C#

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.

...
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