c# winforms closing

Question

Hi ,
Please I am using following program and save data into database from datatable when I run the program its exit but not save the data, while I will remove this.close() its save although I placed this.close() at end of program.
thank you

      public void SaveUsingOracleBulkCopy(DataTable dt)
        {
            try
            {
                using (var connection = new OracleConnection(connectionString))
                {
                    connection.Open();
                    int[] ids = new int[dt.Rows.Count];
                    string[] names = new string[dt.Rows.Count];
                    string[] addresses = new string[dt.Rows.Count];

                    for (int j = 0; j < dt.Rows.Count; j++)
                    {
                        ids[j] = Convert.ToInt32(dt.Rows[j]["ID"]);
                        names[j] = Convert.ToString(dt.Rows[j]["NAME"]);
                        addresses[j] = Convert.ToString(dt.Rows[j]["ADDRESS"]);
                    }

                    OracleParameter id = new OracleParameter();
                    id.OracleDbType = OracleDbType.Int32;
                    id.Value = ids;

                    OracleParameter name = new OracleParameter();
                    name.OracleDbType = OracleDbType.Varchar2;
                    name.Value = names;

                    OracleParameter address = new OracleParameter();
                    address.OracleDbType = OracleDbType.Varchar2;
                    address.Value = addresses;

                    // create command and set properties
                    OracleCommand cmd = connection.CreateCommand();
                    cmd.CommandText = "INSERT INTO BULKINSERTTEST (ID, NAME, ADDRESS) VALUES (:1, :2, :3)";
                    cmd.ArrayBindCount = ids.Length;
                    cmd.Parameters.Add(id);
                    cmd.Parameters.Add(name);
                    cmd.Parameters.Add(address);
                    cmd.ExecuteNonQuery();
 this.close();

                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
    }