VB.net Query wont retrieve data from access database - vb.net

Question

I have created a query using vb.net with parameters which should allow the query to retrieve data from my access database but however when I click on the button it only shows blank fields but no rows are retrieved from the database. Could you please help me what I am currently doing wrong.
Imports System.Data.OleDb
Public Class RouteToCruise
Private Sub RouteToCruise_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Private Sub Route_Btn_Click(sender As Object, e As EventArgs) Handles Route_Btn.Click
Try
Dim row As String
Dim connectString As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\DeepBlueTables.mdb"
Dim cn As OleDbConnection = New OleDbConnection(connectString)
cn.Open()
Dim CruiseQuery As String = "SELECT Route.RouteName + ', ' + Cruise.CruiseID As CruiseRoute FROM Route INNER JOIN Cruise ON Route.RouteID = Cruise.RouteID WHERE CruiseID = ?"
Dim cmd As New OleDbCommand(CruiseQuery, cn)
'cmd.Parameters.AddWithValue("CruiseID", OleDbType.Numeric).Value = Route_Txt.Text
cmd.Parameters.AddWithValue(("CruiseID"), OleDbType.Numeric)
Dim reader As OleDbDataReader = cmd.ExecuteReader
'RCTable.Width = Unit.Percentage(90.0)
RCTable.ColumnCount = 2
RCTable.Rows.Add()
RCTable.Columns(0).Name = "CruiseID"
RCTable.Columns(1).Name = "RouteName"
While reader.Read
Dim rID As String = reader("RouteID").ToString()
cmd.Parameters.AddWithValue("?", rID)
row = reader("CruiseID") & "," & ("RouteName")
RCTable.Rows.Add(row)
End While
reader.Close()
cn.Close()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
End Class
If the user enters route name in the text box then the rows should show cruise ID and route name for each of the selected routes. for example if users enters Asia in the text box, clicks on the button then the query should return the cruiseID for the cruises which are going to Asia.

Answer 1

Your use of parameters makes no sense. First you call AddWithValue and provide no value, then you execute the query and then you start adding more parameters as you read the data. Either you call AddWithValue and provide a value, or you call Add and then set the Value on the parameter object created. Either way, it MUST be before you execute the query or it's useless.
myCommand.Parameters.AddWithValue("#ParameterName", parameterValue)
or
Dim myParameter = myCommand.Parameters.Add("#ParameterName", OleDbType.Numeric)
myParameter.Value = parameterValue