parameterized query........ unexpected in database using C#

Question

Hello there I am trying to enter database records from window Form design and programmed using MS visual C# and it approved and entered database using an other Window Form and I call the child Form using showDialog , I tried to make it entering to and sending thde data using string array and send it as following

    public string[] cashg1
    {
        get { return dt; }
        set { dt = value; }
       }
          public void Entering(){
              form2.ShowDialog();
              string[] inputs = new string[10];
              DateTime Date = DateTime.Today;
              inputs[0] = numb.Text;
              inputs[1] = comboBox1.SelectedText;
              inputs[2] = owner.Text;
              inputs[3] = curency.Text;
              inputs[4] = curncyval.Text;
              inputs[5] = Depet.Text;
              inputs[6] = cridet.Text;
              inputs[7] = Convert.ToString(Date);
              inputs[8] = note.Text;

              form2.addingdata(inputs);
              cashg1 = inputs;
              }




            public void Entring_to database(){inputs = new string[10];
        using (SqlConnection connection = new SqlConnection(connectionString))
        {

            DateTime Date = DateTime.Today;
            try
            {

                SqlCommand cmd = new SqlCommand("INSERT INTO   Accont(Account_ID,Account_Name,Owners,Curency,Curncytype,Depet,Credet_devet,Date,Note) VALUES ( @@AccountID, @AccountName, @Owner, @Curncy,@Curncytype,@Depet,@Cridetdevet,@Date,@Note)");
                cmd.CommandType = CommandType.Text;
                cmd.Connection = connection;
                cmd.Parameters.AddWithValue("@@AccountID", Convert.ToInt32(inputs[0]));
                if (String.IsNullOrEmpty(inputs[0]))
                    inputs[0] = "323";
                cmd.Parameters.AddWithValue("@AccountName", Convert.ToString(inputs[1]));
                if (String.IsNullOrEmpty(inputs[1]))
                    inputs[1] = "        ";
                cmd.Parameters.AddWithValue("@Owner", inputs[2]);
                cmd.Parameters.AddWithValue("@Curncy", inputs[3]);
                cmd.Parameters.AddWithValue("@Curncytype", inputs[4]);
                cmd.Parameters.AddWithValue("@Depet", inputs[5]);
                cmd.Parameters.AddWithValue("@Cridetdevet", inputs[6]);
                cmd.Parameters.AddWithValue("@Date", Date);
                cmd.Parameters.AddWithValue("@Note", inputs[7]);
                connection.Open();//Owner
                cmd.ExecuteNonQuery();


            }
            catch (Exception ee)
            {
                MessageBox.Show("Error  :" + ee.Message);
            }
        }
      }
     }

I enter my data using this Form: when I clicked conforming button to enter the data in datagridview After conforming the data must enter the database but It dosenot enter and gives my this error

thank you for helping

Answer 1

AddWithValue will not add parameter, if value is null.

If setting AccountName to blank instead of null is intended, then you should change order of these strings in your code (i.e. you should initialize inputs1 if it is empty before adding this parameter, not after)

Your code

cmd.Parameters.AddWithValue("@AccountName", Convert.ToString(inputs[1]));
if (String.IsNullOrEmpty(inputs[1]))
  inputs[1] = "        ";

Should looks like

if (String.IsNullOrEmpty(inputs[1]))
  inputs[1] = "        ";
cmd.Parameters.AddWithValue("@AccountName", Convert.ToString(inputs[1]));

Instead, if null should be inserted in database if inputs1 is empty, you should use DBNull.Value

cmd.Parameters.AddWithValue("@AccountName", inputs[1] == null ? DBNull.Value : Convert.ToString(inputs[1]));

See msdn for reference.