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The SQL query generated by ClassWizard should have formed the JOIN clause automatically. In case it didn't, you'll need to do it manually. For example, here is a JOIN on three tables of a database I recently worked on:
SELECT [Meet].[Name], [Meet].[Date], [Gymnast].[Name], [Scores].[Score1]
FROM Meet INNER JOIN (Gymnast INNER JOIN Scores ON [Gymnast].[AutoNumber]=[Scores].[GymnastNum]) ON [Meet].[AutoNumber]=[Scores].[MeetNum]
ORDER BY meet.date; Search MSDN for different examples of LEFT, RIGHT, INNER, FULL, CROSS, and OUTER joins.
"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen
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HI ,
I want to write a program, which Continuesly read from COM port.
but i want to do , as data Come on COM port it reads it , and use accoedingly.
I not want to that it reads in Continuse loop . and remain busy .
i want as in Socket as data recives event fires then we recive it and use it.
is there any event that is fired when data
is come( written) on COM port.
thanx
Regards.
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Yes and no. The COM ports, by default, are continous IO. They don't fire events unless you specify so, and tell them what events they fire. This is called asynchronous communication, or overlapped IO, and is fairly well covered by many articles in the Net.
Here[^] is a link to one, right here on Code Project.
-Antti Keskinen
----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.
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I am working with VC++ 6.0 with Windows-DDK installed in the system and correct Directory-path (Include & Library) set. After compilation of any VC++ project from workspace when I start the build-process, I am getting a linker-warning as follows.
[LINK : warning LNK4078: multiple ".rdata" sections found with different attributes (C0000040)]
My project-setting involves "Incremental-Linking" and I am using Debug-build. This is not a project-specific warning. Any simple MFC application is throwing this LNK-warning during build.
If anyone has come across this situation, please let me know how to get rid of this problem...
Koushik Chakrabarti
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if this warning doesn't cause any problems with the software then you can easily ignore it.
Don't try it, just do it! 
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I'm having two istream-related problems. Please can somebody help... 
Problem 1
void loadStuffFromStream (istream& stream)
{
stream.seekg( length, ios_base::cur );
}
***edited*** This seems to skip to an arbitrary position in the stream, instead of 'current position' + length bytes. Why does it do this?
Problem 2
char ch;
int pos;
...
pos = stream.tellg();
stream.get (ch);
pos = stream.tellg();
stream.get (ch);
pos = stream.tellg();
stream.get (ch);
pos = stream.tellg();
stream.get (ch);
Not so much a 'problem' as a matter of curiosity. Why is there a sudden leap in the read-position reported by tellg the first time I read from the stream? (N.B. It is reading the correct characters into ch!)
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I want to know something about video chat.for example:whici protocal is preferred,which Interface is used to record video data and audio data.
I also want to know whether the data structure used to store the video data and audio data is the same.if not,the procedure of recording video and audio is separately executed.IGraphicBuilder and ICaptureGraphBuilder2 are used to capture video. and Recording audio data is execute by another interfaces?
please help me,thanks a lot
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you question is very very general. what about fetching some information before asking?
there are articles about video capturing on cp!
Don't try it, just do it!
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Could you give me some advices? such as book,URL etc. Thanks a lot
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Hi,
how can i use the Console in vc++ .net?
I've seen an example code at MSDN like:
Console::WriteLine("blabla");
However, I need to reference the "System" namespace i guess...It's easy to do that in VB.NET and C# but how to do that in VC++.NET ?
Thanks
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There's one crucial difference.
VC++ .NET is standard C++, you can write console applications by creating a file that contains the function main and links with the C Runtime Library.
However, Managed Extensions for C++ (MC++) is the C++ version you use to write software for .NET Framework. MC++ is the language that can be compared with C# or VB .NET, for example. VC++ .NET is not a .NET language.
In MC++, you need to use the import statements to use the .NET Framework. For example:
#import <mscorlib.dll>
#import <system.dll>
System::Console::Writeline( L"BlaBla" ); Microsoft is currently developing the C++/CLI specification, which is MUCH more flexible and usable than MC++. To write programs with this language, you need to have the Visual C++ Express 8 Beta version, available from Microsoft as a free download.
-Antti Keskinen
----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.
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Thanks a lot 
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hi,
How can we use the thumbnail view in a list ctrl?
bye
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Hello I am only a beginner. I like to ask if how to use visual c++? What are their variables?
Dark Angel
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What do you mean with variables??
Hardy.
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What to use in visual c++? I mean their language and code.
Dark Angel
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Language -- for what?? Programming language - c++, Language for user interface ?? Whatever you like.
Are you a programmer?
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Are you familiar with C or C++ programming?? Do you have any programming experience. If not, then I suggest you to learn C++ language first, before moving to Visual C++.
ARSALAN MALIK
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Hi !
I'm calling a function of a api to which I have to give a pointer to a callback function. Here is the typedef :
typedef int (*proc_restore_progress_callback)(restore_progress_data*)
The problem is that I want, as the callback method, to pass a method of my own class. I tried something like this :
api_set_restore_progress_callback(JSPartLoader::setRestoreProgress);*)
Here is the signature of the 'setRestoreProgress' method :
int JSPartLoader::setRestoreProgress(restore_progress_data* pProgressData);*)
But I get a compiler error :
error C2664: 'set_restore_progress_callback' : impossible to convert the parameter 1 from 'int (restore_progress_data *)' to 'proc_restore_progress_callback'
Is it possible to give a class' method as the callback function or do I have to have a global function which will be the callback function ?
Thanks for your help !
Jerome
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This problem is related to the class abstracty concept. As you specify that ClassA::MethodA is a callback function for some other function, then how, at run-time, can then code determine the correct instance of class ?
The problem is most often faced in wrapping Win32 API functions inside C++ classes. GameDev.Net has an excellent article about this, here[^].
If you wish to use a class method as callback's target, the method must be declared static, or you need to have a static router function that can flawlessly determine the instance to which the method should be routed.
Also, there is a Code Project article written by Nitzan Shaked here[^] that provides yet another approach to the problem.
Hope this helps..
-Antti Keskinen
----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.
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Many thanks for your help Antti ! I'll have a look at the different methods you suggest !
Thanks,
Jerome
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Is there anybody who worked on memory leaks in MFC,
whenever a model dialog is open there is an increase of 4 k bytes of memory and when it is closed it is not released.
And also whenever a spin control is used for the first time there is an increase of memory which is not reduced when the dialog is closed.
Why it is like this? where is the leak?
vidya
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