C#

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 ...

ok thank you sir. But there is not much detail except that when I submit the button to add I receive the message microsoft jet engine.

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);
                       }

                       //Création de la requête sql pour inserer des valeurs dans DB
                      //string txtQuery = "INSERT INTO Detail_temp (ref_det, qute_det, Designation, Prix_unitaire_HT, Prix_total_HT) VALUES ('"+ TxtRefProduit.Text+ "', '" + TxtQteCmd.Text + "', '" + TxtDesignation.Text + "', '" + TxtPrixUnitaire.Text + "', '" + total + "')";

                      //ExecuteQuery(txtQuery);

                       try
                       {

                           LoadDB();

                           //ADDITIONNER UNE COLONNE DU DATAGRIDVIEW
                           for (int i = 0; i < dataGridView1.Rows.Count; i++) //Car tu fais une infériorité stricte
                           {
                               total_achat += Convert.ToDecimal(dataGridView1.Rows[i].Cells[4].Value);

                           }
                           TxtTotalCmd.Text = total_achat.ToString();//convertir total_achat en string^pour pouvoir l'afficher dans le textbox
                           TxtDesignation.Text = "";
                           TxtQteCmd.Text = "";
                           TxtPrixUnitaire.Text = "";
                           TxtRefProduit.Text = "";
                           TxtQteCmd.Text = "";
                           //SupDetail_Temp();

                       }

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

                   }
                   else
                   {
                       MessageBox.Show("Veuillez verifier le stock du produit!!!");
                   }
               }

           }

       }

I followed your advice, sir, regarding possible SQL injection. I may be wrong but I made the parameter request as you told me, but if he has other errors, can you help me please

thank you sir i was afraid i didn't do what you told me.

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);
                       }



                       try
                       {

                           LoadDB();

                           //ADDITIONNER UNE COLONNE DU DATAGRIDVIEW
                           for (int i = 0; i < dataGridView1.Rows.Count; i++) //Car tu fais une infériorité stricte
                           {
                               total_achat += Convert.ToDecimal(dataGridView1.Rows[i].Cells[4].Value);

                           }
                           TxtTotalCmd.Text = total_achat.ToString();//convertir total_achat en string^pour pouvoir l'afficher dans le textbox
                           TxtDesignation.Text = "";
                           TxtQteCmd.Text = "";
                           TxtPrixUnitaire.Text = "";
                           TxtRefProduit.Text = "";
                           TxtQteCmd.Text = "";
                           //SupDetail_Temp();

                       }

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

                   }
                   else
                   {
                       MessageBox.Show("Veuillez verifier le stock du produit!!!");
                   }
               }

           }

       }

Quote:

C#

// 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);
}

1. Creates a string variable to hold the query;
2. Adds 5 parameters to the sql_cmd variable;
3. Throws the sql_cmd variable away and sets it to a new OleDbCommand instance;
4. Attempts to execute the sql_cmd without adding any parameters to it;

using (OleDbCommand cmd = sql_con.CreateCommand())
{
    cmd.CommandText = "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)";
    
    cmd.Parameters.AddWithValue("@ref_det", TxtRefProduit.Text);
    cmd.Parameters.AddWithValue("@qute_det", TxtQteCmd.Text);
    cmd.Parameters.AddWithValue("@Designation", TxtDesignation.Text);
    cmd.Parameters.AddWithValue("@Prix_unitaire_HT", TxtPrixUnitaire.Text);
    cmd.Parameters.AddWithValue("@Prix_total_HT", total);
    
    sql_con.Open();
    cmd.ExecuteNonQuery();
}

Thank you very much to you I try it and I come back to you

and here is my connection

private void setConnection()
     {
         try
         {
             string connetionString = null;
             //connection à la base de donnée avec mot de passe
             connetionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data source=" + Application.StartupPath + @"\DB_CaisseEnregistreuse.mdb;Persist Security Info=True;Jet OLEDB:Database Password=B@sta08091987";
             sql_con = new OleDbConnection(connetionString);
         }
         catch (Exception ex)
         {
             MessageBox.Show("Erreur de connexion à la base donnée" + ex.Message);
         }


     }

System.Data.OleDb.OleDbException: 'No value given for one or more of the required parameters.'