Count guest reservation visual studio Ms access - vb.net

Question

I've been trying this for some time now,
So in my MS access database i have a
Table named "reservations" and inside the table are
Name(sid,jen)
Roomtype(single,double)
Arrivaldate(3/20/17, 3/20/17 )
Departuredate(3/21/17, 3/21/17)
And in my visual studio form i have
2 labels = lblsingle , lbldouble
1 button named btnok and
Datetimepicker named Datetimepicker1 (properties format set to "Short")
So here is my code:
Private sub Form1_Load
Dim time as DateTime = DateTime.Now
Dim format As String = "MM/d/yyyy"
Datetimepicker1.Text = time.ToString(format)
Private sub btnok_click
Con.open
Dim cmb As new OleDbCommand("SELECT COUNT (*) FROM [reservations] WHERE [Roomtype] = 'Single' AND [Arrivaldate] = " & Datetimepicker1.Text & " ",Con)
Dim dr As OleDbDataReader = cmb.ExecuteReader
Dim userfound As Boolean = False
While dr.Read
userfound = True
lblsingle.text = (dr(0).ToString())
End While
Con.Close()
End Sub
End Class
.
So what i want to happen is when i choose date 3/20/17 in my datetimepicker1. my lblsingle.text should count to "1" because in my database there is a single with the same date as my datetkmepicker1. But the result is "0"......... i really think there is something that makes my datetimepicker1 and the date in my ms access different,,
Please help.... do i need to change time format somewhere?

Answer 1

First your "Private sub btnok_click" will not handle the button click.
To handle "button click" your implementation should be as shown below (proto):
Private Sub button1_Click(sender As Object, e As System.EventArgs) Handles button1.Click
..
..
..
..
End Sub.
Coming to business logic:
When you want to update/increment your label?
Based on the description in your question, you want to update/increment the label as soon as your "DatTimePicker" value is changed.
But in code you are trying to do it in "Ok" button click.
If you want update the label, when you select a date from "datetimepicker", handle below event (proto):
Private Sub DateTimePicker1_ValueChanged(sender as Object, e as EventArgs) _
Handles DateTimePicker1.ValueChanged
..
..
..
..
End Sub

Answer 2

You must handle dates as datetime and not text:
Dim time as DateTime = DateTime.Today
Dim format As String = "yyyy'/'MM'/'/dd"
Datetimepicker1.Value = time
Private sub btnok_click
Con.open
Dim cmb As new OleDbCommand("SELECT COUNT (*) FROM [reservations] WHERE [Roomtype] = 'Single' AND [Arrivaldate] = #" & time.ToString(format) & "# ",Con)

Answer 3

Do not use text representations of date and time - use DateTime for all purposes except rendering output for your users (or serializing as text output like CSV files).
Handling DateTime values for your control
Use the .Value property to get and set your controls value:
Datetimepicker1.Value = DateTime.Now
Handling DateTime values for your database query
Use a (typed) parameter to pass DateTime values to your database query:
Dim cmb As new OleDbCommand("SELECT COUNT (*) FROM [reservations] WHERE [Roomtype] = 'Single' AND [Arrivaldate] = ?", Con)
cmb.Parameters.Add(Datetimepicker1.Value)
OleDbCommand uses positional parameters - that means you need to match the order of your placeholders when adding parameters:
Dim roomtype As String
roomtype = "Single"
Dim cmb As new OleDbCommand("SELECT COUNT (*) FROM [reservations] WHERE [Roomtype] = ? AND [Arrivaldate] = ?", Con)
cmb.Parameters.Add(roomtype)
cmb.Parameters.Add(Datetimepicker1.Value)
Simplify retrieving scalar results like count(*)
If all you try to get is the count(*), you don't need a OleDbDataReader - let your command ExecuteScalar
lblsingle.Text = cmb.ExecuteScalar()