VB.Net binding datagridview Comboboxcolumn to datagridviewTextboxColumn

Question

I am loading data from two tables: institute and country. Institute has 3 columns: instId, name, countryId. And country has 2 columns: countryId, name where countryId is a foreign key from country table. I fill these two tables in dataset. I have datagridview and set its datasource to institute table in my dataset. I also create datagridviewcomboboxcolumn and bind it country table. Have a look to the following code:

    Public Class frmDGV

    Dim sqlConn As SqlConnection
    Dim dsOptions As DataSet
    Dim daInstitute As SqlDataAdapter
    Dim daAdapter As SqlDataAdapter
    Dim bsCountry As BindingSource

    Private Sub frmTest_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Try
            dsOptions = New DataSet
            loadOptions()

            dgvInstitute.DataSource = dsOptions.Tables("institute")
            bsCountry = New BindingSource(dsOptions, "country")

            Dim col As New DataGridViewComboBoxColumn
            col.DataPropertyName = "countryName"
            col.HeaderText = "Country"
            col.Name = "cName"

            col.DataSource = bsCountry
            col.DisplayMember = "countryName"
            col.ValueMember = "countryId"

            dgvInstitute.Columns.Add(col)
            dgvInstitute.Columns(0).Width = 60
            dgvInstitute.Columns(1).Width = 200
            dgvInstitute.Columns(2).Width = 60
            dgvInstitute.Columns(3).Width = 120

        Catch ex As Exception
            MsgBox(Err.Description)
        End Try
    End Sub

    Sub loadOptions()
        Dim sql As String

        Try
            sqlConn = New SqlConnection(connString)
            sqlConn.Open()

            sql = "select instId, name, countryId from institute"
            daInstitute = New SqlDataAdapter(sql, sqlConn)
            daInstitute.Fill(dsOptions, "institute")
            '----------------------------------------------------------------------

            sql = "select countryId, countryName from country"
            daAdapter = New SqlDataAdapter(sql, sqlConn)
            daAdapter.Fill(dsOptions, "country")
            '----------------------------------------------------------------------

            sqlConn.Close()
        Catch ex As Exception
            sqlConn.Close()
            MsgBox(Err.Description)
        End Try
    End Sub
End Class

How can I display the proper country name in the combobox based on the countryId in the datagridview using the binding techniques not using a loop? See the following picture:

Answer 1

Change DataPropertyName for comboboxcolumn in your datagridview:

...
col.DataPropertyName = "countryId"
...

.DataPropertyName - is a column name from datagridview.DataSource,which you want to show in the current column.