YearMonth, Year, Month 는 AttributeConverter 만들어야 함.

• Hibernate – Mapping Date and Time | Baeldung
• How to store date, time, and timestamps in UTC time zone with JDBC and Hibernate - Vlad Mihalcea