Search for DataSourceName

[Kirk]

Hi:

I would like to check for a DSN in the registry. I've searched through the relevant articles and posts here but I still don't get how to do it.

I've tried using RegQueryValue which seems to be close to what I want. I snagged the following to try to retrieve the name of the database. What I'd really like to do is find out if the datasource is there.

Dim hKey As Long ' receives a handle to the newly created or opened registry key
Dim subkey As String ' name of the subkey to open
Dim stringbuffer As String ' receives data read from the registry
Dim datatype As Long ' receives data type of read value
Dim slength As Long ' receives length of returned data
Dim retval As Long ' return value

' Set the name of the new key and the default security settings
subkey = "Software\ODBC\ODBC.INI"

' Create or open the registry key
retval = RegOpenKeyEx(HKEY_LOCAL_MACHINE, subkey, 0, KEY_READ, hKey)
If retval <> 0 Then
Debug.Print "ERROR: Unable to open registry key!"
Exit Sub
End If

' Make room in the buffer to receive the incoming data.
stringbuffer = Space(255)
slength = 255
' Read the "username" value from the registry key.
retval = RegQueryValueEx(hKey, "DataSourceName", 0, datatype, ByVal stringbuffer, slength)
' Only attempt to display the data if it is in fact a string.
If datatype = REG_SZ Then
' Remove empty space from the buffer and display the result.
stringbuffer = Left(stringbuffer, slength)
Debug.Print "Database: "; stringbuffer
Else
' Don't bother trying to read any other data types.
Debug.Print "Data not in string format. Unable to interpret data."
End If

' Close the registry key.
retval = RegCloseKey(hKey)

End Sub

(Snagged from http://209.207.250.135/ref/r/regqueryvalueex.html)

[Stevie]

Try this ...

Private Function DSNExist(DSNName As String) As Boolean
'***************************************************************************
'Purpose:     Determines whether a DSN already exists.
'Parameters:  DSNName - DSN Name to be checked for.
'Returns:     True/False - DSN Exists.
'***************************************************************************
Dim lngKeyHandle As Long
Dim lngReturn As Long
Dim strKey As String
  
  DSNExist = False
  
  strKey = "SOFTWARE\ODBC\ODBC.INI\" & DSNName
  
  ' Open registry key
  lngReturn = RegOpenKeyEx(HKEY_CURRENT_USER, strKey, 0, KEY_READ, lngKeyHandle)
  
  If lngReturn = ERROR_SUCCESS Then
    
    DSNExist = True
    
    ' Close registry key
    RegCloseKey lngKeyHandle
  
  End If

End Function

Put this in a code module ...

Public 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

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

' RegOpenKey and RegCloseKey consts
Public Const HKEY_CURRENT_USER = &H80000001
Public Const ERROR_SUCCESS = 0&
Public Const KEY_QUERY_VALUE = &H1
Public Const KEY_NOTIFY = &H10
Public Const READ_CONTROL = &H20000
Public Const KEY_ENUMERATE_SUB_KEYS = &H8
Public Const STANDARD_RIGHTS_READ = (READ_CONTROL)
Public Const SYNCHRONIZE = &H100000
Public Const KEY_READ = ((STANDARD_RIGHTS_READ Or KEY_QUERY_VALUE Or KEY_ENUMERATE_SUB_KEYS Or KEY_NOTIFY) And (Not SYNCHRONIZE))

Hope this helps

[Edited by Stevie on 09-27-2000 at 09:01 AM]

[Kirk]

Looks simple - I will give it a try!