how to fill combobox

Question

I am trying to fill ComboBox with the data that is come from DataBase but i am facing this error that is:

Cannot set column 'yer'. The value violates the MaxLength limit of this column.

my code is:

try
                {
                    cmd = new SqlCommand("SELECT SUBSTRING(CONVERT(nvarchar(50),VSDateTiime,105),7,4) as yer FROM SessionDetails where VSNo=@VSNo group by VSDateTiime order by yer desc", con);
                    cmd.Parameters.AddWithValue("@VSNo", cmbVSNo.SelectedValue);
                    if (con.State == ConnectionState.Closed)
                    {
                        con.Open();
                    }
                    SqlDataReader rd = cmd.ExecuteReader();
                    if (rd.HasRows)
                    {
                        cmbVSYear.Items.Clear();
                        DataTable dt = new DataTable();
                        dt.Load(rd);
                        DataRow dr = dt.NewRow();
                        dr["yer"] = 0;
                        dr["yer"] = "--Select--";

                        dt.Rows.InsertAt(dr, 0);
                        cmbVSYear.DataSource = dt;
                        cmbVSYear.ValueMember = "yer";
                        cmbVSYear.DisplayMember = "yer";
                    }
                    else
                    {
                        cmbVSYear.Items.Clear();
                        cmbVSYear.Items.Insert(0, "Record not found");
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
                finally
                {
                    if (con.State == ConnectionState.Open)
                    {
                        con.Close();
                    }
                }

i am working in c# .net windows form application Please give me solution..

Answer 1

When you load datatable form SqlDataReader, it automatically assigns MaxLength to "yer" column which you have retrieved from database.

SUBSTRING(CONVERT(nvarchar(50),VSDateTiime,105),7,4)

Restricts yer column MaxLength to 4.

You could change max length using DataColumn.MaxLength Property:

DataTable dt = new DataTable();
dt.Load(rd);
dt.Columns["yer"].MaxLength = 10;  //or greater