Filling ComboBox with DataReader and obtaining the primary key of selected item
SqlConnection cnn;
SqlCommand cmd;
SqlDataReader dr;
private void Form1_Load(object sender, EventArgs e) {
cnn = new SqlConnection("Integrated Security=sspi;Initial Catalog=Northwind");
cnn.Open(); cmd = new SqlCommand("select * from Categories", cnn);
dr = cmd.ExecuteReader();
while (dr.Read())
cboCategories.Items.Add(dr["CategoryName"]);
dr.Close();
}
private void cboCategories_SelectedIndexChanged(object sender, EventArgs e)
{
cmd = new SqlCommand("select CategoryId from Categories where CategoryName = '" + cboCategories.Text + "'", cnn);
dr = cmd.ExecuteReader();
while (dr.Read())
MessageBox.Show(dr["CategoryId"].ToString());
dr.Close();
}