Imports System.Data.SqlClient
Public Class Form1
    Dim tblCustomer As New DataTable
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        CreateDatagridColumns()
        fillDatagridview()
    End Sub


    Private Sub CreateDatagridColumns()
        Dim cbColumn As New DataGridViewComboBoxColumn
        Dim cs = connectionObject.GetConnectionString
        Dim tblLocation As New DataTable
        Using connection As New SqlConnection(cs)
            connection.Open()
            Dim cmd = connection.CreateCommand()
            cmd.CommandText = "SELECT Distinct Kota FROM dbo.Customer" 'query1
            tblLocation.Load(cmd.ExecuteReader)
        End Using
        With cbColumn
            .DataSource = tblLocation
            .DisplayMember = "Kota" '<< harus sama dengan query1
            .DataPropertyName = "Kota" '<<harus sama dengan  query2
            .HeaderText = "Asal"
            .Name = "KotaCol"
        End With

        With dgvCustomer
            .Columns.Add(New DataGridViewTextBoxColumn With {.HeaderText = "Id", .DataPropertyName = "ID", .Name = "idCol"})
            .Columns.Add(New DataGridViewTextBoxColumn With {.HeaderText = "Nama Customer", .DataPropertyName = "Nama", .Name = "NamaCol"})
            .Columns.Add(cbColumn)
        End With
    End Sub
    Private Sub fillDatagridview()
        Dim connectionString = connectionObject.GetConnectionString()
        Using connection As New SqlConnection(connectionString)
            connection.Open()
            Dim cmd = connection.CreateCommand()
            cmd.CommandText = "SELECT ID, Nama, Kota FROM dbo.Customer" 'query2
            tblCustomer.Load(cmd.ExecuteReader())
            dgvCustomer.DataSource = tblCustomer
        End Using
    End Sub

End Class