How do i Open a recordset returned from DLL

[FaisalHenry]

I am trying to implement a 3 tier architecture here,
a DLL named DataServices, have a class PassengerData, with a method GetPassengersData that have a Recordset Return type.

The code is listed below:
Public Function getpassengersdata() As ADODB.Recordset
Dim rs As New ADODB.Recordset
Dim cn As New ADODB.Connection

cn.ConnectionString= "Provider=Microsoft.Jet.OLEDB.3.51;" & _
"DataSource=c:\1cruiseline\database\dbcruise.mdb"
cn.Open
rs.Open "qryPassenger", cn
rs.MoveFirst
Set getpassengerdata = rs
End Function

I tried to access the DLL with this code:
Private Sub Command1_Click()
Dim objPassenger As Object
Dim rs As New ADODB.Recordset

Set objPassenger = CreateObject("dataservices.passengerdata&quot
Set rs = objPassenger.getpassengersdata
rs.MoveFirst
End Sub

at the rs.MoveFirst code i got a run time error 3704, it says that the operation is not allowed if the object is closed

But if i use the rs.Open command, i need a valid connection,
this is not the kind of behavior that i want.

Any suggestion on how to open the RecordSet ?

 

[Mats]

Hi,

I bit of a different approach (don't know if it will help you...)

In the calling sub or function:

Dim rst as recordset
set rst=new recordset
Call YourFunction(byref rst as recordset)

In 'YourFunction' ->open the recordset passed to the function. The recordset is accessible to the calling sub straight away since it's only passed byref.

Mats

 

[RobertP]

I first set the CursorLocation property:

rs.CursorLocation = adUseClient

and then when opening the recordset in DLL I use:

rs.Open strSQL, cnn, adOpenStatic, adLockReadOnly, adCmdText

i.e. with 3 extra options set to you.

Remember that when you copy the DLLs recordset to a local one, it inherits the properties, but loses the connection. Thus, as the default recordset behaviour is Dynamic, it is obviously struggling when it suddenly finds itself without a connection. By setting the recordset to Static you should solve the problem, and no longer need to open the connection at the client side.

Rob.