LINQ: Building an IQueryable Provider - Part I

Noticias externas — Mon, 30 Jul 2007 23:56:47 GMT

I’ve been meaning for a while to start up a series of posts that covers building LINQ providers using

re: LINQ: Building an IQueryable Provider - Part I

Roger Jennings — Tue, 31 Jul 2007 01:54:56 GMT

Here's an anthology of VS 2008 Beta 2's changes to LINQ and its domain-specific implementations, which includes a brief description and link to this post: http://oakleafblog.blogspot.com/2007/07/linq-changes-from-orcas-beta-1-to-vs.html

--rj

LINQ: Building an IQueryable Provider - Part I

Roller — Tue, 31 Jul 2007 02:19:06 GMT

I’ve been meaning for a while to start up a series of posts that covers building LINQ providers using

re: LINQ: Building an IQueryable Provider - Part I

Frans Bouma — Tue, 31 Jul 2007 11:17:53 GMT

Is there a reason why the scalar query isn't executed 'deferred' ? I more and more start to dislike the whole 'query is executed when you enumerate' model, as it's obscure and unclear, like with this scalar query which is executed immediately. It should have been better if there was some kind of 'execute' method on a queryable. Yes, that would require a method call, but it would make everything clear and unobscure.

I also wonder a bit if this whole 'enumeration should execute the query' drove this design. The reason is that it doesn't make any sense to have the provider on the queryable, unless execution is performed on the queryable by enumeration. If this would have been separated, you would be able to create a queryable, and pass it to a provider of choice. That's now not possible.

re: LINQ: Building an IQueryable Provider - Part I

mattwar — Tue, 31 Jul 2007 18:48:35 GMT

Frans,

The reason that scalar queries are not deferred is that they are typed as a scalar. The only representation of a deferred item we have is via IEnumerable. So if the query does not result in an IEnumerable we have no way to defer it.

The reason there is no Execute method on an IQuerayble was due to wanting the usage experience with IQueryable to be the same as IEnumerable.

The reason the provider is part of the IQueryable is so the root of the query can determine which query processor is used; so it can just be enumerated and the right thing happens. Without this you would have to keep around knowledge about which provider should execute which query and you would lose the ability to just tack on a filter operation (or skip & take) w/o needing to know the kind of query you are dealing with.

re: LINQ: Building an IQueryable Provider - Part I

Frans Bouma — Tue, 31 Jul 2007 19:28:13 GMT

Well, the reason I asked about why the provider is part of the queryable is that I now can't have general code which works on a general set of entities and write a query there and use it on any of the providers I have available, i.e. one per database: I now have to provide this info to the datasource I'm using in the code which formulates the query.

Sure, if I have just one provider, no problem. If I have generic code which can target sqlserver and oracle and db2 at the same time, I have a problem, as the code in my application should be generic (I now can do that) without knowledge of db's but when I have different providers, I can't because I have to pass these on in the code which formulates the query. So this then requires a query provider which is actually a placeholder which gets the real provider plugged in when the actual db to target is selected.

or I'm missing something obvious :)

re: LINQ: Building an IQueryable Provider - Part I

mattwar — Tue, 31 Jul 2007 19:46:20 GMT

Frans, you may be confusing the concept of a LINQ provider with an ADO database provider. You can certainly have your 'provider' target a variety of different databases, etc.

Also, tying the IQueryable provider to the IQueryable only influences the default translation of the query. You can also get the Expression from any IQueryable and attempt to process it using another provider.

LINQ: Building an IQueryable Provider - Part II

The Wayward WebLog — Tue, 31 Jul 2007 20:02:03 GMT

Now, that I’ve laid the groundwork defining a reusable version of IQueryable and IQueryProvider, namely Query and QueryProvider, I’m going to build a provider that actually does something. As I said before, what a query provider really does is execute

re: LINQ: Building an IQueryable Provider - Part I

Frans Bouma — Tue, 31 Jul 2007 22:20:05 GMT

Thanks Matt for clearing that up. I indeed am confusing the two, so if I can have a normal provider which can later on be tied to an ado.net db provider, I'm OK :)

re: LINQ: Building an IQueryable Provider - Part I

Frans Bouma — Tue, 31 Jul 2007 22:20:55 GMT

Additionally, I'm really happy you're writing these articles. I was a little disappointed when I saw that the docs to write a linq provider weren't included in orcas beta 2's docs but luckily these articles will help me get started :)

LINQ: Building an IQueryable Provider - Part III

The Wayward WebLog — Thu, 02 Aug 2007 00:13:56 GMT

Part III? Wasn’t I done in the last post? Didn’t I have the provider actually working, translating, executing and returning a sequence of objects? Sure, that’s true, but only just so. The provider I built was really fragile. It only understood one major

LINQ: Building an IQueryable Provider - Part IV

The Wayward WebLog — Thu, 02 Aug 2007 23:27:16 GMT

I just could not leave well enough alone. I had the crude LINQ provider working with just a translation of the Where method into SQL. I could execute the query and convert the results into my objects. But that’s not good enough for me, and I know it’s

How-To: Create your own provider

Roller — Fri, 03 Aug 2007 01:11:57 GMT

Links to articles detailing how to create IQueryable providers: Matt Warren: http://blogs.msdn.com/mattwar/archive/2007/07/30/linq-building-an-iqueryable-provider-part-i.aspx

LINQ: Building an IQueryable Provider - Part V

The Wayward WebLog — Sat, 04 Aug 2007 01:55:53 GMT

Over the past four parts of this series I have constructed a working LINQ IQueryable provider that targets ADO and SQL and has so far been able to translate both Queryable.Where and Queryable.Select standard query operators. Yet, as big of an accomplishment

Créer provider Linq expliqué de A à Z

Wed, 08 Aug 2007 10:53:26 GMT

Matt Warren présente sur un blog une implémentation d'un provider Linq vers SQL en plusieurs étapes.

Por fin, cómo hacer un proveedor LINQ basado en IQueryable

Sobre C#, LINQ y algo más... — Thu, 09 Aug 2007 23:11:21 GMT

Después de que muchos (un servidor incluido) se hayan roto literalmente la cabeza durante meses investigando

LINQ: Building an IQueryable Provider - Part VI

The Wayward WebLog — Fri, 10 Aug 2007 01:59:07 GMT

This is the sixth in a series of posts on how to build a LINQ IQueryable provider. If you have not read

Risorse su Linq to SQL

jankyBlog — Mon, 27 Aug 2007 10:58:32 GMT

Risorse su Linq to SQL

Want to learn LINQ? Learn some of the new language features first - it will pay off.

MSDN Ireland Blog — Tue, 28 Aug 2007 17:09:37 GMT

As you can probably tell from the title of my last few posts I've been doing some work with LINQ over

Want to learn LINQ? Learn some of the new language features first - it will pay off.

Ronan Geraghty's Weblog — Tue, 28 Aug 2007 17:09:41 GMT

As you can probably tell from the title of my last few posts I've been doing some work with LINQ over

Rolling your own LINQ Provider

Darth Bundy — Tue, 28 Aug 2007 17:33:57 GMT

I recently spend a few (many) hours doing some research into the workings of LINQ providers for an internal

Want to learn LINQ? Learn some of the new language features first - it will pay off.

.: Stefan Gabriel Georgescu's blog :. — Mon, 03 Sep 2007 17:47:19 GMT

As you can probably tell from the title of my last few posts I've been doing some work with LINQ over

LINQ: Building an IQueryable provider - Part VII

The Wayward WebLog — Wed, 05 Sep 2007 03:00:14 GMT

This is the seventh in a series of posts on how to build a LINQ IQueryable provider. If you have not

LINQ 始めました

かるあのメモ — Wed, 05 Sep 2007 06:49:46 GMT

週末の AdminTech 勉強会で TechEd の振り返りということで、 30分ほどですが尾崎さんとめさいあさんと一緒に LINQ セッションについて感想やディスカッションを交えてお話します。今まで LINQ to SQL は触ったことがなかった、というかむしろ避けていたんですがこれを機に週末からさわり始めました。

Community Convergence XXXI

Charlie Calvert's Community Blog — Wed, 26 Sep 2007 03:38:48 GMT

Welcome to the thirty-first edition of Community Convergence. This issue features links to seven very

IQueryable vs IEnumerable

Technoeuphoria! — Mon, 01 Oct 2007 20:17:27 GMT

At the most abstract level, LINQ (Language Integrated Query) can query against two types of provider

LINQ: Building an IQueryable Provider - Part VIII

The Wayward WebLog — Wed, 10 Oct 2007 00:49:25 GMT

This is the eighth in a series of posts on how to build a LINQ IQueryable provider. If you have not read

Scott Peterson: Linq Me This Nut

工程師的雞排攤 — Thu, 01 Nov 2007 11:04:07 GMT

The Banshee-to-Windows porting has been more or less done for a while and the code is about to be integrated

Architecting LINQ to SQL applications, part 2

Ian Cooper — Fri, 30 Nov 2007 15:58:32 GMT

What is LINQ? LINQ stands for Language Integrated Query and is a DSL within C# for querying data. It

Architecting LINQ to SQL applications, part 2

Ian Cooper [MVP] — Wed, 05 Dec 2007 16:25:24 GMT

What is LINQ? LINQ stands for Language Integrated Query and is a DSL within C# for querying data. It

An Updated LINQ to WMI Implementation

Eden Ridgway's Blog — Wed, 02 Jan 2008 10:52:13 GMT

An Updated LINQ to WMI Implementation

TerraServer Sample: A LINQ Provider

Charlie Calvert's Community Blog — Mon, 07 Jan 2008 04:34:52 GMT

Over the holidays Alex Turner, Mary Deyo and I added a new sample to the downloadable version of the

TerraServer Sample: A LINQ Provider

Noticias externas — Mon, 07 Jan 2008 05:33:45 GMT

Over the holidays Alex Turner, Mary Deyo and I added a new sample to the downloadable version of the

LINQ: Building an IQueryable Provider - Part IX

The Wayward WebLog — Thu, 17 Jan 2008 06:06:16 GMT

This is the nineth in a series of posts on how to build a LINQ IQueryable provider. If you have not read

Links to LINQ: Writing custom providers

dave^2=-1 — Fri, 01 Feb 2008 13:21:59 GMT

Just storing a couple of links for a rainy day: Mehfuz Hossain's LINQ provider basics article on Dotnetslackers

Links to LINQ: Writing custom providers

dave^2=-1 — Fri, 01 Feb 2008 13:49:40 GMT

Just storing a couple of links for a rainy day: Mehfuz Hossain's LINQ provider basics article on Dotnetslackers

LINQ Tips: Implementing IQueryable Provider

Shahed Khan (MVP C#) — Thu, 07 Feb 2008 08:49:21 GMT

Check out the following from Matt Warrens blog posts, if you are interested on how to implement IQueryable...

LINQ Tips: Implementing IQueryable Provider

Shahed Khan (MVP C#) — Thu, 07 Feb 2008 08:49:48 GMT

Check out the following from Matt Warrens blog posts, if you are interested on how to implement IQueryable

Jb Evain: An elegant LINQ to db4o provider, and a few LINQ tricks

工程師的雞排攤 — Tue, 12 Feb 2008 04:24:24 GMT

Last year, when I was working at db4objects on db4o , I insisted on the need for db4o to act as a LINQ

An explanation of Linq query providers

Alex Thissen Weblog Build 1.15.10.1971 — Thu, 20 Mar 2008 23:46:15 GMT

Linq query providers appear all over the place. Some say "Linq to Everything" to refer to all

LINQ to Entities: Combining Predicates

meek — Sat, 03 May 2008 03:31:12 GMT

Someone asked a great question on the ADO.NET Entity Framework forums yesterday: how do I compose predicates

Danny Simmons compares the Entity Framework to similar technologies

Wooley's LINQ Wonderings — Wed, 28 May 2008 05:39:20 GMT

It seems that everyone else is chiming in on Danny Simmons' recent comparisons of the Entity Framework

LINQ: Building an IQueryable Provider - Part X

The Wayward WebLog — Wed, 09 Jul 2008 02:27:43 GMT

This is the tenth in a series of posts on how to build a LINQ IQueryable provider. If you have not read the previous posts you'll want to find a nice shady tree, relax and mediate on why your world is so confused and full of meaningless tasks that it

[PL] Własny dostawca w LINQ (dla opornych) - cz. 1

Only Human | Devoted to technology v.2.0 — Thu, 10 Jul 2008 21:43:17 GMT

Dużo się mówi i pisze o tym, że LINQ jest elastyczne i rozszerzalne. Sam powtarzam, że aby podpiąć

LINQ: Building an IQueryable Provider - Part XI

The Wayward WebLog — Mon, 14 Jul 2008 22:18:30 GMT

This is the eleventh in a series of posts on how to build a LINQ IQueryable provider. If you have not read the previous posts you’ll want to do so before proceeding, or at least before proceeding to copy the code into your own project and telling your

Links of the Week July 25th

Chris Love's Official Blog - Professional ASP.NET — Fri, 25 Jul 2008 16:56:33 GMT

This week I am coming to you from the Microsoft Campus. So as you would expect I have a lot of energy

Building a LINQ IQueryable Provider - Part XII

The Wayward WebLog — Tue, 18 Nov 2008 04:00:02 GMT

This is the twelfth in a series of posts on how to build a LINQ IQueryable provider. If you have not

LINQ links

The Wayward WebLog — Tue, 18 Nov 2008 20:23:40 GMT

Part I - Reusable IQueryable base classes Part II - Where and reusable Expression tree visitor Part II

IQueryable vs IEnumerable

Jocelyn — Wed, 17 Dec 2008 13:46:23 GMT

At the most abstract level, LINQ (Language Integrated Query) can query against two types of provider

IQueryable vs IEnumerable

jocelyn — Tue, 06 Jan 2009 15:03:14 GMT

At the most abstract level, LINQ (Language Integrated Query) can query against two types of provider

LINQ: Building an IQueryable provider series

Floating Heart — Thu, 19 Mar 2009 17:49:18 GMT

http://blogs.msdn.com/mattwar/pages/linq-links.aspx Here's a list of all the posts in the building