c# - How to insert data into SQL Server

Question

What the problem on my coding? I cannot insert data to ms sql.. I'm using C# as front end and MS SQL as databases...

name = tbName.Text;
userId = tbStaffId.Text;
idDepart = int.Parse(cbDepart.SelectedValue.ToString());

string saveStaff = "INSERT into tbl_staff (staffName,userID,idDepartment) " +
                   " VALUES ('" + name + "', '" + userId +"', '" + idDepart + "');";

SqlCommand querySaveStaff = new SqlCommand(saveStaff);

try
{
querySaveStaff.ExecuteNonQuery();
}
catch
{
//Error when save data

MessageBox.Show("Error to save on database");
openCon.Close();
Cursor = Cursors.Arrow;
}

Answer 1

You have to set Connection property of Command object and use parametersized query instead of hardcoded SQL to avoid SQL Injection.

 using(SqlConnection openCon=new SqlConnection("your_connection_String"))
    {
      string saveStaff = "INSERT into tbl_staff (staffName,userID,idDepartment) VALUES (@staffName,@userID,@idDepartment)";

      using(SqlCommand querySaveStaff = new SqlCommand(saveStaff))
       {
         querySaveStaff.Connection=openCon;
         querySaveStaff.Parameters.Add("@staffName",SqlDbType.VarChar,30).Value=name;
         .....
         openCon.Open();

         querySaveStaff.ExecuteNonQuery();
       }
     }