DSN Creation through SQLConfigDataSource() funciton

[Durga_Devi]

Hi, The following sample failed to create the DSN, void main() { //As my DB path will change frequently i am using this method. bool aDSNCreated = false; char temp[MAX_PATH]; sprintf(temp,"DSN=SAMPLE\0DBQ=D:\\SAMPLE.mdb\0"); aDSNCreated = SQLConfigDataSource(NULL, ODBC_ADD_SYS_DSN, "Microsoft Access Driver (*.mdb)\0", temp); printf("%d",aDSNCreated ); } whereas when I execute the below code; it execute successfully.Can anyone help in this why its happening? void main() { bool aDSNCreated = false; aDSNCreated = SQLConfigDataSource(NULL, ODBC_ADD_SYS_DSN, "Microsoft Access Driver(*.mdb)\0","DSN=SAMPLE\0DBQ=D:\\SAMPLE.mdb\0"); printf("%d",aDSNCreated ); }

[Moak]

DurgaDevi_hr wrote:

"Microsoft Access Driver(*.mdb)\0","DSN=SAMPLE\0DBQ=D:\\SAMPLE.mdb\0"

Interesting string format with a double Null-Terminator[^], what were they thinking? The extra Null-Terminator will cause problems with most C-Runtime string functions. Have a look at SQLConfigDataSource attributes with variables[^], does this help? /M

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[Durga_Devi]

Hi Moak, I tried the logic as specified in the link. It worked fine. Thanks for that. But can u tell me, why SQLConfigDataSource() parameter alone is accepting the null terminator string? Any idea about that? :)

[Moak]

DurgaDevi_hr wrote:

But can u tell me, why SQLConfigDataSource() parameter alone is accepting the null terminator string?

In a nutshell, the SQLConfigDataSource() uses a strange string format and with a literal text string this is fortunately not a problem (your second example code). But when you use string functions such as sprintf/strcpy/strlen they will stop at the first Null-Terminator. For example "bla\0fasel\0" would be copied only to the the first \0 and becomes "bla\0". You can try it in the debugger. :)

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modified on Monday, December 14, 2009 7:53 AM

[Durga_Devi]

Tanx for ur reply!!

[David Crow]

DurgaDevi_hr wrote:

The following sample failed to create the DSN,

So then why aren't you calling SQLInstallerError() to find out why?

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