C＃在其中填充datagridview和组合框

Question

I know how to populate datagridview, but I'm not sure how should I implement (at same time) the fill of a combobox according to the values of the first query.

query = "SELECT std.id, std.firstname, std.lastname, y.description
         FROM students AS std
         INNER JOIN years AS y ON y.id = std.id";
dAdapter = new OleDbDataAdapter(query, connection);
dset = new DataSet();

dAdapter.Fill(dset, "students");
dataGridView1.DataSource = dset.Tables["students"];

This works ok..but the data inside the datagridview is all Textbox. Although the year column should be a combobox, since there are two or more items.

    ID | Description
 ---------------------
     1 | First Grade
     2 | Second Grade

Thus said, I also would like the year to match the query.

ID | FirstName | LastName | Year (Combobox)
--------------------------------------------
 1     John       Lenon      Second Grade
 2     Maria      Keyl       Second Grade
 3     Stack      Overflow   First Grade

How can I accomplish this?

EDIT 1: Ok, I'm getting somewhere.

string query = "SELECT std.id, std.std_name, std.std_last, y.id AS [yearID], y.description AS [yearDescription]" +
               "FROM students AS std " +
               "INNER JOIN years AS y ON y.id = std.year_id";
dAdapter = new OleDbDataAdapter(query, connection);
dset = new DataSet();

dAdapter.Fill(dset, "students");
dataGridView1.AutoGenerateColumns = false;
dataGridView1.DataSource = dset.Tables["students"];

var id = new DataGridViewTextBoxColumn
{
    DataPropertyName = "id",
    HeaderText = "#",
    Name = "id",
};

dataGridView1.Columns.Add(id);

DataGridViewComboBoxColumn years = new DataGridViewComboBoxColumn();

years.HeaderText = "Year";
years.DataSource = dset.Tables["students"];
years.DataPropertyName = "yearID";
years.ValueMember = "yearID";
years.DisplayMember = "yearDescription";

dataGridView1.Columns.Add(years);

This works..the only problem I have now is that if I change the combobox index to another it doesn't change, it's kind of frozen. Any idea?

Answer 1

The value in years.DataSource should be different than the "students" table.

You're indicating where the ComboBox should get its available years from. For example, if you only wanted 1998 - 2000 in the drop-down, you could use something as simple as this:

years.DataSource = new List<int>{ 1998, 1999, 2000 };

If you wanted to quickly add all years between, say, 2000 - 2099, you could use this:

years.DataSource = Enumerable.Range(2000, 100);