LINQ Learning.com

LINQ to Entities


LINQ to Entities provides Language-Integrated Query (LINQ) support that enables
developers to write queries against the Entity Framework conceptual model using
Visual Basic or Visual C#.


 



LINQ to Entities



I recently received an email
asking about LINQ to Entities.  Earlier in the developmental stage of LINQ and
my book, it became clear that LINQ to Entities was outside the umbrella of core
LINQ.


 


Tutorial:

Getting started with Linq-To-Entities


In my humble opinion, Linq is easily the greatest thing .Net has come out with
in the past few years, and along with it, Linq-to-SQL (L2S) was a godsend.


 



LINQ to Entities, what is not supported?



Recently and after .Net 3.5 SP1 & Visual Studio.Net 2008 SP1 released, I started
to play with LINQ to Entities. Really Entity Framework is interesting. Maybe not
the best ORM tool, but still it is interesting and easy to use plus it is all
one IDE at the end.


 



LINQ-to-Entities: The Blackberry Storm of ORMs?


...So enter LINQ-to-Entities – the ADO.NET team’s “answer” to LINQ-to-SQL.
Unfortunately, while LINQ-to-SQL was a wonderful, polished jewel of
functionality that was a nice example of IJW (“it just worked”),
LINQ-to-Entities seems to be a product of Architecture Astronauts who would
rather bamboozle us with their cleverness than actually provide useful
solutions.


 



Left Outer Join in LINQ to Entities (for Entity Framework 4)


In this post we will explore the most practical ways of performing left outer
joins in LINQ to Entities. The same principles applying to LINQ to Entities for
EF 4 also apply to LINQ2SQL.



 



LINQ To Entities, SQL and performance


In this posting I will show you some LINQ To Entities queries and SQL that is
generated for them. I added also some thoughts about performance.


 



Getting LINQ to SQL and LINQ to Entities to use NOLOCK


I was visiting a local company where a bunch of friends work and they asked how
to get LINQ to SQL to use NOLOCK. They were explicitly asking
how to get the SQL generated by LINQ to SQL to add the NOLOCK hints to the end.



 



LINQ Learning Guide: LINQ to Entities


LINQ Quick Start



LINQ and Visual Studio 2008's new language features



LINQ Providers


 



Linq-to-SQL vs Linq-to-Entities : Revisited


After 2 months of nothing but L2E, I feel I can give a decent comparison.


 


WHERE IN()-style Queries in LINQ to Entities


LINQ to Entities doesn’t contain a definition for Contains(), so you have a
couple of options where you want to write a LINQ query which operates like a
WHERE IN() clause in SQL.



 



LINQ to Entities – Join Queries


This is my first project on LINQ, and I got surprised on how tuff it is to build
join queries. But the trick is to understand how the LINQ to Entities work.


I will discuss in this blog some of the complicated queries that I built and how
I built them.


 



LINQ to Entities n-tier disconnected CRUD


It seems so easy to add, update and delete objects in LINQ to SQL, but in LINQ
to Entities, unless I’m missing something, the coder is expected to retrieve an
object before modifying it or deleting it.


 


LINQ to
Entities


With LINQ to Entities, we can leverage object inheritance and data complexity.
For instance, we can have a complex Customer type that includes its Orders as a
sequence property, inheriting its base structure from the Contact type. From an
entity point of view, we do not care how the Contact, Customer, and Orders of
the Customer are brought to us; we care about them only when they are in memory.


 


LINQ to Entities


Query language over ADO.NET Entities. At the moment the ADO.NET Entity Framework
seems to have a parallel effort with the LINQ to SQL project. For example, they
both have generators for building object models for relational databases. How
these overlaps will be resolved is an emerging topic.


 




LINQ to Entities - The ObjectContext


ADO.NET V3.0 will come with the ADO.NET Entity
Framework and a flexible object relational mapping layer that plugs in to LINQ -
LINQ to Entities. In this video we'll take a look at one of the key types in the
object model, the ObjectContext that encapsulates a connection to our model, the
metadata of the model, the ability to perform CRUD operations and state
management capabilities.


 



LINQ to Entities, Workarounds on what is not supported



Here I am going to provide workarounds these things. First one will be wrapping
the entities with Business Classes. And the second way will be using client
evaluation which is converting to work with LINQ to Object. Before you go
further, I recommend that you read my previous post to save your time.


 


Dynamic LINQ to Entities
Queries Using WCF/WPF Demo Code


It has been a while since I have undertaken a large article, so I thought it was
about time I corrected that, and wrote a fairly meaty article. This article
represents this meat.


 


LINQ to
Entities: Basic Concepts and Features


In my first three articles on CodeProject.com, I have explained the fundamentals
of Windows Communication Foundation (WCF)


 



LINQ-to-Entities: Follow-Up


There’s been a bit of discussion about my last article, “LINQ-to-Entities: The
Blackberry Storm of ORMs?“. I thought I’d try to clear up a bit of what I was
trying to say, especially with regards my statement about LINQ-to-Entities
returning differing values depending on code order.


 


LINQ
to Entities


…  been investigating LINQ to Entities lately, and I have
to tell you, it looks great! I saw a presentation by Adam Cogan
and Justin King.


 



LINQ to Entities n-tier disconnected CRUD


... seems so easy to add, update and delete objects in LINQ
to SQL, but in LINQ to Entities, unless I'm
missing something, the coder is expected to …


 



WCF 4.0 Multi-tier Services Development with LINQ to Entities




…  hands-on guide updated for VS2010 Master WCF and LINQ to
Entities concepts by completing practical examples and applying them to
your real-world assignments The first and only book to combine
WCF and …


 



LINQ to SQL or LINQ to Entities?


…  mail lists there was a question raised about whether LINQ to
SQL would support LINQ to Oracle. There was some discussion
over if a direct use would work, passing …


 



And now on to LINQ to Entities


…  way too much work with PLINQO and LINQ to SQL, I discovered
that it simply won't work for my little project.  The problem is that I want
to use single table inheritance for some common elements
(notes, addresses, etc.); however, I want to be able to
access the children of an item as a collection.  For example, …


 



Linq-to-SQL, Linq-to-DataSet and Linq-to-Entities


…  to SQL is an O/RM (object relational mapping) implementation
that was provided …  (.NET Framework version 3.5) release. It allows us
to model a relational database using .NET classes and query those
models using …


 



C# Entity Framework & Linq to Entities (Quick Reference)


…  Entity Framework & Linq to Entities: CRUD (Create, Read,
Update, Delete) Tasks with CSharp The Entity Framework in conjunction with Linq
to Entities seems to be Microsoft’s ORM
(Object Relational Mapping) flavor of the moment.



 



Linq to Entities–Performance during search operation


…  There are a lot of posts on net regarding this subject and to
be honest you can conclude that the performance of Linq to
Entities is poor. I did perform some tests my self and here are some …


 



LINQ to Entities at a (slightly long) glance


…  I can come back whenever for a quick recap of basic LINQ to
Entities concepts. It's a compression of chapter 4 from Julie …  purposes. Seek
out further resources and spend more time to master the topic.
Projections and ToString() Consider overriding …


 



"LINQ to Entities" and "ADO.NET Entity Framework"


…  you are interested in the Entity Data Model and want to
know more about Microsoft's Data Access strategy in Orcas and .NET …  by our
data access team over the weekend.  "LINQ to Entities" will
supplement other LINQ extensions like "LINQ to …


 


LINQ to
Entities blog posts


Discussions about entities linq


 



Linq to Entity with multiple left outer joins



Linq to Entities - Delete from a link / junction table



Linq to Entities, random order


Linq to Entities. XML


 


ADO.NET Entity
Framework


ADO.NET Entity Framework abstracts the relational (logical) schema of the data
that is stored in a database and presents its conceptual schema to the
application. At development time, this abstraction eliminates the
object-relational impedance mismatch that is otherwise common in conventional
database-oriented programs. The run-time overhead of mapping between the
conceptual schema and the underlying relational schema is still a factor to be
considered.


 


The
ADO.NET Entity Framework Overview


Eliminate the impedance mismatch between data models and between languages that
application developers would otherwise have to deal with new features available
in the upcoming version of ADO.NET...  Despite the great advancements in
integration of databases and development environments, there is still an
impedance mismatch between the two that's not easily solved by just enhancing
the libraries and APIs used for data programming.