C ++编译器不了解db_command属性 [英] C++ Compiler Doesn't Understand the db_command Attribute

问题描述

Hi all;
I am working my way through the documentation for a walkthrough (C++):
"Walkthrough: Creating a Rich Client Application with MFC"
ms-help://MS.VSCC.v90/MS.MSDNQTR.v90.en/dv_vswalk/html/ff258cfd-ccf1-4986-815e-e586809b9f51.htm

At one point, the walkthrough specifies that I should copy-paste
a code snippet into the OnInitialUpdate method of the CMyProjectView class.
The snippet implements the db_command attribute:
============================================================
<pre>   HRESULT hr = S_OK;
   TCHAR szAuthor[80];
   CMyProjectSet &dbset = GetDocument()->m_MyProjectSet;
   [db_command(name="cmd", source_name="dbset", hresult=hr)
   {
      SELECT au_lname
      ([bindto]szAuthor)
      FROM AUTHORS
   }];
   while(cmd.MoveNext() == S_OK)
      m_DataList.InsertString(-1, szAuthor);

================================================== ==========

在构建时，编译器不知道这些东西是什么，并且
做出相应的反应-具有几个编译诊断:
================================================== ==========
错误

============================================================

On build, the compiler has no idea as to what that stuff is, and
reacts accordingly - with several compilation diagnostics:
============================================================
Error

1   error C2143: syntax error : missing ']' before '{'  c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 99  Authors-02
Error   2   error C2440: 'initializing' : cannot convert from 'HRESULT' to 'const char *'   c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 98  Authors-02
Error   3   error C2143: syntax error : missing ';' before '{'  c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 99  Authors-02
Error   4   error C2065: 'SELECT' : undeclared identifier   c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 101 Authors-02
Error   5   error C2146: syntax error : missing ';' before identifier 'au_lname'    c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 101 Authors-02
Error   6   error C2143: syntax error : missing ')' before '['  c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 101 Authors-02
Error   7   error C2065: 'bindto' : undeclared identifier   c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 101 Authors-02
Error   8   error C2146: syntax error : missing ';' before identifier 'szAuthor'    c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 101 Authors-02
Error   9   error C3861: 'au_lname': identifier not found   c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 101 Authors-02
Error   10  error C2059: syntax error : ')' c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 101 Authors-02
Error   11  error C2146: syntax error : missing ';' before identifier 'FROM'    c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 102 Authors-02
Error   12  error C2065: 'FROM' : undeclared identifier c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 103 Authors-02
Error   13  error C2146: syntax error : missing ';' before identifier 'AUTHORS' c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 103 Authors-02
Error   14  error C2065: 'AUTHORS' : undeclared identifier  c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 103 Authors-02
Error   15  error C2143: syntax error : missing ';' before '}'  c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 103 Authors-02
Error   16  error C2143: syntax error : missing ';' before ']'  c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 103 Authors-02
Error   17  error C2065: 'cmd' : undeclared identifier  c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 105 Authors-02
Error   18  error C2228: left of '.MoveNext' must have class/struct/union   c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 105 Authors-02
Error   19  fatal error C1903: unable to recover from previous error(s); stopping compilation   c:\projects\aaaplayground\walkthroughs\authors-02\authors-02\authors-02view.cpp 105 Authors-02

================================================== ==========
如何让编译器识别该属性?
我在这里想念什么?
我正在使用Visual Studio2008.
谢谢!!!

============================================================
How do I get the compiler to recognise the attribute?
What am I missing here?
I''m using Visual Studio 2008.
Thanks!!!

推荐答案

好像我的答案丢失了.我认为您需要[和db_command之间的空间.您还可以在MSDN上下载示例，然后尝试查看它们是否有效以及它们与您的代码有何不同.

Looks like my answer was lost. I think you need a space between [ and db_command. You could also download the samples on MSDN and try to see if they work, and how they differ from your code.

我已经得到了答案:文档中的代码不是好.
在线文档更加准确.

感谢您的阅读！！！

I''ve gotten the answer: The code within the docs is no good.
The online docs are more accurate.

Thanks for reading!!!

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