AttributeOverride (Java EE 5 SDK)

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Java EE 5 SDK

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摘要: REQUIRED | OPTIONAL

详细信息: ELEMENT

javax.persistence Annotation Type AttributeOverride

@Target(value={TYPE,METHOD,FIELD}) @Retention(value=RUNTIME) public @interface AttributeOverride

The AttributeOverride annotation is used to override the mapping of a Basic (whether explicit or default) property or field or Id property or field.

The AttributeOverride annotation may be applied to an entity that extends a mapped superclass or to an embedded field or property to override a basic mapping defined by the mapped superclass or embeddable class. If the AttributeOverride annotation is not specified, the column is mapped the same as in the original mapping.

  Example:

   @MappedSuperclass
   public class Employee {
       @Id protected Integer id;
       @Version protected Integer version;
       protected String address;
       public Integer getId() { ... }
       public void setId(Integer id) { ... }
       public String getAddress() { ... }
       public void setAddress(String address) { ... }
   }

   @Entity
   @AttributeOverride(name="address", column=@Column(name="ADDR"))
   public class PartTimeEmployee extends Employee {
       // address field mapping overridden to ADDR
       protected Float wage();
       public Float getHourlyWage() { ... }
       public void setHourlyWage(Float wage) { ... }
   }

从以下版本开始:: Java Persistence 1.0
另请参见:: Embedded, Embeddable, MappedSuperclass

Required Element Summary
`Column`	`column` (Required) The column that is being mapped to the persistent attribute.
`String`	`name` (Required) The name of the property whose mapping is being overridden if property-based access is being used, or the name of the field if field-based access is used.

元素详细信息

name

public abstract String name

(Required) The name of the property whose mapping is being overridden if property-based access is being used, or the name of the field if field-based access is used.

column

public abstract Column column

(Required) The column that is being mapped to the persistent attribute. The mapping type will remain the same as is defined in the embeddable class or mapped superclass.

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