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While I was planning to write about the same topic and have the draft ready in my Windows Live Writer waiting to complete, I found an interesting question in StackOVerflow and couldn’t just resist to answer:

ORM/Persistence layer Advice

The question starts with:

I'm starting a new project and I'm looking around for either a very good ORM or for a non-SQL-based persistence layer.

Then follows up with a REALLY GOOD summary of what he believes about each known ORM he knew out of his own findings and search. I advice you to go read it.

However, all this investigation didn’t get him to a single choice answer. And I can’t blame him. This is one fo the questions that will remain for so long without a single answer, or maybe having the popular “It depends” answer.

I have had a LONG research in this topic as well. I have read for so long (and watched videos/casts) to make sure of the best usage of many ORMs and then used them sometimes in test projects sometimes in production, and I wanted to share my thoughts based on this. I posted a long answer there on the question in StackOverflow, and I want to share this answer with you here. I may also have a second part of this post based on my existing Windows Live Writer draft, but, based on my previous times, I think I won’t!

Let me first quote some parts from the question itself:

I also want to avoid at all cost having to mess with string-based queries so tools supporting LINQ or otherwise intuitive and possibly strongly typed queries get a big bonus.
Finally working with POCO objects is another thing I'd really want to do
Here's a list of products I've evaluated and why they don't fit, just so that I don't see any advice about using those:

NHibernate: crazy xml stuff, too much set up, high maintenance complexity and cost for model changes, session factories are messy and don't fit well with my needs

Castle ActiveRecord: NHibernate based, little documentation plus some problems related to NHibernate still apply. Furthermore, to get decent models it takes so many attributes that one is better off creating the schema manually, and the way relations are handled is a shame.

Linq To SQL: missing POCO objects and according to MS it won't improve much overtime (EF is what they're committed to)

Entity Framweork: although in v4 POCO objects are possible, they're still pretty hacky and force you into doing too much manual work to set things up. Besides, v4 is just a beta

LLBLGen Pro: good, especially with SelfServicing adapters, but not POCO. Also, the LINQ provider isn't perfect yet. Finally, deleting a group of objects is not possible via LINQ which results in mixing APIs (one of which is far from intuitive) and that I don't like.

SubSonic SimpleRepository: for a few minutes I thought I was dreaming. The deam came to an end as I figured out how the thing didn't handle relationships

Here was my answer:

If you can afford LLBLGen license, go for it.

I seriously don't like LINQ query-syntax the more I work with it (although I LOVE the language features related to it like Extension Methods and Expression Tres).

I loved at first like everybody else, but being uncertain whether [[ where employee.Name.StartsWith("John Smit") ]] in that XYZ LINQ provider will be done in SQL statement or in LINQ to Objects (after the SQL returns all results), and whether [[ user.Roles.Contains(role) ]] will at all work or not is a big step behind.

LLBLGen can make deleting all items without loading them as easy as

MyEntityCollection.DeleteAll( new MyEntity {Condition = value} );

This is pretty simple and I like it. You get lazy loading and you set eager/deep loading by default and/or per query using Prefetch API. You can compose and construct dynamically (and easily) any filter/sort/loading at infinite levels. It's very nice.

There are only two problems about LLBLGen: first, it's price not all companies would love to pay especially given the hype Microsoft alternatives have. Second, the naming convention although standard in RDBMS theories) like PredicateFactory instead of "where" or "filter" and Prefetch instead of deep loading and even SortExpression instead of orderby, those all are a little scary to a developer working with it for the first times, but soon you learn to love them, given the power and ease they give. There are talks about POCO support in LLBLGen 3.0. I cannot tell about it because I don't know.

Now given I no longer work in a company that uses LLBLGen, the company uses LINQ to SQL mainly because it's "proven" in so many projects without big failures (unlike EF 1, which is lacking even LINQ features in LINQ to SQL and has very bad performance and can be quite limiting in advanced mapping - which it should have been best for!). This website StackOVerflow itself runs on top of it!!! I used both in this company (EF after L2S) and hated both. The decision for new projects remained LINQ to SQL, and doing all we can to overcome it's limitations. You can work around it to do SEMI-POCO (you still need to use some L2S related types when it comes to associations).

I also do some small projects at home. Since I nolonger have LLBLGen license, I decided to learn NHibernate and use it along with Fluent NHibernate and LINQ To NHibernate. I have learned through this that NHibernate is VERY strong. It changed how I work by some features like updating DB schema automatically (I never touched the DB almost when using it). LINQ provider (in NHibernate Contrib project) is quite lacking sometimes but there is the unreleased source code of NHibernate itself contains a better LINQ provider (haven't tried it yet). The "Session" in NHibernate has problems when you are doing web development similar to those related to DataContext in L2S or ObjectContext in EF (LLBLGen doesn't suffer from those thanks to self tracking entities).

The biggest problems I had with NHibernate though was ability to find information. Too many pieces that should be put together in certain way and not much guidance can include advanced information for both mapping and querying. If not I had a friend (Tuna Toksoz , @tehlike on twitter) who happended to be a committer in NHibernate project source code, I'd really be in serious trouble.

The moral I learned was: If you want something that just works and a bit basic use Linq To Sql or SubSonic, if you want something in the middle and your production environment can afford BETA .NET version (given golive exists) use Entity Framework 4.0, if you want something very powerful and can afford the hard learning process go to NHibernate, AND, BEST OF ALL, if you can afford LLBLGen, USE IT.

Let me know your own thoughts on the topic.

Today (technically yesterday, since it’s 3:26 AM already while I’m starting this), Mr. Adam Mohamed Meligy finally arrived home, after staying 9.5 days in nursery. This –dear audience- given Mr. Adam arrived to our world only in October 5, 2009, a date that the entire world will (sooner or later) always remember!

Mr. Adam is now taking a personal cover, pretending to be a normal baby, while he is pretty professional, he cannot sometimes hide his special natures, being relatively quiet compared to normal babies, and highly responsive to touches and (believe it or not) spoken notes/requests.

These are things that the world will remember once Mr. Adam finishes his first big achievement in the field he will take up for living (God Willing). Some other small details matter more to the family, both his grandparents –for example- note him as their first grandchild. I –personally- recognize him as my extra chance in life! If I fail to manage to be another Anders Hejlsberg/Martin Fowler, Scott Guthrie/Brad Abrams, or Scott Hanselman/Rob Conery/Phil Haack (still trying), Mr. Adam has a bigger chance; else wise, he’ll be digging his road as a notable figure in some different field (God Willing).

I feel that I was blessed with not just two more legs and hands, one more tongue and a couple of stronger eyes, extra more years to live, but also with an extra brain and superpowers. You can always upgrade your thinking methodologies, even reinvent the way you think completely, but you are always limited to your physical brain constraints that -although can be always stretched more and more- have their limits. Now I have an extra brain that can do pair thinking with me and reinvent the way things happen by the experiences he will be having on his own (God Willing).

So, this is to log that Mr. Adam (temporarily until he decides to replace that with “Eng.”, “Dr.”, and/or “Prof.”) has just finished implementing phase zero,  coming to existence!

Few More Facts About Mr. Adam’s Arrival

• The exact time of arrival to world is October 5, 2009, 10:30 AM Abu Dhabi Time, that’s 8:30 AM Cairo Local Time (CLT), 6:30 GMT.
• Although born in Kornesh Hospital, Abu Dhabi, UAE, Mr. Adam holds the Egyptian nationality, just like his parents. He also inherits the Islam religion, which he will be (God Willing) discussed about as soon as starts making conversations, so that he practices it for the sake of belief, not inheritance!
• Mr. Adam reached our world after hiding in a secret cafe for slightly less than 35 weeks, reaching our world at the weight of 2.25 Kg.
• Mr. Adam has his email, Facebook and twitter accounts created on the day of arrival and moderated by parents. Soon (God Willing) he will be running those himself, and creating his own LinkedIn account on his own once he finishes his first school and starts a professional expert career simultaneously.
• Mr. Adam has come with the message to make the world a a better place to live for humans, not to dominate the entire world ;-).
• Since arrival, the protocol requires using the prefix “Mr.” when mentioning Mr. Adam’s name in conversations. Only tweets/categories, etc… are allowed exceptions due to technical/official nature. This prefix is temporary as per the relevant note above.

On behalf of the family, I congratulate the world on having Mr. Adam with us. I’ll be following up with his significant news until he starts blogging (hopefully soon, God Willing).

Few minutes ago a colleague and friend asked me about some problem he was having with ASP.NET themes. He was using a theme and including a CSS file in it, the CSS file was linked in the generated HTML but clearly it was not applied. Putting the URL of the CSS file in the browser address bar would return an empty result in Firefox, and a crappy DOCTYPE,HTML,HEAD,BODY tags in IE. The same website works normally with other developers running Windows XP or Windows 7.

Going further to the problem, I tried checking the file access, giving extra permissions and so on, checking web.config and global.asax for any ASP.NET HTTP Handler or HTTP Module that might be handling all requests. None of this existed. Then, I switched to IIS, trying to change the website from custom Application Pool to default integrated pipeline one to default classic (IIS 6 like) one, but no use.

Now I started thinking, images in the website didn’t show also! I didn’t know whether this was a DB/code issue or related to not showing the CSS, well, maybe something is wrong with IIS installation, right? Well, exactly!!!

Here’s what the problem was:

Having installed IIS 7.5 for the first time, the guy thought he just needed to choose ASP.NET features in WWW, he never realized he has to have “Static Content” checked as well. It was really funny when discovered!

Wouldn’t you agree?

Few minutes ago, I saw @mShady, my dear friend (Real life friend, not just on twitter) tweeting:

RT @ASGEgypt: RT @scrum_coach: Should the team be allowed to drop the retrospective? http://bit.ly/bkOgv  #scrum #agile #lean #xp #kanban

I checked the post and found the options are:

1. Yes, It’s their process why not?
2. No, explain to them and work through why the retrospective is so important.
3. Maybe, if they are no longer a team then why continue with Scrum?
4. Only do retrospectives once a quarter and build up a good list of things to change.
5. Yes, the process will take care of itself we don’t need to watch it that closely. After all it’s common sense!

Interesting question! Not the most important topic in Scrum but like the way Agile works in general, if you play with it wrong, it is an indicator you have something else wrong as well before that, so, it gives you an alert.

See the rest of the blog post. I find the options my main interest, and wanted to share with you here how I answered this question:

I’d say have a really short one if the team members have been working together for sometime it can go really quick (an hour or so) just before the planning for the next sprint. We used to do so in a previous company and it was pretty successful.
It was like it’s one meeting divided into 2, one hour or so for previous sprint retrospective, and probably rest of the day (or most of it) for the planning for next sprint.

If they cannot have a quick meeting like this quickly then something else is wrong and they need to work on their team skills. Time boxing would be one option: The meeting will be needed “more” if they do not communicate well, Time box it to 2 hours or so and make it clear and strict since beginning, and consider investigating (assuming you are scrum master or team leader) what other issues the team may be suffering from.

However, I find myself going with (1) and (5) at the same time, “it’s their process” and “After all it’s common sense!”.

What do you think??