Esempio n. 1
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        private void button4_Click(object sender, EventArgs e)
        {
            DafestyEntities context = new DafestyEntities();

            //var q = from x in context.Customers select x;

            //Customer c = context.Customers.Where(x => x.CustomerID == "1111").First();

            //label1.Text = c.CustomerName;

            List <Customer> lst = context.Customers.Where(x => x.MemberRating == "A").ToList();

            lst = context.Customers.OrderBy(x => x.CustomerName).ToList();
            lst = context.Customers.Where(y => y.MemberRating == "A").OrderBy(x => x.CustomerName).ToList();
            lst = context.Customers.Where(y => y.MemberRating == "A" && y.CustomerName.Substring(0, 1) == "B").ToList();

            dataGridView1.DataSource = lst;

            int noofAmem = context.Customers.Count(x => x.MemberRating == "A");

            label1.Text = (noofAmem).ToString();
            decimal?d = context.Customers.Sum(x => x.AmountSpent);  // nullable datatypes

            label1.Text = (d).ToString();
        }
Esempio n. 2
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        private void button3_Click(object sender, EventArgs e)
        {
            DafestyEntities context = new DafestyEntities();

            var             q   = from x in context.Customers where x.MemberRating == "A" && x.CustomerName.Substring(0, 1) == "R" orderby x.CustomerName select x;
            List <Customer> lst = q.ToList();

            dataGridView1.DataSource = lst;
        }
Esempio n. 3
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        private void button2_Click(object sender, EventArgs e)
        {
            DafestyEntities context = new DafestyEntities();

            // write a LINQ Query (don't need to type SQL)
            var q = from x in context.Customers where x.CustomerID == "1007" select x;

            // get first object from Collection
            Customer c = q.First();

            label1.Text = c.CustomerName;
        }
Esempio n. 4
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        /// <summary>
        /// Example of LINQ Query returning only selected columns
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button5_Click(object sender, EventArgs e)
        {
            //DafestyEntities context = new DafestyEntities();
            //var q = from x in context.Customers
            //        select new { x.CustomerID, x.CustomerName, x.MemberRating }; // deriving anonymous class from the Customers class
            //var q1 = from x in context.Customers select x;
            //Customer c = q1.First();
            //dataGridView1.DataSource = q.ToList();

            DafestyEntities context = new DafestyEntities();

            var q = from x in context.Customers
                    group x by x.MemberRating into g
                    select new { MemberCategory = g.Key, AMT = g.Sum(y => y.AmountSpent) };

            dataGridView1.DataSource = q.ToList();
        }
Esempio n. 5
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        /// <summary>
        /// Example of updating, adding and inserting the DB with EF
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button2_Click(object sender, EventArgs e)
        {
            DafestyEntities ctx = new DafestyEntities();
            Customer        c   = ctx.Customers.First(x => x.CustomerID == "1007"); // Lambda expression

            label1.Text    = c.CustomerName + " " + c.MemberRating;
            c.MemberRating = "B";
            label1.Text    = c.CustomerName + " " + c.MemberRating;

            //// create a new customer
            //Customer cN = new Customer();
            //cN.CustomerID = "1007";
            //cN.CustomerName = "Bond";
            //cN.MemberRating = "Z";

            //// added to the customers collection
            //ctx.Customers.Add(cN);

            // remove from customers collection
            ctx.Customers.Remove(c);

            ctx.SaveChanges(); // save your changes
        }
Esempio n. 6
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        private void button1_Click(object sender, EventArgs e)
        {
            DafestyEntities context = new DafestyEntities();

            dataGridView1.DataSource = context.Customers.ToList();
        }