Add to Favorites button in ASP.Net GridView

1. Add a Button in each Row for GridView

2. In the command argument of the button set the Id of the Item

3. Create a Table called Favorites where you will have 2 fields UserId and ItemId

4. On the click event of Button get the ItemId as following

    protected void Button1_Click(object sender, EventArgs e)
    {
        string itemId = (sender as Button).CommandArgument;

        //Insert to database here
    }