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();
}
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;
}
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;
}
/// <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();
}
/// <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
}
private void button1_Click(object sender, EventArgs e)
{
DafestyEntities context = new DafestyEntities();
dataGridView1.DataSource = context.Customers.ToList();
}
