C#

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.

...
sql_cmd.Parameters.AddWithValue("@Prix_total_HT", total);
sql_cmd = new OleDbCommand(txtQuery, sql_con);
sql_cmd.ExecuteNonQuery();

really thank you for your advice i will inquire to see if the book is available in french. I did a bit of programming at school but not the csharp, and since it is a langauge that I am passionate about, I decided to take it easy but I really want to know the role of each method used. And for its I thank you again because I followed your advice. But with your permission I would like to send you some project that I have realized thanks to courses on Csharp to just give me your opinion on the presentation of my codes and if there is an improvement to be made.

it does not matter sir I understand you but nevertheless if I have a problem I will post it for a possible help

ago2486 wrote:

'No value given for one or more of the required parameters.'

OriginalGriff wrote:

Look at his code

catch(OleDbException ex)
                      {
                          MessageBox.Show(ex.Source);
                      }

catch(Exception ex)
                      {
                          MessageBox.Show(ex.ToString());
                      }

Hello sir and thank you for the info, I think I saw it when I was doing my research. And it was written only to see the problems with connection to the database. So I would like to know if we could use it only at the connection of the database or not?

thank you sir i will do it now

using (var cmd = sql_con.CreateCommand())
{
    cmd.CommandText = "INSERT INTO Commandes (montant_com) VALUES (@montant_com)";
    cmd.Parameters.AddWithValue("@montant_com", TxtTotalCmd.Text);
    cmd.ExecuteNonQuery();
}

long numCmd;
using (var cmd = sql_con.CreateConnection())
{
    cmd.CommandText = "SELECT MAX(num_com) AS dernier_num FROM Commandes";
    
    object result = cmd.ExecuteScalar();
    if (result is null || Convert.IsDBNull(result))
    {
        numCmd = 0L;
    }
    else
    {
        numCmd = Convert.ToInt64(result);
    }
}

Hello sir and thank you for your help. I did as you advised me but I have a microsoft jet engine error. I will see another tutorial on this subject if I will find a solution ...