How do i show my data from a table in database with specific position to a combobox? example is this Example

Only with the President Position candidates will appear on combobox1 from table1 Only with the VPresident Position candidates will appear on combobox2 from table1 and so on...

im stuck with this on combobox1 which is called prescombo code

Private Sub prescombo_SelectedIndexChanged(sender As Object, e As EventArgs) Handles prescombo.SelectedIndexChanged
        Try
            Dim query As String = "SELECT * FROM Candidates WHERE Position = President"
            Using con As SqlConnection = New SqlConnection("Data Source=EXPOOKY;Initial Catalog=SchoolDB;Integrated Security=True")
                Using cmd As SqlCommand = New SqlCommand(query, con)
                    Dim datapter As SqlDataAdapter = New SqlDataAdapter(cmd)
                    Dim datable As DataTable = New DataTable()
                    datapter.Fill(datable)
                    prescombo.DisplayMember = "CandidateName"
                    prescombo.ValueMember = "CandidateID"
                    If datable.Rows.Count > 0 Then
                        If datable.Rows(3)("Position") = "President" Then
                            presparty.Text = datable.Rows(3).Item("Position").ToString
                        End If
                    End If
                End Using
            End Using
        Catch ex As Exception

        End Try
    End Sub

This is what i tried based on my logic and its not working

CodePudding user response：

If you're filtering the data using a WHERE clause in the query then there's no need to check the records in the result set. Just populate the DataTable and bind it.

Dim query = "SELECT * FROM Candidates WHERE Position = 'President'"
Dim connectionString = "Data Source=EXPOOKY;Initial Catalog=SchoolDB;Integrated Security=True"

Using adapter As New SqlDataAdapter(query, connectionString)
    Dim table As New DataTable

    adapter.Fill(table)

    With prescombo
        .DisplayMember = "CandidateName"
        .ValueMember = "CandidateID"
        .DataSource = table
    Endf With
End Using