How To Programmatically Create a DSN for SQL Server with VB

This article demonstrates how to programmatically create a Data Source Name (DSN) for SQL Server using Visual Basic. The technique discussed in this article uses Windows Application Programming Interface (API) functions to create and manipulate entries in the Windows Registry.

DSNs are usually created through the ODBC Data Source Administrator window, which is accessible from the Windows Control Panel (or Administrator Tools in Windows 2000). Other techniques that provide access to ODBC-compliant databases include using RegisterDatabase (a Data Access Object (DAO) method), using the SQLConfigDataSource ODBC API function, or using a DSN-less connection string.

However, it is possible to establish a new DSN by manually creating and manipulating values in the Windows Registry. The following technique uses the RegCreateKey, RegSetValueEx, and RegCloseKey API functions to create a system DSN for a SQL Server database.

Step-by-Step Procedures

1. Open a new Visual Basic project. Form1 is created by default. Put a CommandButton on Form1 (Command1), and put the following code in the General Declarations section of the code for Form1:

       Option Explicit
   
       Private Const REG_SZ = 1    'Constant for a string variable type.
       Private Const HKEY_LOCAL_MACHINE = &H80000002
   
       Private Declare Function RegCreateKey Lib "advapi32.dll" Alias _
          "RegCreateKeyA" (ByVal hKey As Long, ByVal lpSubKey As String, _
          phkResult As Long) As Long
   
       Private Declare Function RegSetValueEx Lib "advapi32.dll" Alias _
          "RegSetValueExA" (ByVal hKey As Long, ByVal lpValueName As String, _
          ByVal Reserved As Long, ByVal dwType As Long, lpData As Any, ByVal _
          cbData As Long) As Long
   
       Private Declare Function RegCloseKey Lib "advapi32.dll" _
          (ByVal hKey As Long) As Long
   						

2. Place the following code in the click event of the Command1 button on Form1:
   
   Change the values of the DataSourceName, DatabaseName, Description, DriverPath, LastUser, and Server variables as appropriate for your environment. Any of the drivers listed on the ODBC Drivers tab of the ODBC Data Source Administrator window can be used as part of the DriverPath variable. All of these drivers can be found in C:\Windows\System for Windows 95 or Windows 98 machines and C:\Winnt\System32 for Windows NT.

      Private Sub Command1_Click()
   
      Dim DataSourceName As String
      Dim DatabaseName As String
      Dim Description As String
      Dim DriverPath As String
      Dim DriverName As String
      Dim LastUser As String
      Dim Regional As String
      Dim Server As String
   
      Dim lResult As Long
      Dim hKeyHandle As Long
   
      'Specify the DSN parameters.
   
      DataSourceName = "<the name of your new DSN>"
      DatabaseName = "<name of the database to be accessed by the new DSN>"
      Description = "<a description of the new DSN>"
      DriverPath = "<path to your SQL Server driver>"
      LastUser = "<default user ID of the new DSN>"
      Server = "<name of the server to be accessed by the new DSN>"
      DriverName = "SQL Server"
   
      'Create the new DSN key.
   
      lResult = RegCreateKey(HKEY_LOCAL_MACHINE, "SOFTWARE\ODBC\ODBC.INI\" & _
           DataSourceName, hKeyHandle)
   
      'Set the values of the new DSN key.
   
      lResult = RegSetValueEx(hKeyHandle, "Database", 0&, REG_SZ, _
         ByVal DatabaseName, Len(DatabaseName))
      lResult = RegSetValueEx(hKeyHandle, "Description", 0&, REG_SZ, _
         ByVal Description, Len(Description))
      lResult = RegSetValueEx(hKeyHandle, "Driver", 0&, REG_SZ, _
         ByVal DriverPath, Len(DriverPath))
      lResult = RegSetValueEx(hKeyHandle, "LastUser", 0&, REG_SZ, _
         ByVal LastUser, Len(LastUser))
      lResult = RegSetValueEx(hKeyHandle, "Server", 0&, REG_SZ, _
         ByVal Server, Len(Server))
   
      'Close the new DSN key.
   
      lResult = RegCloseKey(hKeyHandle)
   
      'Open ODBC Data Sources key to list the new DSN in the ODBC Manager.
      'Specify the new value.
      'Close the key.
   
      lResult = RegCreateKey(HKEY_LOCAL_MACHINE, _
         "SOFTWARE\ODBC\ODBC.INI\ODBC Data Sources", hKeyHandle)
      lResult = RegSetValueEx(hKeyHandle, DataSourceName, 0&, REG_SZ, _
         ByVal DriverName, Len(DriverName))
      lResult = RegCloseKey(hKeyHandle)
   
      End Sub
   						

3. Run the project and click on the Command1 command button. Then open up the ODBC Data Source Administrator from the Control Panel (or Administrator Tools in Windows 2000). Your new DSN will appear along with the other system DSNs that you have already created.

For additional information, please see the following articles in the Microsoft Knowledge Base: