Next up in Listing 2 is the @IdClass annotation, which defines the composite key class reference.

清单2中的下一个注释是 @IdClass，它定义组合键类引用。

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You can also create a primary key class for entities that have composite keys.

还可以为具有组合键的实体创建一个主键类。

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You can also create a primary key class for entities that have composite keys.

还可以为具有组合键的实体创建一个主键类。

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