I want to develop a C# <-> Database application. I've considered using a ORM creating me classes for transparent access to whatever database I want to connect to.
I found nHibernate. But this seems very heavy and complicated to configure.
My question: Is something out there that is lighter than nHibernate?
Thanks,
Andre
Edit: Love your answers. Nearly want to mark everyone as my favourite :)
You may take a look at Linq to Entities which integrates nicely with Visual Studio.
One of the easiest ones I've used is http://www.subsonicproject.com/
I found Lightspeed really easy to configure and use (much quicker than nHibernate). The express edition is limited to 8 mapped entities though so it is likely to cost you some money.
You can look at this set of posts "Build Your Own Data Access Layer" - it ends up building a lightweight ORM (and was written by one of the nHibernate contributers, Davy Brion).
From microsoft there are EF (entity framework) and Linq2Sql, though not sure that EF constitutes lightweight. See this comparison of EF and nHibernate (biased, as the writer is a heavy nHibernate contributor).
nHibernate is not complicated to configure. But I agree that it's sometimes too much for simple applications.
When I don't use nHibernate, I use simple ADO.NET objects.
When I don't use nHibernate, it's because ORM will be counter productive.
Related
What is the current status of linq2sql and is it sensible to use it still?
I am about to start a very large project and have quite a lot of experience with it.
However I don't want to avoid EF if that is really the way to go. I do like the simplicity of linq2sql.
In my opinion: no.
Why?
EF in v4 is just as easy to get started with as Linq-to-SQL
EF 4 also has options to do more complicated and advanced things - if you need to. No luck in Linq-to-SQL, really - it's simplicity is all there is - no advanced features
EF 4 has various approaches to building your system - Linq-to-SQL only has "database-first"
EF 4 allows you to update your model (if you're using the database-first approach) if your underlying database ever changes - is there any change it might?? No such luck with Linq-to-SQL - drop the table and drag it back on; tough luck if you modified table or column names, or added additional e.g. associations...
Linq-to-SQL was really more of a proof of concept to show off the capabilities of LINQ, developed by the C# language team. It was never really meant to be a full-fledged ORM. EF on the other hand was developed by the ADO.NET database team, and was intended to be a real enterprise-grade ORM / conceptual data model. Linq-to-SQL will not see any further development to speak of - maybe a bugfix here or there. EF on the other hand is Microsoft's strategic platform - they'll heavily invest in it and continue development here (see e.g. the "EF Migrations" to automagically update your database schema from within code).
My personal take: if you start new and you're on .NET 4 (or can go with it): go with EF v4. You can't go wrong, you have all the niceties of Linq-to-SQL - and then quite a few more, if you need them some time in the future....
Personally I'd try to make it such that the database layer is an implementation detail, behind a view-model, repository layer, and other such devices. Then the only question is:
does it work?
To which the answer will probably be "yes", but by abstrating that you can change it without much risk / re-work. Perhaps to the "fuller" ORMs (NH, EF, LLBLGen etc) - or perhaps the lighter micro-ORMs (dapper, simple.data, massive etc).
If L2S lets you get started quicky, there's no reason it can't be used. It might not be my first choice now, but it is a good tool, and I find it more intuitive than EF in many areas.
The key, though, is not painting yourself into a technological corner where change is too expensive.
Linq-2-SQL is dead... no matter you hear around
http://blogs.msdn.com/b/adonet/archive/2008/10/29/update-on-linq-to-sql-and-linq-to-entities-roadmap.aspx
I use visual studio 2005 , but recently I've heard that there is a new technology which called entity framework .. should I move on and use it instead of using the usual SqlDataReader !!
the most important thing to me is the performance , note that I get the data from the DB using DataReader and return it as a generic List ..
any suggestion .. thanx :)
The SqlDataReader and the Entity Framework are two completely different approaches to access your data. With SqlCommands, you yourself write the SQL queries. With an O/R mapping technology such as the Entity Framework, the relational database structure is mapped to objects whose properties you access, e.g. Linq to Entities. Note that the O/R mapping approach is not about speed.
If you are in VS 2005. I think you can't use Entity FrameWork. For that you required 2008 and .NET 3.5 SP1. Entity Framework has some issues. If you are going with Entity Framework; go with Visual Studio 2010 and .NET 4.0. This will be a better option.
Latest update from Scott Gu
If you want to switch to Linq to Entities then yes, you will need VS2010.
Or you can stay with VS2005/2008 and use nHibernate or similar framework.
But none of those ORM tools is (primarily) about speed, so it may not be the right thing for you.
The reasons for switching to an ORM framework would be to use a more OOP approach, ie to replace your generic list.
Look through a few demos/walkthroughs to decide if it is something for you.
I'd recommend to write up your requirements, then identify the options, evaluate each option with some tests that are meaningful for your requirements (e.g. ease of use, speed, etc.), and finally decide. With some smart design and implementation choices you might even be able to switch between some of them with relatively limited effort at least at the beginning.
The Entity Framework is certainly an option. I'd recommend to also include NHibernate and in particular fluent-nhibernate in your investigation. Good luck!
If you consider performance, see here
http://toomanylayers.blogspot.com/2009/01/entity-framework-and-linq-to-sql.html
http://blog.codefluententities.com/2012/06/05/codefluent-entities-performance-comparison/
Traditional ADO.NET (without ORM) is the fastest way. If efficiency is a key issue then better stay with "SqlDataReader".
Writing the queries yourself still beats any automatic process performance-wise. Entity framework makes the data layer more abstract, which improves portability and readability.
I just read this article about the Entity Framework 4 (actually version 2).
Entity Framework seems to offer a huge improvement over its first release. Thus, I have never ever used EF in any project, since I think EF is not mature enough in comparison to NHibernate.
NHibernate and its current contributions of FluentNHibernate and Linq for NHibernate by Ayende Rahien
My feeling is that Microsoft is solely trying to gain terrain it has lost in favor of NHibernate when the 2nd version of NHibernate came out. Nevertheless, my concerns are the followings (not in particular order):
Will EF4 tend to be less XML-verbose?
Will EF4 be compatible with underlying datastores other than just SQL Server?
What are the greatest benefits of going with EF4 instead of FluentNHibernate or NHibernate itself?
NHibernate is a great tool, I guess everyone agrees. Due to its predecessor Hibernate, we may easily find documentions and tutorials and sample applications to get acquainted with it. This is not the case for FluentNHibernate. Particularly as per the project I'm working on right now which demands that I investigate further about NHibernate and its options (FluentNHibernate for instance) in order to document the rules of usage and the best practices of NHibernate and FluentNHibernate technology. Thus, being handcuffed with VB.NET, being a C-Style developer, I can't find some syntax equivalencies in VB.NET for the examples provided, though I made my way so far.
I do believe that NHibernate is a best choice, but as a software consultant, I can't (don't want to) miss important technology changes, improvements and evolution.
Despite the bad comments I read about EF1, EF4 seems to be very promising. What you all think about both NHibernate and Entity Framework avenues? As for me, I am becoming puzzled with all that readings. I need you to bring back my head out of the water.
Thanks to you all!
I know almost nothing about EF, but a quick skim of the links provided leads me to believe that EF has no equivilent to Fluent NHibernate's Automapping functionality.
Edit: Some of the commenters pointed me to links indicating there is some automapping in EF, but it's not really clear if it's as powerful as FNH (for example, being able to automap collections of other objects).
Personally, I love being able to design POCOs in an OO manner, and letting the tool handle all the busy work of mapping to a relational database.
FNH still has the most powerful automapping capability, as far as I know.
Go to Fluent NHibernate Automapping for more info.
Will EF4 tend to be less XML-verbose?
In general, I have not seen any indication that the XML will be drastically different. Microsoft is providing a Fluent like interface to EF in v4, but it's an add on / separate download.
Will EF4 be compatible with other underlying datastore than just SQL Server?
It is compatible now and it will remain compatible going forward. LinqToSql is SQL Server only, but EF has never been SQL Server only.
What are the greatest benefits of going with EF4 instead of FluentNHibernate or NHibernate itself?
Honestly, there aren't many. There are little things here and there that are different, but in general NHibernate is still years ahead of EntityFramework, even in EFv4.
As a consultant, it is probably worth your time to become an expert in both NHibernate and Entity Framework. You will probably continue to see them both in the real world. Microsoft tends to have a short attention span when it comes to data access so it's not clear where Entity Framework will be a couple of years from now. Because it's from Microsoft, you can be sure that plenty of developers will use EF.
Take this with a grain of salt. I am not any kind of authority on ORM tools, but here it goes...
One of the biggest benefits that i see in EF is the GUI for mapping. IMO, this saves a lot of time, but is probably the reason why EF XML mappings are so verbose. They're not made to be dealt with manually, unfortunately. Whether it will change or not i don't know. What i do know is that the GUI that EF provides used to be very flaky in previous releases. And i still hear about people complaining that it isn't scaling well, especially on larger and more complex schemas where it just misses things and you end up messing with the mappings directly. My opinion is that XML maps will become less verbose as EF matures. You also have the fluent mapping support in EF, which is also helpful. Finally, another big thing is the ability to change code templates that EF generates, that is if you favor database-driven design instead of design-first approach.
Another benefit is that it comes from Microsoft and they have enough dough to make this a really dope framework. It has grown tremendously in the past few years. I think it'll be on the same ground with NHibernate in a little over a year. As of now, I think NHibernate is a better choice. It's more stable and mature. Relative easy to configure and most importantly a better performer. I think if you design wisely, a move from one to another is going to be a piece of cake.
EF is just an abstraction. I believe there are providers for Oracle, so i don't see why there couldn't be more added as it grows.
Given that I'm very good with SQL and c#,
Should I learn another layer on top like NHibernate ?
Is NHibernate just a library (that stores in a Database)? Or it's a service?
Should I use NHibernate or ADO.NET Entity Framework?
If you think I should learn/use an ORM, give me your top reason.
You should use an ORM as long as you need to convert database data to and from business objects, since it will save you a lot of work and will allow you to focus on your application logic.
NHibernate is a .NET library that does just that, mapping .NET objects to database tables according to how you configure it. In this sense it is the same as the Entity Framework, only that EF is already embedded in the .NET framework and NHibernate is a separate assembly that you must reference in your project.
Last but not least, if you use SQL Server you should add LINQ to SQL to the list of possible ORM candidates, it is simpler that EF and for many scenarios it is more than appropriate.
It depends on your applications.
NHibernate is a library. So it's a DLL.
Depends on what you want. NHibernate is based on Hibernate which is battle tested.
It doesn't matter how good anyone is with SQL or C#. There is a fundamental gap with the tools when dealing with SQL and C#. Aside from all the other productivity boosts that I've had when I learned to Stop Worrying and Just Use an ORM, I found only having to deal with C# most of the time has helped greatly. I have far fewer impedance mismatches in my work now and I do believe that contributes to fewer bugs.
Less code you have to write is less code you have to maintain. ORMs allow you to worry less about certain details so you are free to concentrate on higher level tasks.
No, I tried Fluent NH and Castle Active Record and Spring Framework NH Extensions but they all obscure basic operations and make things less visible. Start using native NH, then add a layer after a year.
Yes, NH is a library, not a service. But the way you use it in your code makes it feel almost like a service (e.g. a data repository service)
I tried EF and found it nauseating so I would go with NH
For OLTP-like systems, ORM is the way of the future. Not using ORM for me is like not using unit-tests or programming in non-OOP language.
Probably, but it depends on what kind of applications you normally write.
NHibernate is primarily a DLL, but there is more to it than that.
NHibernate (Read this for more details: NHibernate, Entity Framework, active records or linq2sql)
My top reason would be so you can use Linq. Right now, you pretty much need an ORM to use Linq.
Unless it's a very small application, then the answer is 'yes'.
Library.
I hear people swear by the EF, but I'm very leery of it. I also don't like tying myself to all Microsoft technologies. NHibernate would be my suggestion.
First, you don't want to go through the time and headache of writing all the SQL and classes and such; it's just not worth it. Second, it allows for greater ability to switch from one RDBMS to another without having to change much code. Third, it'll give you more control in the future in terms of database abstraction and such.
The question header is clear, i want to know why its different and why, when to select it for my project?
I wrote a blog post on this a while ago. In short, it takes a fundamentally different approach to ORM than Hibernate, ECO, and the other ORMs that I have looked at. You may think this approach is better, worse, or unimportant, but if you look deep enough it's hard to dispute that it is different. But don't take my word on it. If you're really interested in this subject, I strongly recommend reading this technical paper and this interview in ACM Queue.
This is probably not the answer you are looking for but I dont think you should use it in your project. It is very young and not very complete. Wait until the next version comes out.
If you insist on using Entity Framework there are a few good things about it. A nice one is the way it allows for complex mapping in a very simple way. And of course because it is a microsoft technology the IDE integration is nice.
But like I said, I tried it and I dont beleive it is ready for real use.
Anyway good luck at your project
ADO.NET is not an ORM.
Basically the difference is the level of abstraction used in each one.
With ADO, you basically query the DB and use the results as objects, is like a bridge between the RDBMS and your objects.
You model your DB and then you create object from that model. That's why it is an Entity Framework ( db entities )
ORM are not for querying or represent database records as objects ( although that's how everyones uses them anyway - me included - ) but a way to persist your object model into a relational database.
They are Object to Relational Mapping ( not Relational to Object Mapping )
So, you choose one or the other, when you have a domain ( object ) model and you want something to persist it ( to a RDBMS ) or when you have a entity model and you want to use it as objects in your app.
From what I've read, it has good support for WCF remoting/binary serialization, which is something many ORMs don't support very well (if at all). It might be worth looking into if you want to create a rich client/server/remoting app with ORM on the client side.
What different? It didn't learn from all the other ORMs.
Here are the issues I've been tracking for InfoQ
Does LINQ-to-Entities really return different results depending on previous queries?
Working Around Entity Framework's Large Data Model Issues
No Change Tracking for ADO.NET Entity Framework 2010
And this tool is a must-have if you do decide to use it.
Meta-data Synchronization Tools for LINQ to SQL and ADO.NET Entity Framework
Some of the best talent in the ORM world in .NET seem to be working on projects such as NHibernate (free-open-source; I use it) and LLBLGen Pro (commercial).
NHibernate is the reigning standard for enterprise-quality full-scale multi-vendor ORM. NHibernate is also the reigning standard for a pure implementation of ORM, permitting you the developer to write domain models completely independently from the NHibernate infrastructure, and completely eliminating code-generated classes.
NHibernate may look scary at first. But it is actually fairly friendly once you work with it a bit, and work has been underway since July to make NHibernate nearly configuration-free.