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<ServiceContract()> Public Interface IDocumentService <OperationContract()> Sub SaveDocument(documentInfo As DocumentInfo)
Introduction In this post we will be discussing how DbContext API helps us in validation of entities in Entity Framework Code First workflow. The API allows various options to define validation of entities and their properties. It also makes it easier to execute these validations providing validation results.
As I was playing around with Entity Framework code first and ASP.NET MVC, it became pretty obvious that caching of some of the EF query results would be pretty handy. For example, if you look at my post that includes a simple ASP.NET MVC blogging application, you could see that I have to keep fetching the list of categories every time I render the blog entry screen. This is because I want to keep my application stateless. This is not very efficient.
We have just released a sample that shows how to extend Entity Framework in interesting ways by plugging into ADO.NET provider interface. The sample provides two extensions: EFTracingProvider – which adds the ability to log all SQL commands that are executed (similar to LINQ to SQL’s DataContext.Log EFCachingProvider – which adds transparent query results cache to EF The sample comes with implementation of distributed cache which uses Velocity CTP 3 as well as an adapter for ASP.NET and simple in-memory cache implementation. Because the sample is quite large and uses many advanced techniques, it’s impossible to fully explain it all in one blog post.
Scenario: In order to make applications perform it makes a lot of sense to cache commonly used reference data. Good examples of reference data include things like States, Countries, Departments etc.
Exposing the ORM Cache Familiarity with ORM caching issues can help prevent performance problems and bugs. In the early 1990s, when object-oriented languages emerged into the mainstream of software development, a noticeable surge in productivity occurred as developers saw new and better ways to create software programs. Although the new and efficient object programming paradigm was hailed and accepted by a growing number of organizations, relational database management systems remained the preferred technology for managing enterprise data. Thus was born ORM (object-relational mapping), out of necessity, and the complex challenge of saving the persistent state of an object environment in a relational database subsequently became known as the object-relational impedance mismatch. Complex problems sometimes demand complex solutions, and ORM software is no exception.
ObjectContext и DbContext в Entity Framework (EF) поддерживают информацию о состоянии сущностей, которыми они управляют. Но, как только контекст выходит из области видимости, данная информация перестает быть доступной. Это называют кешированием первого уровня, и оно действует лишь в течение жизненного цикла транзакции. Если вы пишете распределенные приложения с применением EF, где контекст часто меняется (а значит, ваша информация о состоянии доступна не всегда), кеширование первого уровня вряд ли обеспечит ваши потребности.
Repository, Specification, Unit of Work, Persistence Ignorance POCO with Microsoft ADO.NET Entity Framework 4.0 Beta 2 « KITCHAIYONG.NETi 15 Votes Preface As of preparing this writing and the source codes, I was using the .NET Framework 4.0 Beta 1, Visual Studio 2010 Beta 1 and ADO.NET Entity Framework Feature CTP 1 .
Friday, someone at Stackoverflow asked how to hide LINQ enabled persistence frameworks behind an abstraction (the repository pattern ). I pointed him to a question on Stackoverflow that I answered a few days earlier in what I explained how to allow your LINQ to SQL project to be unit testable. Friday’s question however, was about being able to easily change the O/RM later on, and specifically with multiple data stores / databases involved. Let me start by saying that due to the current difference in behavior and quality between both open source and commercial LINQ provider implementations, it is hard to completely abstract away such implementation, while still allowing to use LINQ to Expression queries that are effectively translated to database queries.
На днях, а точнее 12 января увидел свет Entity Framework 4.3 Beta 1 . Основная тема этого релиза – EF Code First Migrations. Помимо этого, есть несколько изменений, которые тоже имеет смысл упомянуть.
More than a year ago I was blogging about how to map private/protected/… properties in Code First CTP4 for the time being. Well it a long time and a lot of changed. The code there isn’t absolutely up to date with current Entity Framework 4.3 .
Introduction In these days i started use EF code first and think about how could i take the advantage form it for my recent project. My project is base on MVC3 and there are some challenges to continue update this project. At that time i must finish my job in a very shortly deadline so fast so good i just define some data access interfaces and implemented them with EF4. There are some things in my project troubling me:
In my previous post I demonstrated how to create a simple mapping using the latest EF4 CTP. In this post I will look at how I can customize some infrastructure code in an attempt to align EF POCO “Code Only” with existing patterns, while potentially increasing reuse and testability. A popular pattern for ORM data access is the Repository pattern.
In my last post on POCO , I mentioned the fact that there are two types of change tracking possibilities with POCO: Snapshot based Change Tracking and Notification based Change Tracking with Proxies. In this post, I would like to drill into both options a bit further and cover the advantages and disadvantages of both, along with the implications of using either approach. We will also be posting ideas on the EF Design Blog regarding some of the feedback we have received so far about POCO support in Entity Framework 4.0.
Home / MVC / Tutorials / Chapter 3. Getting Started with EF using MVC / Implementing the Repository and Unit of Work Patterns in an ASP.NET MVC Application (9 of 10) The Contoso University sample web application demonstrates how to create ASP.NET MVC applications using the Entity Framework. The sample application is a website for a fictional Contoso University.