问题描述
我创建了一个在包装中返回NUMBER类型的函数，但未在包装规格"中声明此函数.
I have created a function which return NUMBER type in a package, but not declare this function in the Package Specification.
我在同一个程序包主体中的另一个函数的SQL查询中调用此函数.我收到错误消息.
I am calling this function in SQL query in anther function with in same package body. I am getting error.
当我在包装规格"中声明功能时，则其&工作.
When i declare function in Package Specification Then its fine & working.
我想知道背后的原因.请任何人解释.
I want to know reason behind it. Please anybody explain it.
推荐答案
与正向声明完全无关.
这涉及到您使用SQL查询来调用函数的事实.似乎在使用语句调用函数时，您不再位于PL/SQL包的范围之内，因此只能调用公共可用的函数.
This deals with the fact that you are using a SQL query to call the function. It seems like when using a statement to invoke a function, you are no longer inside the scope of the PL/SQL package, thus you can only call publicly available functions.
关于原因，我只能猜测，因此请不要以为然，但是 PL/SQL和SQL具有不同的引擎.因此，在执行sql查询时，即使在您的pl/sql程序包中，您也进入SQL级别，它将根据SQL引擎再次检查权限.因此完全不知道它是从PL/SQL包中执行的，应该允许您调用私有函数.
As for the why, I can only guess, so don't take it as granted, but PL/SQL and SQL have different engines. So, when doing a sql query, even inside your pl/sql package, you go to the level of SQL where it'll check again the permissions according to the SQL engine. So it has no idea it is executed from within a PL/SQL package and you should be allowed to call the private function.
我认为可以轻松检查引擎之间的差异，请尝试使用32000的varchar2，它将在您的pl/sql函数中正常工作.现在，如果调用pl/sql函数返回varchar2(32000)，它将失败.这是我遇到的一个问题，但是我没有数据库可以给您摘要.
I think the difference of engines can be checked easily, try to use a varchar2 of 32000, it'll work within your pl/sql function. Now, if you call your pl/sql function returning a varchar2(32000), it'll fail. Thi is a problem I ran into, but I don't have any databse to give you a snippet.
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