VB.Net Combo Box Number from Query - sql

Question

So i have a database with 2 rows code,name lets say its like
code / name
1 / john
2 / george
i use this query to bring them in my combo box .
strConnection = String.Format("Provider=SQLOLEDB;Data Source={0};Initial Catalog={1};User ID={2};Password={3};",
strServer, strDataBase, strUserName, strPassword)
Dim Connection As New OleDbConnection(strConnection)
Connection.Open()
Dim cm As New OleDbCommand("SELECT Codeid [Κωδικός],descr [Περιγραφή] FROM EMBONILO_B.DBO.manufacturer GROUP BY Codeid,descr", Connection)
Dim dr As OleDbDataReader = cm.ExecuteReader
While dr.Read
ComboBox.Items.Add(dr(1).ToString)
End While
dr.Close()
Connection.Close()
and it show the name john and george. What i want is when you click the combo box and you select a name i want the code to appear on the combo box lets say if its george selected i want number 2 in combo box etc.
Thanks for advance.

Answer 1

When you are adding items to the ComboBox you are only setting the Text property, not the Value property. ComboBox.Items.Add() should have an overload where you can do specify the Value as well when you had items in your While loop, something like ComboBox.Items.Add(dr(1).ToString(), dr(0).ToString()) or maybe ComboBox.Items.Add(New ListItem(dr(1).ToString(), dr(0).ToString())) if you are using ASP.NET WebForms for example. Either way, each list item will have separate Text and Value properties; you want to put the ID in the Value property, and you can subsequently get the selected ID in your code using ComboBox.SelectedValue or similar, depending upon the control you are using for a combobox.
My assumption is you really want to obtain the ID in code to store in a db table, not display it in the UI.

Answer 2

This all applies to a WinForms application.
Declare a Form level variable to hold the CodeID of the currently selected descr in the combobox.
Since GetDescriptionData is called from Form.Load the values strServer, strDatabase etc. used in the connection string, must be available at this time. If they are not available until some user input is gathered move the code to a button. .DisplayMember and .ValueMember are names of fields from the Select statement.
Separate the data access code from the user interface code. Connections and commands need to be closed and disposed. Using...End Using blocks take care of that for us.
The form level variable CurrentCodeID is set in the ComboBox.SelectedIndexChanged event.
Private CurrentCodeID As String
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim ComboDataTable = GetDescriptionData()
ComboBox1.DisplayMember = "descr"
ComboBox1.ValueMember = "Codeid"
ComboBox1.DataSource = dt
End Sub
Private Function GetDescriptionData() As DataTable
Dim dt As New DataTable
Dim strConnection = String.Format("Provider=SQLOLEDB;Data Source={0};Initial Catalog={1};User ID={2};Password={3};",
strServer, strDataBase, strUserName, strPassword)
Using Connection As New OleDbConnection(strConnection),
cm As New OleDbCommand("SELECT Codeid,descr FROM EMBONILO_B.DBO.manufacturer;", Connection)
Connection.Open()
dt.Load(cm.ExecuteReader)
End Using
Return dt
End Function
Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
CurrentCodeID = ComboBox1.SelectedValue.ToString
End Sub