Question

when i click on a button it should save the changes i’ve made to a database, this is the code of the button:

DataRow drow = sql.ds.Tables["Stagiaire"].NewRow();
        Boolean allowAdd = false;
        if (nom.Text != "" && prenom.Text != "")
            allowAdd = true;
        if (allowAdd)
        {
            drow[1] = imgData;
            drow[2] = nom.Text.ToUpper();
            drow[3] = prenom.Text;
            drow[4] = sexe.SelectedItem.ToString();
            drow[5] = naiss.Text;
            drow[6] = email.Text;
            drow[7] = tele.Text;
            drow[8] = adresse.Text;
            drow[9] = niveau.Text;
            drow[10] = filiere.Text;
            drow[11] = stage.SelectedItem.ToString();
            drow[12] = service.SelectedItem.ToString();
            drow[13] = encadrant.SelectedItem.ToString();
            drow[14] = etablissement.SelectedItem.ToString();
            sql.ds.Tables["Stagiaire"].Rows.Add(drow);
            SqlCommandBuilder cmb = new SqlCommandBuilder(daStagiaire);
            daStagiaire.Update(sql.ds, "Stagiaire");
            XtraMessageBox.Show("Bien Ajouter !");
        }

My question is : How can i insert NULL values to the database if the text controllers are empty

Answer 1

For each of the fields you need to check if the string contains a value. If it has a value, then pass that value, if it does not have a value, then pass the NULL.

drow[1] = string.IsNullOrWhitespace(imgData)
           ? (object) imgData : DBNull.Value;

drow[2] = string.IsNullOrWhitespace(nom.Text)
           ? (object) nom.Text.ToUpper : DBNull.Value;

… do the same logic to the rest of the items.

Here I am using a single line IF THEN statement. Take a look at
One-liner if statements, how to convert this if-else-statement for more information.