EJB. What's the difference between compound primary key and single-field key? Why cannot the primary keys be primitive types in single-field key? I read some books but can't get the answer. thank you!

howru (How are you?)
(#31864@0)
2001-3-9 -05:00

回到话题: EJB. What's the difference between compound primary key and single-field key? Why cannot the primary keys be primitive types in single-field key? I read some books but can't get the answer. thank you!

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