private static void DeleteRandomContact(ContactsContext context)
{
Random random = new Random();
var randomContact = context.Contacts.OrderBy(p => p.ContactId).Skip(random.Next(context.Contacts.Count())).First();
randomContact.EmailAddresses.Clear();
randomContact.Addresses.Clear();
randomContact.PhoneNumbers.Clear();
context.Contacts.Remove(randomContact);
context.SaveChanges();
}
private static void InsertRandomContact(ContactsContext context)
{
// a little bit of helper stuff
string[] firstNames = { "Kevin", "Rich", "Eve", "Leanne", "Chris" };
string[] lastNames = { "Griffin", "Dudley", "Turzillo", "Lappe", "Bannon" };
Random randomNumber = new Random();
// create a new contact
Contact newContact = new Contact()
{
FirstName = firstNames[randomNumber.Next(firstNames.Count())],
LastName = lastNames[randomNumber.Next(lastNames.Count())],
EmailAddresses = new List<EmailAddress>(new EntityCollection<EmailAddress>()),
Addresses = new List<Address>(new EntityCollection<Address>()),
PhoneNumbers = new List<PhoneNumber>(new EntityCollection<PhoneNumber>())
};
// add a couple email addresses
newContact.EmailAddresses.Add(new EmailAddress()
{
Email =
string.Format("{0}.{1}@gmail.com", newContact.FirstName,
newContact.LastName)
});
newContact.EmailAddresses.Add(new EmailAddress()
{
Email =
string.Format("{0}.{1}@yahoo.com", newContact.FirstName,
newContact.LastName)
});
// add a couple phone numbers
for (int x = 0; x < randomNumber.Next(1, 5); x++)
{
newContact.PhoneNumbers.Add(new PhoneNumber()
{
Number =
string.Format("555-{0:000}-{1:0000}", randomNumber.Next(0, 999),
randomNumber.Next(0, 9999))
});
}
// add contact
context.Contacts.Add(newContact);
context.SaveChanges();
}
private static void Cleanup(ContactsContext context)
{
var contactList = context.Contacts.ToList();
foreach (var contact in contactList)
{
// delete emails
contact.EmailAddresses.Clear();
// delete phone numbers
contact.PhoneNumbers.Clear();
// delete address
contact.Addresses.Clear();
// delete contact
context.Contacts.Remove(contact);
}
context.SaveChanges();
}
static void Main(string[] args)
{
Console.WriteLine("Back to Basics: Entity Framework");
Console.WriteLine("Code First Demo");
Console.WriteLine();
/*
* Load an instance of the context
*/
var context = new ContactsContext();
Cleanup(context);
/*
* Select all the contacts
*/
SelectAllContacts(context);
Console.WriteLine();
/*
* Insert a new contact
*/
for (int x = 0; x < 10; x++)
InsertRandomContact(context);
Console.WriteLine();
/*
* Select all the contacts AGAIN
*/
SelectAllContacts(context);
Console.WriteLine();
/*
* Update a (random) contact
*/
UpdateContacts(context);
Console.WriteLine();
/*
* Select all the contacts A THIRD TIME
*/
SelectAllContacts(context);
Console.WriteLine();
/*
* Delete a contact
*/
DeleteRandomContact(context);
Console.WriteLine();
/*
* Select all the contacts ONE LAST TIME!
*/
SelectAllContacts(context);
Console.WriteLine();
}
private static void UpdateContacts(ContactsContext context)
{
var contacts = context.Contacts.ToList();
foreach (var contact in contacts)
{
// we're going to swap all the first names with last names
var firstName = contact.FirstName;
var lastName = contact.LastName;
contact.FirstName = lastName;
contact.LastName = firstName;
// we're now going to delete a phone number and email address
if (contact.PhoneNumbers.Any())
contact.PhoneNumbers.Remove(contact.PhoneNumbers.First());
if (contact.EmailAddresses.Any())
contact.EmailAddresses.Remove(contact.EmailAddresses.First());
context.SaveChanges();
}
}
private static void SelectAllContacts(ContactsContext context)
{
if (context.Contacts.Any())
{
foreach (var contact in context.Contacts)
{
Console.WriteLine(
string.Format("I see {0} {1}. They have {2} phone numbers and {3} email addresses.",
contact.FirstName, contact.LastName, contact.PhoneNumbers.Count(),
contact.EmailAddresses.Count()));
}
}
else
{
Console.WriteLine("No contacts where found!");
}
}