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Hello,
So does that mean that a layer of Serialization is necessary for reading or writing to databases at the server.There is no direct method to access server databases.
Thanks for your reply WalderMort
Prithaa
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prithaa wrote: can I write a program using CSocket classes to support the database interaction?
how do you except CSocket to support the database interaction.
with CSocket you can send a buffer. U can use Send() and Receive() function for sending and receiving data. CArchive is not a must.
nave
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Hello,
I have use CRecordSet class to read and write to a database on a single PC.Now if I want to access a database on a server which topics or classes I will have to go through.I just read about CSocket so I thought it will help me in database read/write as well.
Thanks for your reply.
Prithaa
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in the server, u can read the data from the database. Put the read data in some structure and then pass this structure through the socket to the client.
Similarly u can right data from client to server also.
nave
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Hello,
Yes, I understood what you said.But how do I read data from the database and put in the structure. For doing this which topics should I cover.
Thanks nave
Prithaa
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prithaa wrote: I have use CRecordSet class to read and write to a database on a single PC
If you have done that then, depending on the database server you are using, you can adjust your
CDatabase connection settings to access a database server on a network. Then the communication
is done for you.
Otherwise you need to do all your database access in your server app, and handle the transfer of
data (possibly using sockets) to/from the client(s).
Two possible methods.
Mark
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Hello,
thanks
So, I should go through CSocket class for client/server support for database access?
or CDatabase will work for the connections purpose once proper Host String or IP address is given .
I don't know what an IP address means but if that is the address of the server which has to be given at the client side.
Prithaa
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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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