SQL QUERY Return 0 Records but 2 records exist - sql

Question

This code returns zero rows count but there are 2 rows in appointment table.
The msgbox I commented was to check if the date is correct and format is correct and shows date as 2014/08/09. The appointment date in database is 2014/08/09 for 2 records (the only 2 records). Record count variable shows 0.
Table name (copied directly cut and paste) is Appointments and column is AppointmentDate.
The connectDatabase sub routine connects to the database successfully as I use it whenever I connect to database so it's correct as I connect to other tables correctly before I run this code using same sub routine.
Command.text contains
SELECT * FROM Appointments WHERE AppointmentDate = 2014/08/09
Don't know what other details to specify.
Private Sub frmAppointments_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'load appointments
LoadAppointments(dtpAppointmentDate.Value.Date)
End Sub
Public Sub LoadAppointments(whichdate As Date)
Dim sqlcmd As New OleDb.OleDbCommand
'set connection
ConnectDatabase()
With frmAppointments
'MsgBox(whichdate)
M_connDB.Open()
'fetch records from database
sqlcmd.Connection = M_connDB
sqlcmd.CommandText = "SELECT * FROM Appointments WHERE AppointmentDate = " & whichdate
.dataAdapterAppointments = New OleDb.OleDbDataAdapter(sqlcmd.CommandText, M_connDB)
'first clear data table to prevent duplicates
.dataTableAppointments.Rows.Clear()
.dataAdapterAppointments.Fill(.dataTableAppointments)
M_connDB.Close()
Dim rowindex As String
Dim iy As Long
Dim recordcount As Long
'check if any records exist
recordcount = .dataTableAppointments.Rows.Count
If Not recordcount = 0 Then
For iy = 0 To .dataTableAppointments.Rows.Count
For Each row As DataGridViewRow In .dtgrdAppointments.Rows
If row.Cells(0).Value = .dataTableAppointments.Rows(iy).Item(6) Then
rowindex = row.Index.ToString()
MsgBox(.dtgrdAppointments.Rows(rowindex).Cells(0).Value, vbInformation + vbOKOnly, "MSG")
Exit For
End If
Next
Next iy
Else
MsgBox("No Appointments for selected date.", vbInformation + vbOKOnly, "No Appoinments")
End If
End With

Answer 1

Use sql-parameters instead of string-concatenation. This should work in MS Access:
sqlcmd.CommandText = "SELECT * FROM Appointments WHERE AppointmentDate = ?"
sqlcmd.Parameters.AddWithValue("AppointmentDate", whichdate)
This prevents you from conversion or localization issues and -even more important- sql-injection.

Answer 2

2014/08/09 doesn't have quotes around it, making it a math expression (2014 divided by 8 divided by 9). Of course, your table has no rows with a date matching the result of that expression. But don't put in the quotes. Instead, add a parameter.

Answer 3

I don't VB, so I write it in C#. My point of view is it's better to specify the datatype too:
sqlcmd.CommandText = "SELECT * FROM Appointments WHERE AppointmentDate=#whichdate";
sqlcmd.Parameters.Add("#whichdate", SqlDbType.Date).Value = whichdate;