Question

I have a ComboBox with its elements loaded from a sqlserver table (groups).
I also have a DataGridView, linked to another table (users).

When I load the form, the combo is filled with groups, and the datagridview is filled with users (all the users)

1) I want to be able to select a group from the ComboBox (dropDownList), and then to refresh the DataGridView with the users that belong to that selected group…

2) And How can I show a join relation in the DataGridView? Let’s say I want to show the groupName in the last column of the each user…

PS:

I have an xsd Dataset created in my VS2008 project with its
corresponding tableAdapters generated
(groupTableAdapter, userTableAdapter)
and some sql-methods added to each
adapter

Answer 1

1) Set up a BindingSource for both tables.

BindingSource bsGroup = new BindingSource();
BindingSource bsUser  = new BindingSource();
bsGroup.DataSource = MyDataSet.Tables["Group"];
bsUser.DataSource = MyDataSet.Tables["User"];

2) Set up your Combo and Grid DataSources.

MyCombo.DataSource    = bsGroup;
MyCombo.DisplayMember = "GroupName"; // whatever your ColumnName is
MyCombo.ValueMember   = "GroupID";
MyGrid.DataSource = bsUser;

3) Set up a SelectedIndexChanged event for the Combo and use it to change the filter on the bsUser bindingsource.

MyCombo.SelectedIndexChanged += new System.EventHandler(MyCombo_SelectedIndexChanged);
private void MyCombo_SelectedIndexChanged(object sender, System.EventArgs e)
{
    // this will depend on what your column names are, obviously
    string filter = string.Format("GroupID = {0}", MyCombo.SelectedValue);
    bsUser.Filter = filter;
}

This worked fine… taken from here.

(Yes, I posted this also on MSDN because I was in a hurry)