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4.1 KiB
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77 lines
4.1 KiB
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---
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title: "Adding a Model | Microsoft Docs"
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author: Rick-Anderson
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description: "Note: An updated version of this tutorial is available here that uses ASP.NET MVC 5 and Visual Studio 2013. It's more secure, much simpler to follow and demo..."
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ms.author: aspnetcontent
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manager: wpickett
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ms.date: 08/28/2012
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ms.topic: article
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ms.assetid: 53db72da-e0b9-44d9-b60b-6e6988c00b28
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ms.technology: dotnet-mvc
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ms.prod: .net-framework
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msc.legacyurl: /mvc/overview/older-versions/getting-started-with-aspnet-mvc4/adding-a-model
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msc.type: authoredcontent
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---
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Adding a Model
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====================
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by [Rick Anderson](https://github.com/Rick-Anderson)
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> > [!NOTE]
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> > An updated version of this tutorial is available [here](../../getting-started/introduction/getting-started.md) that uses ASP.NET MVC 5 and Visual Studio 2013. It's more secure, much simpler to follow and demonstrates more features.
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In this section you'll add some classes for managing movies in a database. These classes will be the "model" part of the ASP.NET MVC application.
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You'll use a .NET Framework data-access technology known as the [Entity Framework](https://msdn.microsoft.com/en-us/library/bb399572(VS.110).aspx) to define and work with these model classes. The Entity Framework (often referred to as EF) supports a development paradigm called *Code First*. Code First allows you to create model objects by writing simple classes. (These are also known as POCO classes, from "plain-old CLR objects.") You can then have the database created on the fly from your classes, which enables a very clean and rapid development workflow.
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## Adding Model Classes
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In **Solution Explorer**, right click the *Models* folder, select **Add**, and then select **Class**.
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Enter the *class* name "Movie".
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Add the following five properties to the `Movie` class:
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[!code-csharp[Main](adding-a-model/samples/sample1.cs)]
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We'll use the `Movie` class to represent movies in a database. Each instance of a `Movie` object will correspond to a row within a database table, and each property of the `Movie` class will map to a column in the table.
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In the same file, add the following `MovieDBContext` class:
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[!code-csharp[Main](adding-a-model/samples/sample2.cs)]
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The `MovieDBContext` class represents the Entity Framework movie database context, which handles fetching, storing, and updating `Movie` class instances in a database. The `MovieDBContext` derives from the `DbContext` base class provided by the Entity Framework.
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In order to be able to reference `DbContext` and `DbSet`, you need to add the following `using` statement at the top of the file:
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[!code-csharp[Main](adding-a-model/samples/sample3.cs)]
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The complete *Movie.cs* file is shown below. (Several using statements that are not needed have been removed.)
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[!code-csharp[Main](adding-a-model/samples/sample4.cs)]
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## Creating a Connection String and Working with SQL Server LocalDB
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The `MovieDBContext` class you created handles the task of connecting to the database and mapping `Movie` objects to database records. One question you might ask, though, is how to specify which database it will connect to. You'll do that by adding connection information in the *Web.config* file of the application.
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Open the application root *Web.config* file. (Not the *Web.config* file in the *Views* folder.) Open the *Web.config* file outlined in red.
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Add the following connection string to the `<connectionStrings>` element in the *Web.config* file.
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[!code-xml[Main](adding-a-model/samples/sample5.xml)]
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The following example shows a portion of the *Web.config* file with the new connection string added:
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[!code-xml[Main](adding-a-model/samples/sample6.xml?highlight=6-9)]
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This small amount of code and XML is everything you need to write in order to represent and store the movie data in a database.
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Next, you'll build a new `MoviesController` class that you can use to display the movie data and allow users to create new movie listings.
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>[!div class="step-by-step"]
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[Previous](adding-a-view.md)
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[Next](accessing-your-models-data-from-a-controller.md)
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