How can I list the DSNs configured on a computer using VBA?

Question

I have an Excel application in which I want to present the user with a list of data source names (e.g. DSN) through which he / she can choose which data source to use.

Hopefully when I get a list, I can easily access the DSN properties to connect to the corresponding database.

Please note: I do not want to use a connection without a DSN.

Answer 1

DSN entries are stored in the registry in the following keys.

HKEY_CURRENT_USER \ Software \ ODBC \ ODBC.INI \ ODBC Data Sources
HKEY_LOCAL_MACHINE \ SOFTWARE \ ODBC \ ODBC.INI \ ODBC Data Sources

DSN. , DSN DSN :

HKEY_CURRENT_USER\Software\ODBC\ODBC.INI
HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI

User DSN System DSN (ODBC) , .

DSN, > a > (ODBC) [ User Dsn].

http://support.microsoft.com/kb/178755

  Option Explicit

  Private Declare Function RegOpenKeyEx Lib "advapi32.dll" _
      Alias "RegOpenKeyExA" _
      (ByVal hKey As Long, _
      ByVal lpSubKey As String, _
      ByVal ulOptions As Long, _
      ByVal samDesired As Long, phkResult As Long) As Long

  Private Declare Function RegEnumValue Lib "advapi32.dll" _
      Alias "RegEnumValueA" _
      (ByVal hKey As Long, _
      ByVal dwIndex As Long, _
      ByVal lpValueName As String, _
      lpcbValueName As Long, _
      ByVal lpReserved As Long, _
      lpType As Long, _
      lpData As Any, _
      lpcbData As Long) As Long

  Private Declare Function RegCloseKey Lib "advapi32.dll" _
      (ByVal hKey As Long) As Long

  Const HKEY_CLASSES_ROOT = &H80000000
  Const HKEY_CURRENT_USER = &H80000001
  Const HKEY_LOCAL_MACHINE = &H80000002
  Const HKEY_USERS = &H80000003

  Const ERROR_SUCCESS = 0&

  Const SYNCHRONIZE = &H100000
  Const STANDARD_RIGHTS_READ = &H20000
  Const STANDARD_RIGHTS_WRITE = &H20000
  Const STANDARD_RIGHTS_EXECUTE = &H20000
  Const STANDARD_RIGHTS_REQUIRED = &HF0000
  Const STANDARD_RIGHTS_ALL = &H1F0000
  Const KEY_QUERY_VALUE = &H1
  Const KEY_SET_VALUE = &H2
  Const KEY_CREATE_SUB_KEY = &H4
  Const KEY_ENUMERATE_SUB_KEYS = &H8
  Const KEY_NOTIFY = &H10
  Const KEY_CREATE_LINK = &H20
  Const KEY_READ = ((STANDARD_RIGHTS_READ Or _
                    KEY_QUERY_VALUE Or _
                    KEY_ENUMERATE_SUB_KEYS Or _
                    KEY_NOTIFY) And _
                    (Not SYNCHRONIZE))

  Const REG_DWORD = 4
  Const REG_BINARY = 3
  Const REG_SZ = 1

  Private Sub Command1_Click()
     Dim lngKeyHandle As Long
     Dim lngResult As Long
     Dim lngCurIdx As Long
     Dim strValue As String
     Dim lngValueLen As Long
     Dim lngData As Long
     Dim lngDataLen As Long
     Dim strResult As String

     lngResult = RegOpenKeyEx(HKEY_CURRENT_USER, _
             "SOFTWARE\ODBC\ODBC.INI\ODBC Data Sources", _
              0&, _
              KEY_READ, _
              lngKeyHandle)

     If lngResult <> ERROR_SUCCESS Then
         MsgBox "Cannot open key"
         Exit Sub
     End If

     lngCurIdx = 0
     Do
        lngValueLen = 2000
        strValue = String(lngValueLen, 0)
        lngDataLen = 2000

        lngResult = RegEnumValue(lngKeyHandle, _
                                 lngCurIdx, _
                                 ByVal strValue, _
                                 lngValueLen, _
                                 0&, _
                                 REG_DWORD, _
                                 ByVal lngData, _
                                 lngDataLen)
        lngCurIdx = lngCurIdx + 1

        If lngResult = ERROR_SUCCESS Then
           strResult = strResult & lngCurIdx & ": " & Left(strValue, lngValueLen) & vbCrLf
        End If
     Loop While lngResult = ERROR_SUCCESS
     Call RegCloseKey(lngKeyHandle)

     Call MsgBox(strResult, vbInformation)
  End Sub

Answer 2

SQLDataSources API ODBC. . MSDN.

Answer 3

. , CURRENT_USER DSN, , , . LOCAL_MACHINE DSN, , , CURRENT_USER.

http://msdn.microsoft.com/en-us/library/windows/desktop/ms712603(v=vs.85).aspx