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Delete Record from MS Access using MFC

Posted on 2008-06-19
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613 Views
Last Modified: 2013-11-20
Hi all,

I downloaded this project: http://www.codeproject.com/KB/database/readdb.aspx

and I can't seem to delete a record from this DB.

When i call Open on the recordset i get this exception:

"Dynamic cursors not supported by ODBC driver."

Help anyone?
// I added this function to the project:
 

void CReadDBDlg::OnDelete() 

{

		// TODO: Add your control notification handler code here

	CDatabase database;

	CString SqlString;

	CString sCatID, sCategory;

	CString sDriver = "MICROSOFT ACCESS DRIVER (*.mdb)";

	CString sDsn;

	CString sFile = "d:\\works\\ReadDB\\Test.mdb";

	// You must change above path if it's different

	int iRec = 0; 	

	

	// Build ODBC connection string

	sDsn.Format("ODBC;DRIVER={%s};DSN='';DBQ=%s",sDriver,sFile);
 

	// Open the database

	if(!database.Open(NULL,false,false,sDsn))

		return;
 

	CRecordset rsStudentSet(&database);
 

	TRY

	{

		

	// remove student from all the classes

    // the student is enrolled in
 

		if ( !database.BeginTrans( ) )

			return;
 

		

		CString SqlString =  "SELECT CatID, Category "

				"FROM Categories WHERE CatID = 22";
 

		if ( !rsStudentSet.Open(CRecordset::dynamic    , SqlString  , CRecordset::none) )

			return;
 

        while ( !rsStudentSet.IsEOF( ) )

        {

			CString sCatID,sCategory;
 

			rsStudentSet.GetFieldValue("CatID",sCatID);

			rsStudentSet.GetFieldValue("Category",sCategory);
 
 

			AfxMessageBox(sCatID + " - " + sCategory);
 

			if(rsStudentSet.CanUpdate())

			{

				rsStudentSet.Delete( );

				rsStudentSet.MoveNext( );

			}

        }
 

        database.CommitTrans( );

    }
 

    CATCH_ALL(e)

    {

        database.Rollback( );

        return;

    }

    END_CATCH_ALL
 

    rsStudentSet.Close( );
 

    return;
 

}

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Question by:kozmo_jonny
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12 Comments
 
LVL 49

Expert Comment

by:Gustav Brock
Comment Utility
Well, did you try with Static?

But why ODBC with dotNet? Because that code is dated 2001?

Create a DataTableAdapter using the native driver for OLE db and a DataTable, then all the plumbing for CRUD (create, read, update, delete) is created automatically.

/gustav
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LVL 44

Expert Comment

by:AndyAinscow
Comment Utility
CRecordset::dynamic
Isn't that telling it to use a dynamic cursor?  (See the error message).

Change that to another value (static cursor) and see if it works.



ps. There are a complete classes in MFC (CDaoRecordset...) specifically for using access databases in MFC.
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Author Comment

by:kozmo_jonny
Comment Utility
i tried it with all open options. none work.
0
 
LVL 49

Expert Comment

by:Gustav Brock
Comment Utility
Are you running Visual Studio?

A bunch of examples and learning videos for reading/updating an Access table exist. None of these, I believe, use ODBC.

/gustav
0
 
LVL 2

Author Comment

by:kozmo_jonny
Comment Utility
in my questions you can see my whole project.

http://www.codeproject.com/KB/database/readdb.aspx

i'm using VS6
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LVL 44

Expert Comment

by:AndyAinscow
Comment Utility
>>i tried it with all open options. none work.

Do you get other error messages?
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LVL 49

Expert Comment

by:Gustav Brock
Comment Utility
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Author Comment

by:kozmo_jonny
Comment Utility
I tried them all :-) none work my friend.

Option: rsStudentSet.Open(CRecordset::dynamic
Exception: {"Dynamic cursors not supported by ODBC driver."}

Option: rsStudentSet.Open(CRecordset::dynaset
Exception: {"ODBC driver does not support dynasets."}

Option: rsStudentSet.Open(CRecordset::snapshot
Exception: {"No columns were bound prior to calling SQLFetchScroll/SQLExtendedFetch"}

help me :'(
0
 
LVL 44

Expert Comment

by:AndyAinscow
Comment Utility
?
As I said earlier - any reason you don't want to use the MFC classes specifically for access databases?
0
 
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Author Comment

by:kozmo_jonny
Comment Utility
no reason, it's the only sample project i found that uses MFC & MSACCESS.

I have a project in MFC (VS6) that I need to add MS ACCESS capabilities. so i started this as a small test case for me.

If you have another example that works i would love to see it.

10x
0
 
LVL 49

Expert Comment

by:Gustav Brock
Comment Utility
I haven't worked with MFC but I noticed these samples - in C++ but might be helpful anyway:

http://msdn.microsoft.com/en-us/library/aa728901(VS.71).aspx

/gustav
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Accepted Solution

by:
AndyAinscow earned 500 total points
Comment Utility
Look up CDaoDatabase, CDaoRecordset and other classes that begin with CDao in the help files.  There should be code snippets there.

There is at least one sample application and code that comes with VS6 that deals specifically with these classes.  (MFC and samples in the help file).
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