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... Mon, 23 Aug 2010 19:55:42 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: Marcio http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-29388 Marcio Tue, 08 Jun 2010 13:22:04 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-29388 This post was very useful. I'm a Java Developer getting started with .NET and I was curious about how to implement the specification pattern on .NET. The LINQ framework and C# language are more flexible than Java Persistence API to implement this pattern. Thanks. This post was very useful. I’m a Java Developer getting started with .NET and I was curious about how to implement the specification pattern on .NET. The LINQ framework and C# language are more flexible than Java Persistence API to implement this pattern.

Thanks.

]]> By: peter http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-27595 peter Wed, 05 May 2010 23:18:08 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-27595 Hi! again! so "Product" is NOT on your entity model? So your Specification returns an expression not a bool (as per the original intention of the specification pattern)?? Your specifications are tied to Implementations and not interfaces correct? How would you do it would interfaces? I'm more interested in the repository layer Thanks Hi! again!
so “Product” is NOT on your entity model?
So your Specification returns an expression not a bool (as per the original intention of the specification pattern)??

Your specifications are tied to Implementations and not interfaces correct?

How would you do it would interfaces?
I’m more interested in the repository layer

Thanks

]]> By: David DeWinter http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-26782 David DeWinter Sat, 01 May 2010 00:07:59 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-26782 No, since Product is a domain object I can write it myself without worrying about what O/RM or storage engine I use. No, since Product is a domain object I can write it myself without worrying about what O/RM or storage engine I use.

]]> By: peter http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/comment-page-1/#comment-26466 peter Thu, 29 Apr 2010 11:22:31 +0000 http://blogs.rev-net.com/ddewinter/2009/05/31/linq-expression-trees-and-the-specification-pattern/#comment-26466 I'm assuming from the code above that Product is a domain object. Is this also the "Product" in entity framework tables..?? Are you not tying yourself to the storage implementation? I’m assuming from the code above that Product is a domain object. Is this also the “Product” in entity framework tables..??
Are you not tying yourself to the storage implementation?

]]> 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

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