Return DataTable from a Function - asp.net

Question

I have a Function which returns DataTable Like this (if there are Rows)...
Protected Function getAideData() As DataTable
Dim dt As DataTable = DAL.ReturnData("select * from pg_PersonalInfo P Left Join pg_employeeInterview E on E.sesID = P.sesID ")
If dt.Rows.Count > 0 Then
Return dt
End If
End Function
Then later in my page I accress it like this:
Dim d as datatable = getAideData
Here is my problem: If I have Data in Datatable then I have no problem, however if I dont have any data returned from my method then there is a issue.
I guess my question is, if I have a Function and that cannot return a datatable (no rows), then what should I return from my function? So i can handle the data properly later in my application.

Answer 1

I guess my question is, if I have a Function and that cannot return a
datatable (no rows), then what should I return from my function?
Return Nothing
Protected Function getAideData() As DataTable
Dim dt As DataTable = DAL.ReturnData("select * from pg_PersonalInfo P Left Join pg_employeeInterview E on E.sesID = P.sesID ")
If dt.Rows.Count > 0 Then
Return dt
End If
Return Nothing
End Function

Answer 2

Function GetDataTable(ByVal qry As String) As DataTable
Dim DbCon As New OleDb.OleDbConnection
Try
Dim ConStr As String
ConStr = System.Configuration.ConfigurationManager.AppSettings("ConnCMSTrend").ToString()
DbCon.ConnectionString = ConStr
DbCon.Open()
Dim queryString As String = qry
Dim adapter As OleDbDataAdapter = New OleDbDataAdapter(queryString, ConStr)
Dim res As DataSet = New DataSet
adapter.Fill(res)
DbCon.Close()
GetCMSTrend = res.Tables(0)
Catch ex As Exception
DbCon.Close()
End Try
End Function
'Note That you need to add the connection string in the appsettings file. In the above case ConnCMSTrend is the database connection string.