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@Target({METHOD,FIELD}) @Retention(RUNTIME) public @interface MapKey
Specifies the map key for associations of typeMap
when the map key is itself the primary key or a persistent field or property of the entity that is the value of the map.If a persistent field or property other than the primary key is used as a map key then it is expected to have a uniqueness constraint associated with it.
The
MapKeyClass
annotation is not used whenMapKey
is specified and vice versa.Example 1: {@snippet :
- Since:
- 1.0
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Optional Element Summary
Optional Elements Modifier and Type Optional Element Description java.lang.String
name
(Optional) The name of the persistent field or property of the associated entity that is used as the map key.
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Element Detail
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name
java.lang.String name
(Optional) The name of the persistent field or property of the associated entity that is used as the map key.Default: If the
name
element is not specified, the primary key of the associated entity is used as the map key. If the primary key is a composite primary key and is mapped asIdClass
, an instance of the primary key class is used as the key.- Default:
- ""
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