C#

thank you for your answer but I wanted to point out that (num_com) is auto-incremente. I would like to know if that doesn't count?

OK well sir and I just found her in my research, are I adapting well to my code?
  using (OleDbCommand cmd1 = sql_con.CreateCommand ())
                     {
                        
                         cmd1.CommandText = "INSERT INTO Orders (amount_com) VALUES (@montant_com)";
                         cmd1.CommandText = "SELECT @@ IDENTITY";
                         int id = Convert.ToInt32 (cmd1.ExecuteScalar ());
                         cmd1.Parameters.AddWithValue ("@ amount_com", TxtTotalCmd.Text);
                         cmd1.ExecuteNonQuery ();
                     }

Ok my apologies, this is the error I get
System.Data.Oledb.Ole Exception (0x80040E14): Character found after the end of the Sql instruction

using (OleDbCommand cmd1 = sql_con.CreateCommand())
                   {

                       cmd1.CommandText = "INSERT INTO Commandes (montant_com) VALUES (@montant_com);" + "SELECT SCOPE_IDENTITY()";

                       int id;
                       cmd1.Parameters.AddWithValue("@montant_com", TxtTotalCmd.Text);

                       cmd1.ExecuteNonQuery();
                       id = (int)cmd1.ExecuteScalar();
                       TxtNunCmd.Text = id.ToString();

                   }

I just did it but I have an error: the function 'SCOPE_IDENTITY' not defined in the expression

using (OleDbCommand cmd1 = sql_con.CreateCommand())
{

    cmd1.CommandText = "INSERT INTO Commandes (montant_com) VALUES (@montant_com)";
    cmd1.CommandText = "SELECT SCOPE_IDENTITY()";

    cmd1.Parameters.AddWithValue("@montant_com", TxtTotalCmd.Text);

    cmd1.ExecuteNonQuery();
    int id = Convert.ToInt32(cmd1.ExecuteScalar());
    TxtNunCmd.Text = id.ToString();

}

and I wanted to clarify that I am on an access database

it’s already done sir but what I don't understand textbox does not recover the id, it displays zero

using (OleDbCommand cmd1 = sql_con.CreateCommand())
                 {

                     cmd1.CommandText = "INSERT INTO Commandes (montant_com) VALUES (@montant_com)";
                     cmd1.CommandText = "SELECT @@IDENTITY";

                     cmd1.Parameters.AddWithValue("@montant_com", TxtTotalCmd.Text);

                     //sql_cmd = new OleDbCommand(CommandText, sql_con);
                     cmd1.ExecuteNonQuery();
                      id = (int)cmd1.ExecuteScalar();
                     TxtNunCmd.Text = id.ToString();
                 }

:doh:  :doh:  :doh:  :doh: you are right sir and I promise you find the solution and you ride it

yes yes sir I am still looking for, I will find it, I assure you sir

using (OleDbCommand cmd1 = sql_con.CreateCommand())
                   {

                       cmd1.CommandText = "INSERT INTO Commandes (montant_com) VALUES (@montant_com)";
                       OleDbCommand cmr = sql_con.CreateCommand();
                       cmr.CommandText = "SELECT @@IDENTITY AS LastId";

                       cmd1.Parameters.AddWithValue("@montant_com", TxtTotalCmd.Text);
                       id = (int)cmr.ExecuteScalar();
                       TxtNunCmd.Text = id.ToString();

                       cmd1.ExecuteNonQuery();

                   }

but i can't get the id

Hello sir and all my excuses for yesterday I had a connection problem that's why I disconnected but by dint of fighting all night I could find the solution regaré and tell me if the code is clean. I must say I am glad I did ...

using (OleDbCommand cmd1 = sql_con.CreateCommand())
                  {

                      cmd1.CommandText = "INSERT INTO Commandes (montant_com) VALUES (@montant_com)";
                      cmd1.Parameters.AddWithValue("@montant_com", TxtTotalCmd.Text);
                      cmd1.ExecuteNonQuery();
                      OleDbCommand cmr = sql_con.CreateCommand();
                      cmr.CommandText = "SELECT @@IDENTITY AS LastId";


                      int LastId = Convert.ToInt32(cmr.ExecuteScalar());
                      TxtNunCmd.Text = LastId.ToString();
                      //sql_cmd = new OleDbCommand(CommandText, sql_con);


                  }

SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'

SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;--'

SELECT * FROM MyTable WHERE StreetAddress = 'x';

DROP TABLE MyTable;

--'