AssociationOverride (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 AssociationOverride

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

This annotation is used to override a many-to-one or one-to-one mapping of property or field for an entity relationship.

The AssociationOverride annotation may be applied to an entity that extends a mapped superclass to override a many-to-one or one-to-one mapping defined by the mapped superclass. If the AssociationOverride annotation is not specified, the join column is mapped the same as in the original mapping.

    Example:
    @MappedSuperclass
    public class Employee {
        ...
        @ManyToOne
        protected Address address;
        ...
    }
    
    @Entity 
    @AssociationOverride(name="address", 
        joinColumns=@JoinColumn(name="ADDR_ID"))
    // address field mapping overridden to ADDR_ID fk
    public class PartTimeEmployee extends Employee {
        ...
    }

从以下版本开始:: Java Persistence 1.0
另请参见:: OneToOne, ManyToOne, MappedSuperclass

Required Element Summary
`JoinColumn[]`	`joinColumns` The join column that is being mapped to the persistent attribute.
`String`	`name` The name of the relationship property whose mapping is being overridden if property-based access is being used, or the name of the relationship field if field-based access is used.

元素详细信息

name

public abstract String name

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

joinColumns

public abstract JoinColumn[] joinColumns

The join column that is being mapped to the persistent attribute. The mapping type will remain the same as is defined in the mapped superclass.

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