how fill combobox with all records of a person from database based on his name on textbox?

Question

here is my code but its retrieve only last record not all

    SqlConnection history= new SqlConnection("Data Source=.;Initial Catalog=db3;Integrated Security=True");
                history.Open();
                SqlCommand histcmd= new SqlCommand("SELECT salary FROM persontable WHERE (Name = @name)", history);
                histcmd.Parameters.AddWithValue("@name", checkname.text);

                SqlDataReader DRhistory= histcmd.ExecuteReader();
                if (DRhistory.Read())
                {
                    combobox.Text = DRhistory.GetValue(0).ToString();


                }
                history.Close();

Answer 1

You need a loop if you want to get all:

List<string> salaryList = new List<string>();
while(DRhistory.Read())
{
    salaryList.Add(DRhistory.GetString(0));
}

To fill a combobox you can either add them in the loop, simpliest approach:

while(DRhistory.Read())
{
    comboBox.Items.Add(DRhistory.GetString(0));
}

or use a BindingSource which you can assign the list as datasource:

BindingSource bs = new BindingSource();
bs.DataSource = salaryList;
comboBox.DataSource = bs;

Answer 2

As an addition to @TimSchmelters answer:

You also need to populate the ComboBox with the objects in the List . Setting the Text property doesn't add the object to the ComboBoxes Item collection.

using(SqlConnection history= new SqlConnection("Data Source=.;Initial Catalog=db3;Integrated Security=True"))
{
     history.Open();
     SqlCommand histcmd= new SqlCommand("SELECT salary FROM persontable WHERE (Name = @name)", history);
     histcmd.Parameters.AddWithValue("@name", checkname.text);
     List<string> salaryList = new List<string>();

     using (SqlDataReader DRhistory = histcmd.ExecuteReader())
     {    
         while(DRhistory.Read())
         {
            salaryList.Add(DRhistory.GetString(0));
         }
     }

     combobox.Items.AddRange(salaryList.ToArray());

     history.Close();
}