This article shows transferring of data from one type of Data Source to another type of Data Source.

Aim: To add ListBox items with values from multiple tables or views.

Problem:

During my Academic Project (The Event Management System) there is a situation where I needed to display the Supplier's Names from multiple Tables (such as Caterer, Manpower, and Advertisement etc.). Right now I have completed my Academic year, but after extensive efforts and guidance from many people I succeed to achieve the intended goal in a simple manner.

Some weeks ago I placed this question in the Mind Cracker Network. Here I tried to present the sample for the same portion of the code.

This article contains the simplest way to do it.

Solution:

Requirements:
Justification:
  1. First we have to make some declarations as follows.

    SqlConnection Conn =new SqlConnection("Data Source=.\\SqlExpress; "
     + "Initial Catalog=Northwind; Integrated security=True");
    SqlDataReader rdr;
    SqlCommand cmd;

    //The target is very simple, we just have to
    //execute simple SELECT statements with Data Reader using Command Object

  2. After the declarations, execute the SELECT statement; then add each item from the Data Reader to the ListBox. To identify data from each table you can add a TABLE name as ListBox item at the beginning of the data being displayed.

    private void button1_Click(object sender, EventArgs e)
    {
    Conn.Open();

    //Supplier
     listBox1.Items.Add("-----Suppliers----");
    cmd = new SqlCommand("Select TOP(5) ContactName As PersonName from Suppliers", Conn);
    rdr = cmd.ExecuteReader();

    while (rdr.Read())
    {
    listBox1.Items.Add(rdr.GetValue(0).ToString());
    }
    rdr.Close();

    //Customers
     listBox1.Items.Add("-----Customers----");
    cmd = new SqlCommand("Select TOP(5) ContactName As PersonName from Customers", Conn);
    rdr = cmd.ExecuteReader();

    while (rdr.Read())
    {
    listBox1.Items.Add(rdr.GetValue(0).ToString());
    }
    rdr.Close();

    .
    .
    .
    .
    .
    }

  3. Figure 1 shows the intended result:

    ListBox.gif

    Figure 1

Summary:

In this article, we have seen the ListBox operation with multiple data sources in C# Programming.