Question

Guys I searched around like hell but nothing could help me so I think it’s time to ask. Before I write to problem, I need to say that I need it’s solution asap because it’s a project that I have to give tomorrow and I stuck on the same subject since ages and still losing time.

OK here it is;

I need to add a book to a library system, at first phase I add the standard book features which has only “one value” like (name, page number, publishing time, publisherID etc) but as wanted by me book MAY HAVE MULTIPLE WRITERS AND CATEGORIES which killed me and still I can’t resolve. I tried to add book to it’s (books) table then with the information i got from that i did an other insert op. to (bookWriters) table. While I check it, compiler does everything in order without error but when I check table from SQL Server there is nothing.

Here is what I tried to do;

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Data.SqlClient;

namespace Project_
{
    public partial class addBook: Form
    {
        public addBook()
        {
            InitializeComponent();
        }

        public main refForm;

        int chosenWritersNumber; //how many writers have selected on listbox
        int[] writers= { }; // an array list that i keep writerIDs that comes from class
        int ind = 0;

        int insertedBookID; // to catch latest added book's ID
        int chosenWriterID; // writer that will be added

        private void bookAddingPreps()
        {
            chosenWritersNumber = lstWriters.SelectedItems.Count;

            Array.Resize<int>(ref writers, chosenWritersNumber );

            for (int i = 0; i < chosenWritersNumber ; i++)
            {
                writers[i] = ((X_Writers)lstWriters.SelectedItems[i]).XWriterID;
            }
        }

        private void addMainBookInfos()
        {
            SqlConnection con = new SqlConnection(Conn.Activated);

            SqlCommand com = new SqlCommand("AddBook", con);

            com.CommandType = CommandType.StoredProcedure;

            com.Parameters.AddWithValue("@BookISBN", txtISBN.Text);            

            con.Close();
        }

        private void catchAddedBookID()
        {
            SqlConnection con = new SqlConnection(Conn.Activated);
            SqlCommand com = new SqlCommand("catchBookID", con);

            com.CommandType = CommandType.StoredProcedure;

            con.Open();
            SqlDataReader dr = com.ExecuteReader();
            if (dr.HasRows)
            {
                while (dr.Read())
                {
                    insertedBookID = dr.GetInt32(0);
                }
            }
            dr.Close();
            con.Close();
        }

        private void addWritersOfTheBook()
        {
            chosenWriterID = writers[ind];

            SqlConnection con = new SqlConnection(Conn.Activated);

            SqlCommand com = new SqlCommand("addBookWriters", con);
            com.CommandType = CommandType.StoredProcedure;

            com.Parameters.AddWithValue("@BookID", insertedBookID);
            com.Parameters.AddWithValue("@WriterID", chosenWriterID);
            con.Close();
        }

I call these methods on click of a button. You see also stored procedure names but as I checked they all correct, there must be a mistake in this page that I still cant see but if it’s needed I can add what procedures writes but they all tested and seems working.

So as i said, when i do this, as ind = 0, a writer should have been added, break point shows everything is ok and compiler doesnt show any errors but when I check sql server table, its empty.

Written in C# with using Visual Studio 2010 Ultimate and SQL Server 2008 Dev.

Thanks

Answer 1

You forget to execute your SqlCommand’s. Make a call to command.ExecuteNonReader(); to execute it without expecting any results. see: http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.aspx

Apart form that, dont forget to dispose the resources acquired in your methods. Something like:

private void addMainBookInfos() 
{ 
    using (SqlConnection con = new SqlConnection(Conn.Activated))
    using (SqlCommand com = new SqlCommand("AddBook", con))
    {
        com.CommandType = CommandType.StoredProcedure; 
        com.Parameters.AddWithValue("@BookISBN", txtISBN.Text);             

        com.ExecuteNonQuery()

        // close can be omitted since you are already using the 'using' statement which automatically closes the connection
        con.Close(); 
    }
}