C#

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;

--'

hello sir all my apologies for the delay ... i was putting my code clean as you advised me. I have an error like microsoft jet engine

try
                        {
                            setConnection();
                            sql_con.Open();
                            using (sql_cmd = sql_con.CreateCommand())
                            {
                                string txtQuery = "INSERT INTO Detail_temp (ref_det, qute_det, Designation, Prix_unitaire_HT, Prix_total_HT) VALUES (@ref_det,@qute_det,@Designation,@Prix_unitaire_HT,@Prix_total_HT)";
                                sql_cmd.Parameters.AddWithValue("@ref_det", TxtRefProduit.Text);
                                sql_cmd.Parameters.AddWithValue("@qute_det", TxtQteCmd.Text);
                                sql_cmd.Parameters.AddWithValue("@Designation", TxtDesignation.Text);
                                sql_cmd.Parameters.AddWithValue("@Prix_unitaire_HT", TxtPrixUnitaire.Text);
                                sql_cmd.Parameters.AddWithValue("@Prix_total_HT", total);
                                sql_cmd = new OleDbCommand(txtQuery, sql_con);
                                sql_cmd.ExecuteNonQuery();
                                //ExecuteQuery(txtQuery);
                            }
                        }
                        catch(OleDbException ex)
                        {
                            MessageBox.Show(ex.Source);
                        }

Quote:

I have an error like microsoft jet engine

You are right sir but frankly I don't know how to explain it to you. but once I submit the add button after filling in all the fields as it should be this is the message I receive. And nothing in the access database.

Ok, thank you sir. I removed my block of code in the try and here is the error: at the level of sql_cmd.ExecuteNonQuery ();
System.Data.OleDb.OleDbException: 'No value given for one or more of the required parameters.'

private void BtnAjouter_Click(object sender, EventArgs e)
        {
            int total;
            decimal total_achat;
            //si les champs sont vides
            if (TxtDesignation.Text == "" || TxtPrixUnitaire.Text == "" || TxtQteCmd.Text == "" || TxtQteStock.Text == "" || TxtRefProduit.Text == "")
            {
                MessageBox.Show("Rassurez vous que tous les champs ont bien été rempli.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            else
            {
                //Vérifier si la valeur saisie est numeric
                if (Int32.TryParse(TxtQteCmd.Text, out int value) && TxtRefProduit.Text != "")
                {
                    //Vérifier si la commande est inferieur ou egale au stock
                    int a = 0;
                    int b = 0;
                    int c;

                    //Convertire les textBox en int
                    int.TryParse(TxtQteCmd.Text.Trim(), out a);
                    int.TryParse(TxtQteStock.Text.Trim(), out b);
                    int.TryParse(TxtPrixUnitaire.Text.Trim(), out c);

                    if (a <= b)
                    {
                        total = a * c;
                        total_achat = 0;

                        //try
                       // {
                            setConnection();
                            sql_con.Open();
                           using (sql_cmd = sql_con.CreateCommand())
                            {
                               string txtQuery = "INSERT INTO Detail_temp (ref_det, qute_det, Designation, Prix_unitaire_HT, Prix_total_HT) VALUES (@ref_det,@qute_det,@Designation,@Prix_unitaire_HT,@Prix_total_HT)";
                               sql_cmd.Parameters.AddWithValue("@ref_det", TxtRefProduit.Text);
                               sql_cmd.Parameters.AddWithValue("@qute_det", TxtQteCmd.Text);
                               sql_cmd.Parameters.AddWithValue("@Designation", TxtDesignation.Text);
                               sql_cmd.Parameters.AddWithValue("@Prix_unitaire_HT", TxtPrixUnitaire.Text);
                               sql_cmd.Parameters.AddWithValue("@Prix_total_HT", total);
                               sql_cmd = new OleDbCommand(txtQuery, sql_con);
                               sql_cmd.ExecuteNonQuery();
                                //ExecuteQuery(txtQuery);
                            }
                       // }
                       // catch(OleDbException ex)
                       // {
                            //MessageBox.Show(ex.Source);
                        //}

for me this message means that one of the values entered in the texbox is not loaded in the database suddenly it sees no data in the fields. I have the impression that my fields remain empty after adding

I even tried this if, I have the same error

using (sql_cmd = sql_con.CreateCommand())
                           {
                              string txtQuery = "INSERT INTO Detail_temp (ref_det, qute_det, Designation, Prix_unitaire_HT, Prix_total_HT) VALUES (@ref_det, @qute_det, @Designation, @Prix_unitaire_HT, @Prix_total_HT)";
                             OleDbParameter refprod = sql_cmd.Parameters.AddWithValue("@ref_det", OleDbType.VarChar);
                             refprod.Value = TxtRefProduit.Text;
                             OleDbParameter qtecmd = sql_cmd.Parameters.AddWithValue("@qute_det", OleDbType.VarChar);
                             qtecmd.Value = TxtQteCmd.Text;
                             OleDbParameter design = sql_cmd.Parameters.AddWithValue("@Designation", OleDbType.VarChar);
                             design.Value = TxtDesignation.Text;
                             OleDbParameter prixU = sql_cmd.Parameters.AddWithValue("@Prix_unitaire_HT", OleDbType.Integer);
                             prixU.Value = TxtPrixUnitaire.Text;
                             OleDbParameter prixT = sql_cmd.Parameters.AddWithValue("@Prix_total_HT", OleDbType.Integer);
                             prixT.Value = total;


                              sql_cmd = new OleDbCommand(txtQuery, sql_con);
                              sql_cmd.ExecuteNonQuery();

                           }

sql_cmd = new OleDbCommand(txtQuery, sql_con);

answer 4

Quote:

Extra hint: It's less than (3) and greater than (1).

Can you explain it to me please? I'm just a beginner who learns through some tutorials

List<string> myList = new List<string>();
myList.Add("One");
myList.Add("Two");
myList.Add("Three");
myList.Add("Four");
myList.Add("Five");
foreach (string s in myList)
    {
    Console.WriteLine(s);
    }

One
Two
Three
Four
Five

List<string> myList = new List<string>();
myList.Add("One");
myList.Add("Two");
myList.Add("Three");
myList.Add("Four");
myList.Add("Five");
myList = new List<string>();
foreach (string s in myList)
    {
    Console.WriteLine(s);
}

you are right sir I doubted but after having compiled I realized that the variable s is empty.