Contents tagged with Entity Framework
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ASP.NET Articles added in the month of January 2014
In case you missed earlier updates, here is a list of recently added articles:
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Using Complex Types in Entity Framework
A database table represents your application data in row-column format. Although in many cases this row-column structure can be mapped directly to entities, at times you may need to reorganize the same. Consider, for example, the Customers table of Northwind database. The Customers table has Address, City, Region, Country and PostalCode columns representing the address of the company. The entity that represents this table might not be as "flat" as the table. For example, you may wish to have a property - Location - that is of class type and has properties such as Street, City, Region and PostalCode. Luckily, entity framework allows you to do so quite easily. The remainder of this article explains how.
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Executing Raw SQL Queries using Entity Framework
While working with Entity Framework developers mostly use LINQ to Entities to query database. However, at times you may need to execute raw queries against the database. A common scenario is when you wish to generate an SQL query dynamically. Luckily, EF allows you to execute raw queries easily. This article explains how that can be done.
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Dealing With Optimistic Concurrency in Entity Framework
When you update a database record with the entity values, the database values are overwritten by the entity values (default behavior). In a real world situation it is quite possible that database values might have got changed after selecting them for modification. In such cases, your update operation might be overwriting changes made by someone else. That is why it becomes important to detect if concurrency violation has occurred. You can then take some corrective action or at least inform the user about such a violation. To that end this article shows how to detect concurrency violation in EF and also the possible ways to deal with the situation.
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Two book reviews
I recently reviewed two books - Programming Microsoft ASP.NET MVC, 2nd Edition and Programming Entity Framework - Code First. Here are the links to the complete reviews:
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Introduction to Entity Framework Code First
Entity Framework (EF) allows you to program against a model instead of dealing with a database directly. In EF 4.0 (that ships with .NET 4.0) you typically design a model from an existing database visually, using a designer provided for that purpose. EF 4.1 builds on top of what EF 4.0 provided and allows you to create models directly at code level. That means instead of creating any database and then using a designer to define models, you create plain .NET classes and then use EF 4.1 techniques to make them EF models. This approach is referred as Code First because you focus on the source code of the model classes first. Once the models are ready Code First can also generate database tables out of those model classes. In this tutorial you will learn the basics of developing an application using Entity Framework Code First.