ODBC DSN-less connection

This is a discussion on ODBC DSN-less connection within the Windows Programming forums, part of the Platform Specific Boards category; I am trying to connect directly to my visual FoxPro database without using a datasource. With a datasource it worked ...

  1. #1
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    ODBC DSN-less connection

    I am trying to connect directly to my visual FoxPro database without using a datasource.
    With a datasource it worked fine, but I can not get it to work without one. Can someone check my connection code line here:
    Code:
    SQLDriverConnect(hdbc, NULL, (unsigned char*)"Driver={Microsoft FoxPro VBF Driver}; SourceType=DBF; SourceDB=data/CATADA.DBF; Exclusive=No \0", SQL_NTS, NULL, 0, NULL, 0);
    or give me exact code to connect to a database without a datasource. I went to a number of MSDN pages but none of them helped me figure it out.

    thanks a lot,
    esaptonor

  2. #2
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    What error return are you getting?
    What does GetLastError() return?

    I just get my apps to create their own DSN at runtime.



    Is your path correct?
    Shouldn't it be, for a DB file 'CATADA.dbf' in the subfolder 'data' off the working folder;

    Code:
    SQLDriverConnect(hdbc, NULL, (unsigned char*)"Driver={Microsoft FoxPro VBF Driver}; SourceType=DBF; SourceDB=.\\data\\CATADA.DBF; Exclusive=No \0", SQL_NTS, NULL, 0, NULL, 0);
    SDIT:
    I suggest printing the 'InConnectionString' to a string / char to ensure that it contains what you think it does....
    Last edited by novacain; 05-22-2007 at 11:51 PM.
    "Man alone suffers so excruciatingly in the world that he was compelled to invent laughter."
    Friedrich Nietzsche

    "I spent a lot of my money on booze, birds and fast cars......the rest I squandered."
    George Best

    "If you are going through hell....keep going."
    Winston Churchill

  3. #3
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    hmm...well for starters I found it was a .dbc not .dbf :|
    But that didn't solve the problem. I continued to search around and try different things, but I just can not seem to get it working.

    Can you explain how your application created its own DSN at runtime? that sounds like a good alternative.

    thanks,
    esaptonor

  4. #4
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    something like

    Code:
    iRet=SQLConfigDataSource(NULL,ODBC_ADD_SYS_DSN, (LPSTR) "SQL Server",
    						 (LPSTR)"DSN=TestingMyDSN\0"
    						 "Server=192.168.0.1\0"
    						 "Database=MY_DB_NAME\0"
    						 "Trusted_Connection=NO\0"
    						 "Description=This is the DSN for my app\0");
    if(!iRet)
    {
              //error check
              iRet=GetLastError();
    
    //remove DSN when finished?
    SQLConfigDataSource(NULL,ODBC_REMOVE_SYS_DSN,NULL,(LPSTR)"TestingMyDSN");
    You will have to change the parameters to meet your DB settings and type (ie not SQLServer, file DSN ect).
    I assume you know where to check the DSN settings under Administrative Tools.
    I assume you know that some corp machines will have security to block these changes to the registry.

    EDIT:
    Each section of the string must be null terminated and so the end of the string will be double null terminated.
    I have a loop that adds the params to a string as the user will change/supply the DSN settings in the app during runtime.
    Code:
    char		szAttrib[1028]={'\0'};
    char		*pAttrib=NULL,*pParam=NULL;
    
    _snprintf(szDSN,127,"DSN=%s",szSuppliedDSN);
    _snprintf(szServer,127,"Server=%s",szSuppliedServer);
    _snprintf(szDatabase,127,"Database=%s",szSuppliedDatabase);
    _snprintf(szConnection,127,"Trusted_Connection=NO");
    _snprintf(szDescription,127,"This is the DSN For %s",szAppName);
    pAttrib=szAttrib;
    for(i=0;i<5;i++)
    {
    	switch(i)
    	{
    		case 0:
    			pParam=szDSN;
    			iLen=lstrlen(szDSN);
    		break;
    		case 1:
    			pParam=szServer;
    			iLen=lstrlen(szServer);
    		break;
    		case 2:
    			pParam=szDatabase;
    			iLen=lstrlen(szDatabase);
    		break;
    		case 3:
    			pParam=szConnection;
    			iLen=lstrlen(szConnection);
    		break;
    		case 4:
    			pParam=szDescription;
    			iLen=lstrlen(szDescription);
    		break;
    	}
    	//null terminate
    	pParam[iLen]='\0';
    	//add to the attrib string
    	strcpy(pAttrib,pParam);
    	pAttrib+=iLen+1;
    }
    Last edited by novacain; 06-07-2007 at 07:35 PM. Reason: Wrong params
    "Man alone suffers so excruciatingly in the world that he was compelled to invent laughter."
    Friedrich Nietzsche

    "I spent a lot of my money on booze, birds and fast cars......the rest I squandered."
    George Best

    "If you are going through hell....keep going."
    Winston Churchill

  5. #5
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    thanks, I will look into this

  6. #6
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    hmm...its returning error 11. No idea what that is, I shall investigate further.

    Its worth noting that your code works fine, its just this visual fox pro thing that doesn't work.
    Last edited by esaptonor; 06-08-2007 at 03:08 AM.

  7. #7
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    Its something to do with the database location... When I just have
    Code:
    rc=SQLConfigDataSource(hwnd,ODBC_ADD_DSN,(LPSTR)"Microsoft FoxPro VFP Driver (*.dbf)",
    						 (LPSTR)"DSN=cadatatest\0\0");
    it opens a dialog box asking for the additional information, but if I use
    Code:
    rc=SQLConfigDataSource(hwnd,ODBC_ADD_DSN,(LPSTR)"Microsoft FoxPro VFP Driver (*.dbf)",
    					(LPSTR)"DSN=cadatatest\0Database=C:\\data\\CADATA.DBC\0\0");
    it just fails and returns error code 11, which corresponds to ODBC_ERROR_REQUEST_FAILED.


    EDIT: The problem was I had to write DB= instead of Database =
    Last edited by esaptonor; 06-08-2007 at 04:28 PM.

  8. #8
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    Quote Originally Posted by esaptonor View Post
    EDIT: The problem was I had to write DB= instead of Database =

    Hmmmmm......MS being inconsistent?

    I checked my code again and for Access and SQL Server I use 'Database'.

    Glad you got it to work (you did get it to work?)
    "Man alone suffers so excruciatingly in the world that he was compelled to invent laughter."
    Friedrich Nietzsche

    "I spent a lot of my money on booze, birds and fast cars......the rest I squandered."
    George Best

    "If you are going through hell....keep going."
    Winston Churchill

  9. #9
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    yes it all works great now, thanks a lot!

    For the record, Visual Foxpro databases require DNS=, SourceType=, Description=, and DB= in that string. That was half the problem right there!

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