SELECT * FROM OpenQuery(
ADSI,
'SELECT displayName, title, department, employeeID, userAccountControl
FROM ''LDAP://dc=testdomain''
WHERE objectCategory = ''Person'' AND
      objectClass = ''user'' AND
      userAccountControl=512')

Msg 7321, Level 16, State 2, Line 1
An error occured while preparing the query "SELECT displayName, title, department, employeeID, userAccountControl
            FROM 'LDAP://dc=testdomain'
            WHERE objectCategory = 'Person' AND
                  objectClass = 'user' AND
            userAccountControl=512" for execution against OLE DB provider "ADsDSOObject" for linked server "ADSI".

SQL Server 11.0.5058
Linked Server: ADSI
Provider: OLE DB Provider for Microsoft Directory Services
Product name: Active Directory Services 2.5
Data source: adsdatasource
Provider string: ADsDSOObject

Be made using the login's current security context

Ole DB Provider  Options:
Allow in process

Failed to retreive data for this request. (Microsoft.SqlServer.Management.Sdk.Sfc)

Additional information:
    An exception occured while executing a Transact-SQL statement or batch.
    (Microsoft.SqlServer.ConnectionInfo)
        Cannot obtain the required interface ("IID_IDBSchemaRowset") from OLE DB provider "ADsDSOObject"
        for linked server "ADSI". (Microsoft SQL Server, Error: 7301)

'References: Microsoft ActiveX Data Objects 2.8 Library
Public Sub testADSI()
    On Error Resume Next

    Dim cn As ADODB.Connection
    Dim cmd As ADODB.Command
    Dim rs as ADODB.Recordset
    Dim MySql as String
    Dim n as Integer

    Set cn = New ADODB.Connection
    Set cmd = New ADODB.Command
    Set rs = New ADODB.Recordset

    cn.Provider = "ADsDSOObject"
    cn.Open "Active Directory Provider"

    Set cmd.ActiveConnection = cn

    cmd.Properties("Page Size")= 1000

    MySql = "SELECT displayName, title, department, employeedID, userAccountControl " & _
            "FROM 'LDAP://dc=testdomain' " _ &
            "WHERE objectCategory = 'Person' AND " & _
                  "objectClass = 'user' AND " & _
                  "userAccountControl=512"

    rs.Open MySql, cn, 1

    If rs.RecordCount > 0 Then
        MsgBox "Sucess! " & rs.RecordCount & " records found!"
    Else
        MsgBox "No records"
    End IF
End Sub