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源自:6-2 关于红包收发之操作数据库(下)

为什么直接插入,不适用optional会造成有null的情况呢?

为什么直接插入,不适用optional会造成有null的情况呢?

提问者:慕粉4088762 2020-02-20 21:56

个回答

  • stop110
    2020-02-21 16:25:47


    Saves a given entity. Use the returned instance for further operations as the save operation might have changed theentity instance completely.

    Type Parameters:<S> Parameters:entity must not be null.Returns:the saved entity; will never be null.