How to add a data source (ODBC)

You can add a data source by using ODBC Administrator, programmatically (by using SQLConfigDataSource), or by creating a file.

To add a data source by using ODBC Administrator

On the Start menu, point to Settings, and then click Control Panel.
Double-click ODBC.
Click the User DSN, System DSN, or File DSN tab, and then click Add.
Click SQL Server; then click Finish.
Complete the steps in the Create a New Data Source to SQL Server Wizard.

To add a data source programmatically

Call SQLConfigDataSource with the fOption set to either ODBC_ADD_DSN or ODBC_ADD_SYS_DSN.

To add a file data source

Call SQLDriverConnect with a SAVEFILE=file_name parameter in the connect string. If the connect is successful, the ODBC driver creates a file data source with the connection parameters in the location pointed to by the SAVEFILE parameter.

Examples

A. Create a data source using SQLConfigDataSource

#include <stdio.h>

#include <windows.h>

#include "sql.h"

#include <odbcinst.h>

int main()

{

RETCODE retcode;

UCHAR *szDriver = "SQL Server";

UCHAR *szAttributes =

"DSN=MyDSN\0DESCRIPTION=SQLConfigDSN Sample\0"

"SERVER=MySQL\0ADDRESS=MyServer\0NETWORK=dbmssocn\0"

"DATABASE=pubs\0";

retcode = SQLConfigDataSource(NULL,

ODBC_ADD_DSN,

szDriver,

szAttributes);

B. Create a file data source

Use the SAVEFILE keyword in SQLDriverConnect to create a file data source, and then use SQLDriverConnect to connect with the file data source. This example has been simplified by removing error handling.

#include <stdio.h>

#include <string.h>

#include <windows.h>

#include <sql.h>

#include <sqlext.h>

#include <odbcss.h>

#define MAXBUFLEN 255

SQLHENV henv = SQL_NULL_HENV;

SQLHDBC hdbc1 = SQL_NULL_HDBC;

int main() {

RETCODE retcode;

// This format of the SAVEFILE keyword saves a successful

// connection as the file Myfiledsn.dsn in the ODBC default

// directory for file DSNs.

SQLCHAR szConnStrIn[MAXBUFLEN] =

"SAVEFILE=MyFileDSN;DRIVER={SQL Server};SERVER=MySQL;"

"NETWORK=dbmssocn;UID=sa;PWD=MyPassWord;";

SQLCHAR szConnStrOut[MAXBUFLEN];

SQLSMALLINT cbConnStrOut = 0;

// Allocate the ODBC Environment and save handle.

retcode = SQLAllocHandle (SQL_HANDLE_ENV, NULL, &henv);

// Let ODBC know this is an ODBC 3.0 application.

retcode = SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION,

(SQLPOINTER) SQL_OV_ODBC3, SQL_IS_INTEGER);

// Allocate an ODBC connection handle and connect.

retcode = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc1);

retcode = SQLDriverConnect(hdbc1, // Connection handle

NULL, // Window handle

szConnStrIn, // Input connect string

SQL_NTS, // Null-terminated string

szConnStrOut, // Addr of output buffer

MAXBUFLEN, // Size of output buffer

&cbConnStrOut, // Address of output length

SQL_DRIVER_NOPROMPT);

// Disconnect, set up a new connect string, and then test file DSN.

SQLDisconnect(hdbc1);

strcpy(szConnStrIn, "FILEDSN=MyFileDSN;UID=sa;PWD=MyPassWord;");

retcode = SQLDriverConnect(hdbc1, // Connection handle

NULL, // Window handle

szConnStrIn, // Input connect string

SQL_NTS, // Null-terminated string

szConnStrOut, // Addr of output buffer

MAXBUFLEN, // Size of output buffer

&cbConnStrOut, // Address of output length

SQL_DRIVER_NOPROMPT);

/* Clean up. */

SQLDisconnect(hdbc1);

SQLFreeHandle(SQL_HANDLE_DBC, hdbc1);

SQLFreeHandle(SQL_HANDLE_ENV, henv);

return(0);

}