java:hibernate:valuegenerationtype

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--- java:hibernate:valuegenerationtype [2021/10/07 21:57]
kwon37xi 만듦
+++ java:hibernate:valuegenerationtype [2021/10/07 22:02]
kwon37xi
@@ 줄 4: / 줄 4: @@
   * [[https://docs.jboss.org/hibernate/orm/6.0/javadocs/org/hibernate/tuple/AnnotationValueGeneration.html|AnnotationValueGeneration]] 를 구현하여 실제로 값을 생성해주고, 이렇게 생성된 값이 필드의 값으로 자동으로 들어간다.
   * 이를 기반으로 하여 [[https://docs.jboss.org/hibernate/orm/6.0/javadocs/org/hibernate/tuple/CreationTimestampGeneration.html|CreationTimestampGeneration]] [[https://docs.jboss.org/hibernate/orm/6.0/javadocs/org/hibernate/tuple/UpdateTimestampGeneration.html|UpdateTimestampGeneration]] 등이 만들어졌다.
+  * see [[java:hibernate:generated|Hibernate @Generated]]
+===== Example =====
+<code java>
+@Entity(name = "Event")
+public static class Event {
+	@Id
+	@GeneratedValue
+	private Long id;
+	@Column(name = "`timestamp`")
+	@FunctionCreationTimestamp
+	private Date timestamp;
+	//Constructors, getters, and setters are omitted for brevity
+}
+@ValueGenerationType(generatedBy = FunctionCreationValueGeneration.class)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface FunctionCreationTimestamp {}
+public static class FunctionCreationValueGeneration
+		implements AnnotationValueGeneration<FunctionCreationTimestamp> {
+	@Override
+	public void initialize(FunctionCreationTimestamp annotation, Class<?> propertyType) {
+	}
+	/**
+	 * Generate value on INSERT
+	 * @return when to generate the value
+	 */
+	public GenerationTiming getGenerationTiming() {
+		return GenerationTiming.INSERT;
+	}
+	/**
+	 * Returns null because the value is generated by the database.
+	 * @return null
+	 */
+	public ValueGenerator<?> getValueGenerator() {
+		return null;
+	}
+	/**
+	 * Returns true because the value is generated by the database.
+	 * @return true
+	 */
+	public boolean referenceColumnInSql() {
+		return true;
+	}
+	/**
+	 * Returns the database-generated value
+	 * @return database-generated value
+	 */
+	public String getDatabaseGeneratedReferencedColumnValue() {
+		return "current_timestamp";
+	}
+}
+</code>

java/hibernate/valuegenerationtype.txt · 마지막으로 수정됨: 2021/10/07 22:04 저자 kwon37xi