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It’s finally here, an Entity Framework 4 provider for oracle, complements of Devart . You can download the provider (trial version of course) from here , look for version 5.55 beta.
Just finished passing my presentation about ORM & Entity Framework basics This presentation is part of a whole-day seminar about ORM Tools & Concepts Currently Bernie & Erez are demonstrating NHibernate & Entity Framework head-to-head and later on Gil will deep dive into Entity Framework and Erez & Bernie will once again join forces to talk about Data Access Pattern in the real world. We’ll finish the day with an Expert Panel, where Oren Eini will join us to talk about ORMs, NHibernate...
First time that I can say – there are MANY people that use EF4. How do I know? because the session had the room filled with people, with people waiting outside ! EF 4 is great. It solved many of the problems of EF3.5 and made the technology more mature and useful. What annoyed me in the lecture is that it showed all the features of EF4 that people already know of (well, I know of). The title was misleading because I thought they will talk about new features that don't exist currently. Here is...
As I've stated before, I attended the data programming and modeling session - And I enjoyed every minute. Chris Anderson and Don Box rock ! They talked about Entity Framework 4 – The automatic lazy load (no more need to call the damn Load() method), different approached of model first, POCO and code only (using the fluent API) etc. There was a talk about code first having a configuration class instead of writing all the fluent API by hand, and without having to add attributes to your POCO classes...
Wow ! I’m not familiar with events of this size. For me, Israeli Tech-Ed was the biggest event I attended. Well, there’s something strange about flying 20 hours to the far end of the world, going to a city with million of people of different types, and entering a conference center will thousands of geeks moving around. First Keynote was interesting, a lot of talking about “3 screens and a cloud”, cloud in general, Azure in specific. Many new features in VS2010, IIS, and Windows to support all the...
Last week, a colleague of mine asked me to create a sample composite design pattern model in Entity Framework. I thought to myself, no problem, created the table that contains the Component, Leaf & Composite entities (according to TPH – Table Per Hierarchy) and went to build the EDM based on the table and there I started to have problems which needed manual fixing. Since I’m working with EF 3.5, I’ve built the DB prior to the model – In EF 4.0 you can do model-first and build your db by script...
A few day ago, a colleague of mine, Shlomo Goldberg , raised a question about Entity Framework and large models. Another colleague of mine, Gil Fink posted some links to helpful tips for using large models, and I want to talk about one of these tips – using the View Generation option. If you’ve worked with large models in Entity Framework 3.5, you probably noticed that as the model grows, it takes more time to initialize the ObjectContext for the first time. A solution to this is to use view generation...
Just wanted to say I had a great time giving this lecture. I’m pleased to hear people learned more than just about entity framework. Big thanks to Noam King for inviting me to give this lecture, and to Guy Burstein & MS for the accommodations. I’ve uploaded the presentation, code samples (Both EF 3.5 & 4.0) and the sample DBs I’ve used (as .MDF files, you’ll need to attach them to your db to make them work). You can download the entire file from here .
The IDCC sessions are open for voting Among the session, you can find 2 of mine : 1. Creating Data Access Layers with ORM tools After Entity Framework came out, I kept hearing people say “They say EF is good, but NHibernate is more mature, so why use EF?”, so in this session we’ll take a look at the two ORM tools, how they work and how you can use them to build a DAL for your application – you’ll be the judge. There are 2 more recommended session about Entity Framework from two of my colleagues at...
A few weeks ago I've published a post regarding DataDirect's new Oracle provider that supports EF. I was able to download DataDirect’s provider only this week, so it will take me a few more days to examine it and post some notes. As for now, I would like to share with you some of the issues in EF we’ve came across migrating from Sql Server to Oracle, using the provider from DevArt . BTW, we haven’t fully migrated to Oracle just yet, our project supports working with both databases using a...
Entity framework supports creating an entity type that holds binary data (byte[]), this is useful if you need your entity to hold things like file streams, photos etc. But there is a problem when your entity has a property of type binary. If you’ve worked with EF and N-tier applications, you know that you can serialize your entity and pass it to the client, deserialize it the client-side, change it and the send it to the server to be updated. MS suggests using the ApplyPropertyChanges method of the...
The answer to the above question should be “nothing, unless you’re trying to build a project that references entity framework”, but apparently it isn’t so. Say you have a project you’ve built, and you want to build it through code, using the Engine class of Microsoft.Build.Engine assembly. The code should look something like this (taken from MSDN): // Instantiate a new Engine object Engine engine = new Engine(); // Instantiate a new FileLogger to generate build log FileLogger logger = new FileLogger...
Entity Framework supports entity inheritance, which is a basic requirement for O/R mappers. When exposing a model through a service, either an ASMX WS or a WCF service, a WSDL will be created that among other things describes the structure of the entities, including the inheritance tree of the entities - This is done to allow creation of methods that return polymorphic types. EF supports derived entities through WCF services with data contract serialization using the KnownTypeAttribute which is added...
MetaLinq project now supports serializing expression trees with XmlSerializer. For further information about this project, read my previous post on the subject.
One of the least explored field in Entity Framework is what happens to your queries when you work with a large set of entities and hierarchies. When querying an entity that has a -to-many relations, the generated query is a simple query - contains only the fields of that entity. When querying an entity that has a -to-1 relations (1:1, N:1, 1:0..1 ...), the generated query contains the fields of the queried entity and the keys of every -to-1 relations. This was made to allow the related entities to...
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