NT Login and User Table Validation

[graviz]

I have a table call "User_Auth" with two fields (Name & NT_Login). I have some code where it checks to see what a users nt login is and stores it in a variable.

Code For User Name Checking:

Private Declare Function apiGetUserName Lib "advapi32.dll" Alias _
"GetUserNameA" (ByVal lpBuffer As String, nSize As Long) As Long
Function fOSUserName() As String
' Returns the network login name
Dim lngLen As Long, lngX As Long
Dim strUserName As String
strUserName = String$(254, 0)
lngLen = 255
lngX = apiGetUserName(strUserName, lngLen)
If (lngX > 0) Then
fOSUserName = Left$(strUserName, lngLen - 1)
Else
fOSUserName = vbNullString
End If
End Function

I've always hard coded it as to which users I want to give access to (i.e. If fOSUserName = "john.smith" Then" something) . I have a project I'm working on where I would like it to loop through that table and see if it matches one of the users. I know it's probably basic but could someone please assist me with some code to get this to work?

User Name Stored in "fOSUserName"
Table Name: User_Auth
NT Field Name: NT_Login

Thanks!

 

[Addyman]

If you just want to check it exists in the table you don't need to loop through it can't you just use a DLookup?

Unless I've not understood what you need to do.

 

[graviz]

If you just want to check it exists in the table you don't need to loop through it can't you just use a DLookup?

Unless I've not understood what you need to do.

So how would you write it?

Dim UN_Check as String

UN_Check = DLookup("[NT_Login]", "User_Auth", fOSUserName")

I know the last part of a dlookup is the criteria so how would I write it? I haven't used a dlookup before.

 

[Addyman]

If IsNull(DLookup("[NT_Login]", "User_Auth", "[NT_Login] = '" & fOSUserName & "'")) Then

'Code here if it doesn't exist

Else

'Code here if it does

End If

 

[graviz]

If IsNull(DLookup("[NT_Login]", "User_Auth", "[NT_Login] = '" & fOSUserName & "'")) Then

'Code here if it doesn't exist

Else

'Code here if it does

End If

Thanks! I knew I was making it more complex than it needs to be.