What are the advantages of EF4 or LINQ to SQL?

What are the advantages of EF4 and under what circumstances is it preferred over LINQ to S开发者_如何学运维QL?

LINQ to SQL will have no more future development. So EF is the way to go in the future.

Entity Framework vs LINQ to SQL (this should explain what you want to know)

Well, two of the major differences are:

1) EF can target multiple database engines, including Oracle and MySQL. Not just MS SQL Server.
2) You can do so-called "code first" schema development. Basically you create your object model, and along with some hints, EF will generate the schema for you.

Seems to me that Linq to Sql is great for rapid prototyping and simple CRUD scenarios. Anything more advanced or enterprisey would use EF4. (Or at least that's what MS would like us to believe :) I've had good luck with Linq to SQL in production, for what it's worth.

EF4 basically adds a whole bunch of OO-ness to the mapping that isn't present in LINQ-to-SQL, such as rich object inheritance models. My own take on it is that none of that is necessary for good design, and I have yet to come across a single scenario in my own work that warrants the added complexity EF4 brings to the table.

Having said that, Microsoft has deprecated LINQ-to-SQL and will not continue developing it, so it will eventually fall behind EF4 in capability and efficiency (if it hasn't already). So the pragmatic choice is simple: go EF4.

After trying both and spending over one weeks porting a project from linq to sql, I can say that I really prefer Linq to SQL. The main reason for this is that EF is more restrictive on what functions you can use in LINQ queries. In EF I had to cast my linq expressions to a list to be able to manipulate them any further. Sorry for not being able to remember any example, it's been a few months since I did this...

One of the really big plus sides for EF, is the ease of use in connection with WCF Data Services. Very handy if you are developing a web site that should have an RESTful API.

Also, even though Linq to SQL is quite mature, it is indeed a dying technology. It won't get any significant updates, that makes it harder to commit to Linq To SQL for a new project.