Comments on: LINQ Expression Trees and the Specification Pattern http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/ A Developer's Melting Pot: LINQ to SQL, Entity Framework, .NET Security... Tue, 09 Mar 2010 16:19:28 +0000 http://wordpress.org/?v=2.9.1 hourly 1 By: David DeWinter http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-19120 David DeWinter Wed, 03 Feb 2010 02:44:07 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-19120 Unai, this is why Colin's method rebinds the parameters in the expression manually instead of using Expression.Invoke for EF. Unai, this is why Colin’s method rebinds the parameters in the expression manually instead of using Expression.Invoke for EF.

]]> By: Unai http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-19105 Unai Tue, 02 Feb 2010 22:01:06 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-19105 This And, Or operators using Invoke method in expressions and this method is not supported in EF 1 or EF 4 Best regards, Unai This And, Or operators using Invoke method in expressions and this method is not supported in EF 1 or EF 4

Best regards,
Unai

]]> By: David DeWinter http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-13778 David DeWinter Thu, 03 Dec 2009 01:26:26 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-13778 Do you have the Or extension method defined in your code? It's from Colin Meek's blog post <a href="http://blogs.msdn.com/meek/archive/2008/05/02/linq-to-entities-combining-predicates.aspx" rel="nofollow">here</a>. Do you have the Or extension method defined in your code? It’s from Colin Meek’s blog post here.

]]> By: marco souza http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-13719 marco souza Wed, 02 Dec 2009 06:43:57 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-13719 Hello, I am following your example, but ta experiencing an error when I try make the following code this.spec1.IsSatisfied return (). Or (this.spec2.IsSatisfied ()); Hello, I am following your example, but ta experiencing an error when I try
make the following code

this.spec1.IsSatisfied return (). Or (this.spec2.IsSatisfied ());

]]> By: David DeWinter http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-10823 David DeWinter Sun, 04 Oct 2009 00:56:25 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-10823 I haven't developed in Java for some time now, but a quick search reveals the <a href="http://www.theserverside.com/news/thread.tss?thread_id=46887" rel="nofollow">Quaere project</a> that is aiming to develop something similar to LINQ in Java. However, I am not sure there is anything that is quite as rich as the .NET implementation (which allows translations of these expression trees to any data source, like a relational database) that would allow you to compose these expressions into a SQL query. I haven’t developed in Java for some time now, but a quick search reveals the Quaere project that is aiming to develop something similar to LINQ in Java. However, I am not sure there is anything that is quite as rich as the .NET implementation (which allows translations of these expression trees to any data source, like a relational database) that would allow you to compose these expressions into a SQL query.

]]> By: Inanc Gumus http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-10812 Inanc Gumus Fri, 02 Oct 2009 21:08:02 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-10812 Hello David, Do you know any implementation like this in Java? Thanks Hello David,

Do you know any implementation like this in Java?

Thanks

]]> By: suhair hassan e http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-7594 suhair hassan e Fri, 19 Jun 2009 06:28:34 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-7594 Well written, learned a lot from this article, Thanks Well written, learned a lot from this article, Thanks

]]> By: Steve Burman http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-7248 Steve Burman Mon, 08 Jun 2009 23:15:06 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-7248 Nice article David. Well written. You might be interested in some of my articles at http://www.mostlyclean.com/category/Linq.aspx My pattern is not pure "specification" but I have been using it successfully with Linq.NHibernate for months now. Nice article David. Well written. You might be interested in some of my articles at http://www.mostlyclean.com/category/Linq.aspx

My pattern is not pure “specification” but I have been using it successfully with Linq.NHibernate for months now.

]]> By: David DeWinter http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-7229 David DeWinter Mon, 08 Jun 2009 01:40:39 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-7229 Glad the post is useful. Let me know if you are able to improve upon it when you start writing code! (And although my name sounds Dutch I myself am not!) Glad the post is useful. Let me know if you are able to improve upon it when you start writing code!

(And although my name sounds Dutch I myself am not!)

]]> By: worksol.be/ http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-7167 worksol.be/ Thu, 04 Jun 2009 08:53:17 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-7167 Hello David, I investigated the specification pattern in combination with linq and I got stuck on some techincal issues. This is the first post I read that explains it in good detail. Thanks very much to take the time to put in on digital paper! If you are serious about DDD than the specification pattern is essential and I hope it will get first class support in the Entity Framework best practices. Encapsulating business logic in 1 place and be able to use it while performing TDD is something very valuable. First chance I get I will test out your code PS Are you from Belgium/Holland? your name sounds very dutch :) Hello David,

I investigated the specification pattern in combination with linq and I got stuck on some techincal issues. This is the first post I read that explains it in good detail. Thanks very much to take the time to put in on digital paper!

If you are serious about DDD than the specification pattern is essential and I hope it will get first class support in the Entity Framework best practices. Encapsulating business logic in 1 place and be able to use it while performing TDD is something very valuable.

First chance I get I will test out your code

PS Are you from Belgium/Holland? your name sounds very dutch :)

]]>