ORA-02783: Both post and wait functions were not specified
Cause: To ensure that the functions act symmetrically, pointers to both the posting and waiting functions must be given.
Action: Either specify both functions or specify neither. The package will supply its own functions.
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ORA-02783: Both post and wait functions were not specified 错误表明，在调用DBMS_PIPE包中的POST_MESSAGE或WAIT_FOR_MESSAGE函数时，两个函数均未指定。
Cause: Both the post and wait functions were not specified when invoking DBMS_PIPE package.
Action: Specify both the post and wait functions when invoking DBMS_PIPE package.
（1）确认要发送和接收的消息类型；
（2）正确指定函数参数，确保使用正确的参数名称；
（3）正确指定数据长度及字节排列；
（4）确认信息是否发送成功；
（5）确认是否收到期望的消息。