Wednesday, 3 July 2019

JPA: Primary keys


Every entity must have a primary key. Primary key can be simple or composite.

Simple Primary Key
Simple primary key corresponds to a single persistent fields or property of the class. @Id annotation is used to define a simple primary key.

Composite primary key
It is a combination of more than one persistent field. The EmbeddedId or IdClass annotation is used to denote a composite primary key.




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