Checking for an SQL result in VB.NET

Question

I need to check if my SQL statement returned any results from the Access db I\'m using to store my data.

I have this code atm:

        cn = New OleDbConn         


        

Answer 1

The simple answer, I guess, is this:

    Dim hasResults as Boolean = false
    cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=D:\Computing Project\database.mdb;")
    cn.Open()
    cmd = New OleDbCommand("SELECT * FROM(" & roomvar.ToLower() & ") WHERE (((" & roomvar.ToLower() & ".date)=" & Chr(34) & dtpDate.Value.Date & Chr(34) & "))", cn)
    dr = cmd.ExecuteReader
        While dr.Read()
             hasResults = true
        End While
    End If
    dr.Close()

My vb-syntax is a little rusty, but you get the idea.
But I'm not sure that this is what you actually want.

Another variant could be

Dim hasResults as Boolean = false
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=D:\Computing Project\database.mdb;")
cn.Open()
cmd = New OleDbCommand("SELECT 1 FROM(" & roomvar.ToLower() & ") WHERE (((" & roomvar.ToLower() & ".date)=" & Chr(34) & dtpDate.Value.Date & Chr(34) & "))", cn)
dr = cmd.ExecuteReader
    If dr.Read() Then
         hasResults = true
    End If
End If
dr.Close()