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I think it depends on the system you are developing, how it will be used, how scaleable you want
it, what the database system provides, how many concurrent users, etc.
Some advantages of writing your own server between the clients and the database server are:
Direct control over security - can provide encryption for plain-text over the network
Direct control over database connections - For example, connection pooling can be implemented to
reduce the number of server seat/connection licenses required.
I would suggest searching for articles and studying the difference between 2-tier database
connectivity (client-database) and 3-tier connectivity (client-server-database). Here's one
example: Multi Tier Architectures for Database Connectivity[^]
If you choose to do your own client-server communication then definitely study sockets -
especially if don't know what an IP address means. Sockets know nothing about the data you
are transferring. Sockets just provide the endpoints for the connection. You'll need to
come up with a scheme for transferring data that both ends understand.
Windows Sockets 2[^]
Mark
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Hi All,
please suggest me how to avoid memory leak ADO.
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voorugonda prashanth wrote: please suggest me how to avoid memory leak ADO.
Free the memory you've allocated?
"It's supposed to be hard, otherwise anybody could do it!" - selfquote
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If I voted messages, I'd give you a five. Of course, I'd also like to add that he should consider other employment opportunities after that kind of question...
"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997 ----- "...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001
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John Simmons / outlaw programmer wrote: Of course, I'd also like to add that he should consider other employment opportunities after that kind of question...
"It's supposed to be hard, otherwise anybody could do it!" - selfquote
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I have created a Visual Studio.NET 2003 project using MFC. It's a gaming project. If I execute this project a window opens. After completing all the gaming operations,if I close the window, an exception occurs stating that
'Unhandled exception at 0x7c918fea in Perspective.exe: 0xC0000005: Access violation writing location 0x00000010.'
This exception occurs under both Debug and Release modes.
When I break this exception, it goes to a class free.c which is not created by me.
How to resolve this exception?
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As error says, its due to access violation. And that is due to your code.
Can you post relevent code ?
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Follow the call stack until you find a function that you wrote. And there you will find the cause of the problem.
Alcohol. The cause of, and the solution to, all of life's problems - Homer Simpson
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When you get a crash when accessing location 0 or something near 0, it means you're dereferencing a null pointer.
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I think your problem is of pointers.
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T.RATHA KRISHNAN wrote: Unhandled exception at 0x7c918fea in Perspective.exe: 0xC0000005: Access violation writing location 0x00000010.'
you tried to called something on NULL pointer without providing it memory
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and you
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Hello,
How do I assign a value to an object of type CDBVariant?Especially if the data type is string.
CDBVariant b;
CString str;
b.m_dwtype = DBVT_STRING;
b.m_pstring = str;
but in the union of CDBVariant m_pstring is pointer to string.so what has to be done?
Thanks
Pritha
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prithaa wrote: b.m_pstring = str
Pass address of string.
CDBVariant b;
CString str;
b.m_dwtype = DBVT_STRING;
b.m_pstring = &str;
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Hello,
So I need to maintain the CString variable so that the pointer has a meaning .I cannot destroy the the CString object or create the object locally ? i.e
Thanks for your reply Prasad
Prithaa
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prithaa wrote: b.m_pstring = str;
instead use
b.m_pstring = new CString(str);
the destructor of the CDBVariant will delete this newly created CString.
nave
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Hi,
I am developing a application in which i need to convert the .DWG/.BMP image files into PNG image file format. Can anybody help me to this in VC++ ?
Thanks in Advance !!
Jiteen
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See http://www.wotsit.org[^] for info about graphic files.If you want to save file you can read bmp or png(not dwg)file with CImage class and use of CImage::Save but for dwg I think you need to lot of work.;)
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Thanks a lot sir !!
Jiteen
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You're welcome
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how to add checkboxs for multiple coloumns in listview..
LVS_EX_CHECKBOXES is working for only one coloumn.......
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pavan_sw wrote: how to add checkboxs for multiple coloumns in listview..
LVS_EX_CHECKBOXES is working for only one coloumn...
CLIstCtrl::ModifyStyleEx
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and you
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How to make ON_ENCHANGE message Map returning an int or CSize?
I have added this in the header file:
afx_msg int OnEnChangeEditmessage();
The message map I added was :
ON_EN_CHANGE(IDC_EDITMESSAGE, _OnEnChangeEditmessage)
My message handling function is:
int CPreferences::OnEnChangeEditmessage()
{
CPaintDC *pDC;
CSize size;
size = pDC->GetTextExtent(m_strMessage);
return size.cx;
}
ikikhjkhjkhjkhj
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Typecast OnEnChangeEditmessage in ON_EN_CHANGE(IDC_EDITMESSAGE, OnEnChangeEditmessage) to the original prototype.
Come online at:-
jubinc@skype
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