Entity Framework change tracking is often something that doesn't require too much thought from the app developer. However, change tracking and the DetectChanges method are a part of the stack where there is a tension between ease-of-use and performance. For this reason it can be useful to have an idea of what is actually going on such you can make an informed decision on what to do if the default behavior is not right for your app.
Part 1: What does DetectChanges do?
http://blog.oneunicorn.com/2012/03/10/secrets-of-detectchanges-part-1-what-does-detectchanges-do/
Part 2: When is DetectChanges called automatically?
http://blog.oneunicorn.com/2012/03/11/secrets-of-detectchanges-part-2-when-is-detectchanges-called-automatically/
Part 3: Switching off automatic DetectChanges
http://blog.oneunicorn.com/2012/03/12/secrets-of-detectchanges-part-3-switching-off-automatic-detectchanges/
Part 4: Binary properties and complex types
http://blog.oneunicorn.com/2012/03/13/secrets-of-detectchanges-part-4-binary-properties-and-complex-types/
If the relationship is required (the FK doesn't allow NULL values) and the relationship is not identifying (which means that the foreign key is not part of the child's (composite) primary key) you have to either add the child to another parent or you have to explicitly delete the child (with DeleteObject then). If you don't do any of these a referential constraint is violated and EF will throw an exception when you call SaveChanges - the infamous "The relationship could not be changed because one or more of the foreign-key properties is non-nullable" exception or similar.
Great sources to get started and to look back at. Covers everything from scaffolding to ef concurrency management.
Getting Started with ASP.NET MVC 5
Getting Started with Entity Framework 6 Code First using MVC 5
Great articles by Ben Thompson at Stratechery
var json = elasticClient.RequestResponseSerializer.SerializeToString(request);Great for debugging and finding out what json you are sending.
class MyData
{
public string name {get;set;}
}
// Sender
[FunctionName("Send")]
public static void Send(..., [ServiceBus("%Topic%")] out BrokeredMessage brokeredMessage, ...)
{
...
MyData myData = new MyData();
string bodyJson = JsonConvert.SerializeObject(myData);
brokeredMessage = new BrokeredMessage(bodyJson);
brokeredMessage.Label = "My routing info";
...
}
// Receiver
[FunctionName("Receive")]
public static void Receive([ServiceBusTrigger("%Topic%", "%Subscription%")] BrokeredMessage brokeredMessage, ...)
{
...
string bodyJson = brokeredMessage.GetBody<string>();
MyData myData = JsonConvert.DeserializeObject<MyData>(bodyJson);
...
}
If you got a DTO and want camelCase json when returning data.
Is there a way to alias response model properties in ASP.Net Web API
Observables does not update values
AJAX requests not executing or updating in Internet Explorer? Here's a solution
//Function Declaration
function add(a,b) {return a + b};
//Function Expression
var add = function(a,b) {return a + b};
CommandQuerySeparation (Martin Fowler)
http://martinfowler.com/bliki/CommandQuerySeparation.html
CQRS (Martin Fowler)
http://martinfowler.com/bliki/CQRS.html
CQRS, Task Based UIs, Event Sourcing agh!
http://codebetter.com/gregyoung/2010/02/16/cqrs-task-based-uis-event-sourcing-agh/
Reference 1: CQRS in Context
http://msdn.microsoft.com/en-us/library/jj591560
Reference 2: Introducing the Command Query Responsibility Segregation Pattern
http://msdn.microsoft.com/en-us/library/jj591573
Reference 3: Introducing Event Sourcing
http://msdn.microsoft.com/en-us/library/jj591559
Reference 4: A CQRS and ES Deep Dive
http://msdn.microsoft.com/en-us/library/jj591577
CQRS Journey
http://msdn.microsoft.com/en-us/library/jj554200.aspx
Command and Query Responsibility Segregation (CQRS) Pattern
http://msdn.microsoft.com/en-us/library/dn568103.aspx
Event Sourcing Pattern
http://msdn.microsoft.com/en-us/library/dn589792.aspx
CRUD, Only When You Can Afford It
http://msdn.microsoft.com/en-us/library/ms978509.aspx
Stereotypical Architecture
https://cqrs.wordpress.com/documents/a-stereotypical-architecture/
CQRS Introduction
https://cqrs.wordpress.com/documents/cqrs-introduction/
CQRS and Event Sourcing
https://cqrs.wordpress.com/documents/cqrs-and-event-sourcing-synergy/
Task-Based UI
https://cqrs.wordpress.com/documents/task-based-ui/
http://cqrs.nu/tutorial/cs/01-design http://cqrs.nu/tutorial/cs/02-domain-logic http://cqrs.nu/tutorial/cs/03-read-models http://cqrs.nu/tutorial/cs/04-web-app-integration http://cqrs.nu/tutorial/cs/05-other-matters
On Wednesday, September 3, 1997 9:00:00 AM UTC+2, Andreas Nilsson wrote:
I'm currently porting an Motif application that have been runnning on
SunOS 4.1.1 (X11R4 and unknown Motif version) to Solaris 2.5.1 (X11R5
and Motif 1.2).
On SunOS all the windows default size were correct, i.e. all the
buttons, scollbars etc fitted nicely in the windows as they were
created. On Solaris the windows
are created in minimum size by default (so you can't see whats in them).
The typical window is constructed of a form widget in a dialogshell
widget. Of course
the form widget then includes subwidgets in the form of buttons and
scollbars.
As far as I can see all the widgets are created and managed in the
correct order.
It is not an acceptable solution to set default width and height on
every window in the application.
Anyone got a clue about what I'm doing wrong ??
Thanks in advance
Andreas
--
-----------------------------------------------------
Andreas Nilsson E-mail: and...@basesoft.se
Basesoft Open Systems Voice: +46 (0)8 13 17 20
P.O. Box 34 140 Fax: +46 (0)8 13 17 25
S-100 26 Stockholm
Sweden
-----------------------------------------------------
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer]
"AltTabSettings"=dword:00000001
Thanks to Scott Weinstein
label => 'collection',
type => 'Select',
name => 'collection_id',
options => [ map { [ $_->id, $_->collection . ' - ' . $_->product->product ] }
$c->model('PB::Collections')->search( {}, {order_by => 'product.product, collection', prefetch => 'product'} )->all() ],
constraints => [ 'Required' ],
},
label => 'items',
type => 'Select',
name => 'items',
db => {
model => 'PB::Items',
label_column => 'description',
m_to_m_column => 'item_id',
attributes => { prefetch => [ {book => 'title' }, {book => 'collection' }, {book => 'format' } ] , order_by => 'title.title, collection.collection, format.format ' },
},
multiple => 1,
size => 20,
},
And the following sub has to be added to the items resultset:
sub description {
$_[0]->book->title->title . ' - ' . $_[0]->book->collection->collection . ' - ' . $_[0]->book->format->format . ' - ' . $_[0]->isbn;
}
% DBIC_TRACE=1 my_programme.plDBIC_TRACE="1=/tmp/sql.debug"SELECT bindings.*, COALESCE( ft.binding, bindings.binding ) AS sortable_binding
FROM bindings
LEFT OUTER JOIN ( SELECT binding, binding_id FROM bindings_translated WHERE language = ? ) AS ft ON ( ft.binding_id = bindings.id ) $c->stash->{collections} = [ $product->collections( { language => $c->stash->{language} }, { '+select' => \'COALESCE(translations.collection, me.collection) AS translated_collection', join => [ 'translations' ], order_by => [ 'translated_collection' ], } )->all() ];
"Content-Type: text/plain; charset=utf-8"
Weezer's latest single is quite good. And fun. Sorry to say the Red Album isn't as good as the exceptional Pinkerton and Blue Album. But Weezer always rocks!
