private static void Joins()
{
using (var context = new SampleEntities())
{
var joinQuery = from c in context.Contacts
join oa in context.vOfficeAddresses on c.ContactID equals oa.ContactID
select new
{
oa.FirstName,
oa.LastName,
c.Title,
oa.Street1,
oa.City,
oa.StateProvince
};
var nestedQuery = context.vOfficeAddresses.Select(oa => new
{
oa.FirstName,
oa.LastName,
Title = context.Contacts.Where(c => c.ContactID == oa.ContactID).Select(c => c.Title).FirstOrDefault(),
oa.Street1,
oa.City,
oa.StateProvince
});
}
}
private static void Edit()
{
using (var context = new SampleEntities())
{
var contact = context.Contacts.First();
contact.FirstName = "Julia";
contact.ModifiedDate = DateTime.Now;
context.SaveChanges();
}
}
private static void QueryContacts()
{
using (var context = new SampleEntities())
{
var contacts = context.Contacts;
foreach (var contact in contacts)
{
Console.WriteLine("{0} {1}", contact.FirstName.Trim(), contact.LastName);
}
}
}
private static void VariousMethods()
{
using (var context = new SampleEntities())
{
var contacts = context.Contacts.Where(c => c.FirstName == "Robert");
var list = contacts.ToList();
Console.WriteLine(contacts.ToString());
Console.ReadLine();
}
}
private static void QueryLambda()
{
var context = new SampleEntities();
var contacts = context.Contacts
.Where(c => c.FirstName == "Robert");
foreach (var contact in contacts)
{
Console.WriteLine("{0} {1}", contact.FirstName.Trim(), contact.LastName);
}
}
private static void Grouping()
{
using (var context = new SampleEntities())
{
var groupQuery = from c in context.Contacts
group c by c.Title
into myGroup
orderby myGroup.Key
select new { MyTitle = myGroup.Key, MyGroup = myGroup };
}
}
private static void QueryLINQ()
{
var context = new SampleEntities();
var contacts = from c in context.Contacts
where c.FirstName == "Robert"
select c;
foreach (var contact in contacts)
{
Console.WriteLine("{0} {1}", contact.FirstName.Trim(), contact.LastName);
}
}
private static void QueryContactsLambda()
{
using (var context = new SampleEntities())
{
var contacts = context.Contacts.Where(c => c.FirstName == "Robert").OrderBy(foo => foo.LastName);
foreach (var contact in contacts)
{
Console.WriteLine($"{contact.FirstName.Trim()} {contact.LastName}");
}
Console.WriteLine("Perss Enter...");
Console.ReadLine();
}
}
private static void QueryContacts()
{
using (var context = new SampleEntities())
{
var contacts = context.Contacts;
foreach (var contact in contacts)
{
Console.WriteLine($"{contact.FirstName.Trim()} {contact.LastName}");
}
Console.WriteLine("Perss Enter...");
Console.ReadLine();
}
}
private static void ExecuteOption()
{
using (var context = new SampleEntities())
{
var list = context.ContactsObjectSet.Execute(MergeOption.NoTracking).ToList();
foreach (var address in list)
{
Console.WriteLine(address.FirstName);
}
Console.ReadLine();
}
}
private static void LinqProjections()
{
using (var context = new SampleEntities())
{
var contacts = context.Contacts.Where(c => c.FirstName == "Robert").OrderBy(foo => foo.LastName).Select(c => new { c.Title, c.FirstName, c.LastName });
foreach (var contact in contacts)
{
Console.WriteLine($"{contact.FirstName.Trim()} {contact.LastName}");
}
Console.WriteLine("Perss Enter...");
Console.ReadLine();
}
}
private static void EagerLoading()
{
using (var context = new SampleEntities())
{
var contacts = context.Contacts.Include(a => a.Addresses).Select(c => c).ToList();
foreach (var contact in contacts)
{
Console.WriteLine($"{contact.FirstName.Trim()} {contact.LastName} {contact.Addresses.Count}");
}
Console.WriteLine("Perss Enter from eager...");
Console.ReadLine();
}
}
private static void QueryEntityQuery()
{
var context = new SampleEntities();
var query = "SELECT VALUE c " +
"FROM SampleEntities.Contacts AS c " +
"WHERE c.FirstName = 'Robert'";
ObjectQuery <Contact> contacts = context.CreateQuery <Contact>(query);
foreach (var contact in contacts)
{
Console.WriteLine("{0} {1}", contact.FirstName.Trim(), contact.LastName);
}
}
private static void RemoveEnitiy()
{
using (var context = new SampleEntities())
{
var contact = context.Contacts.Find(438);
if (contact != null)
{
context.Contacts.Remove(contact);
}
context.SaveChanges();
}
}
private static void QueryContacts()
{
using (var context = new SampleEntities())
{
var contacts = from c in context.Contacts select c;
foreach (var contact in contacts)
{
Console.WriteLine(contact.FirstName + " " + contact.LastName);
}
Console.Read();
}
}
private static void ChainingAggregates()
{
using (var context = new SampleEntities())
{
var chainingAggregatesQuery =
context.Contacts.GroupBy(c => c.Title).OrderBy(myGroup => myGroup.Key).Select(myGroup => new
{
MyTitle = myGroup.Key,
MyGroup = myGroup,
Max = myGroup.Max(c => c.AddDate),
Count = myGroup.Count()
});
}
}
private static void QueryContactsLinq()
{
using (var context = new SampleEntities())
{
var contacts = from c in context.Contacts
where c.FirstName == "Robert"
select c;
foreach (var contact in contacts)
{
Console.WriteLine($"{contact.FirstName.Trim()} {contact.LastName}");
}
Console.WriteLine("Perss Enter...");
Console.ReadLine();
}
}
private static void CreateParentChildEntity()
{
using (var context = new SampleEntities())
{
var contact = new Contact
{
FirstName = "Camey",
LastName = "Combs",
AddDate = DateTime.Now,
ModifiedDate = DateTime.Now,
Addresses = new List <Address>()
};
var address = new Address
{
Street1 = "One Main Street",
City = "Olympia",
StateProvince = "WA",
AddressType = "Business",
ModifiedDate = DateTime.Now,
Contact = contact
};
var contact1 = new Contact
{
FirstName = "Camey",
LastName = "Combs",
AddDate = DateTime.Now,
ModifiedDate = DateTime.Now,
Addresses = new List <Address> {
new Address
{
Street1 = "One Main Street",
City = "Olympia",
StateProvince = "WA",
AddressType = "Business",
ModifiedDate = DateTime.Now
}
}
};
context.Contacts.Add(contact1);
contact.Addresses.Add(address);
//join the new address to the contact
//add the new graph to the context
context.Contacts.Add(contact);
context.SaveChanges();
}
}
private static void QueryContacts()
{
using (var context = new SampleEntities())
{
IQueryable <Contact> contacts = context.Contacts.Where(a => a.LastName.StartsWith("A"));
if (!Object.ReferenceEquals(contacts, null))
{
foreach (var contact in contacts)
{
Console.WriteLine("{0} {1}", contact.FirstName.Trim(), contact.LastName);
}
}
}
Console.ReadLine();
}
private static void MergeOptionExampleObjectSet()
{
using (var context = new SampleEntities())
{
var contactsQuery = context.ContactsObjectSet.Where(c => c.FirstName == "Robert");
((ObjectQuery)contactsQuery).MergeOption = MergeOption.PreserveChanges;
var results = contactsQuery.ToList();
foreach (var address in results)
{
Console.WriteLine(address.FirstName);
}
Console.ReadLine();
}
}
private static void MergeOptionExample()
{
using (var context = new SampleEntities())
{
var ctx = ((IObjectContextAdapter)context).ObjectContext.CreateObjectSet <Contact>();
var contactsQuery = ctx.Select(m => m);
((ObjectQuery)contactsQuery).MergeOption = MergeOption.NoTracking;
var list = contactsQuery.ToList();
foreach (var address in list)
{
Console.WriteLine(address.FirstName);
}
Console.ReadLine();
}
}
private static void CreateEntity()
{
using (var context = new SampleEntities())
{
var contact = context.Contacts.First(c => c.FirstName == "Robert");
var address = new Address
{
Street1 = "One Main Street",
City = "Burlington",
StateProvince = "VT",
AddressType = "Business",
ModifiedDate = DateTime.Now,
Contact = contact
};
contact.Addresses.Add(address);
//join the new address to the contact
context.SaveChanges();
}
}
private static void LetProjectionWithLinq()
{
using (var context = new SampleEntities())
{
var contacts = from c in context.Contacts
where c.FirstName == "Robert"
let contactName = new { c.Title, c.LastName, c.FirstName }
select contactName;
foreach (var contact in contacts)
{
Console.WriteLine($"{contact.FirstName.Trim()} {contact.LastName}");
}
var contacts1 =
from c in context.Contacts
where c.FirstName == "Robert"
let foo = new
{
ContactName = new { c.Title, c.LastName, c.FirstName },
c.Addresses //this participates in change tracking and DB updates
}
orderby foo.ContactName.LastName
select foo;
foreach (var contact in contacts1)
{
var name = contact.ContactName;
Console.WriteLine(
$"{name.Title.Trim()} {name.FirstName.Trim()} {name.LastName.Trim()}: # Addresses {contact.Addresses.Count}");
}
var addresses = context.Addresses.Where(a => a.CountryRegion == "UK").Select(a => new
{
a,
a.Contact.FirstName,
a.Contact.LastName
});
foreach (var address in addresses)
{
Console.WriteLine($"{address.FirstName} {address.LastName} {address.a.Street1} {address.a.City}");
}
var shapedResults = from c in context.Contacts
select new
{
c.FirstName,
c.LastName,
StreetsCities = from a in c.Addresses
select new { a.Street1, a.City }
};
var shapedResultsLinq = context.Contacts.Select(c => new
{
c.FirstName,
c.LastName,
StreetsCities = c.Addresses.Select(a => new { a.Street1, a.City })
});
var flattenedResults =
from a in context.Addresses
orderby a.Contact.LastName
select new { a.Contact.LastName, a.Contact.FirstName, a.Street1, a.City };
Console.WriteLine("Perss Enter...");
Console.ReadLine();
}
}
