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Sorting, Filtering, and Paging with the Entity Framework in an ASP.NET MVC Application (3 of 10)

By Tom Dykstra|

Download Completed Project

The Contoso University sample web application demonstrates how to create ASP.NET MVC 4 applications using the Entity Framework 5 Code First and Visual Studio 2012. For information about the tutorial series, see the first tutorial in the series. You can start the tutorial series from the beginning or download a starter project for this chapter and start here.

If you run into a problem you can’t resolve, download the completed chapter and try to reproduce your problem. You can generally find the solution to the problem by comparing your code to the completed code. For some common errors and how to solve them, see Errors and Workarounds.

In the previous tutorial you implemented a set of web pages for basic CRUD operations for Student entities. In this tutorial you'll add sorting, filtering, and paging functionality to the Students Index page. You'll also create a page that does simple grouping.

The following illustration shows what the page will look like when you're done. The column headings are links that the user can click to sort by that column. Clicking a column heading repeatedly toggles between ascending and descending sort order.

Students_Index_page_with_paging

Add Column Sort Links to the Students Index Page

To add sorting to the Student Index page, you'll change the Index method of the Student controller and add code to the Student Index view.

Add Sorting Functionality to the Index Method

In Controllers\StudentController.cs, replace the Index method with the following code:

public ActionResult Index(string sortOrder)
{
   ViewBag.NameSortParm = String.IsNullOrEmpty(sortOrder) ? "Name_desc" : "";
   ViewBag.DateSortParm = sortOrder == "Date" ? "Date_desc" : "Date";
   var students = from s in db.Students
                  select s;
   switch (sortOrder)
   {
      case "Name_desc":
         students = students.OrderByDescending(s => s.LastName);
         break;
      case "Date":
         students = students.OrderBy(s => s.EnrollmentDate);
         break;
      case "Date_desc":
         students = students.OrderByDescending(s => s.EnrollmentDate);
         break;
      default:
         students = students.OrderBy(s => s.LastName);
         break;
   }
   return View(students.ToList());
}

This code receives a sortOrder parameter from the query string in the URL. The query string value is provided by ASP.NET MVC as a parameter to the action method. The parameter will be a string that's either "Name" or "Date", optionally followed by an underscore and the string "desc" to specify descending order. The default sort order is ascending.

The first time the Index page is requested, there's no query string. The students are displayed in ascending order by LastName, which is the default as established by the fall-through case in the switch statement. When the user clicks a column heading hyperlink, the appropriate sortOrder value is provided in the query string.

The two ViewBag variables are used so that the view can configure the column heading hyperlinks with the appropriate query string values:

ViewBag.NameSortParm = String.IsNullOrEmpty(sortOrder) ? "Name_desc" : "";
ViewBag.DateSortParm = sortOrder == "Date" ? "Date_desc" : "Date";

These are ternary statements. The first one specifies that if the sortOrder parameter is null or empty, ViewBag.NameSortParm should be set to "name_desc"; otherwise, it should be set to an empty string. These two statements enable the view to set the column heading hyperlinks as follows:

Current sort order Last Name Hyperlink Date Hyperlink
Last Name ascending descending ascending
Last Name descending ascending ascending
Date ascending ascending descending
Date descending ascending ascending

The method uses LINQ to Entities to specify the column to sort by. The code creates an IQueryable variable before the switch statement, modifies it in the switch statement, and calls the ToList method after the switch statement. When you create and modify IQueryable variables, no query is sent to the database. The query is not executed until you convert the IQueryable object into a collection by calling a method such as ToList. Therefore, this code results in a single query that is not executed until the return View statement.

Add Column Heading Hyperlinks to the Student Index View

In Views\Student\Index.cshtml, replace the <tr> and <th> elements for the heading row with the highlighted code:

<p>
    @Html.ActionLink("Create New", "Create")
</p>
<table>
    <tr>
        <th>
            @Html.ActionLink("Last Name", "Index", new { sortOrder = ViewBag.NameSortParm })
        </th>
        <th>First Name
        </th>
        <th>
            @Html.ActionLink("Enrollment Date", "Index", new { sortOrder = ViewBag.DateSortParm })
        </th>
        <th></th>
    </tr>

    @foreach (var item in Model)
    {

This code uses the information in the ViewBag properties to set up hyperlinks with the appropriate query string values.

Run the page and click the Last Name and Enrollment Date column headings to verify that sorting works.

Students_Index_page_with_sort_hyperlinks

After you click the Last Name heading, students are displayed in descending last name order.

Add a Search Box to the Students Index Page

To add filtering to the Students Index page, you'll add a text box and a submit button to the view and make corresponding changes in the Index method. The text box will let you enter a string to search for in the first name and last name fields.

Add Filtering Functionality to the Index Method

In Controllers\StudentController.cs, replace the Index method with the following code (the changes are highlighted):

public ViewResult Index(string sortOrder, string searchString)
{
    ViewBag.NameSortParm = String.IsNullOrEmpty(sortOrder) ? "name_desc" : "";
    ViewBag.DateSortParm = sortOrder == "Date" ? "date_desc" : "Date";
    var students = from s in db.Students
                   select s;
    if (!String.IsNullOrEmpty(searchString))
    {
        students = students.Where(s => s.LastName.ToUpper().Contains(searchString.ToUpper())
                               || s.FirstMidName.ToUpper().Contains(searchString.ToUpper()));
    }
    switch (sortOrder)
    {
        case "name_desc":
            students = students.OrderByDescending(s => s.LastName);
            break;
        case "Date":
            students = students.OrderBy(s => s.EnrollmentDate);
            break;
        case "date_desc":
            students = students.OrderByDescending(s => s.EnrollmentDate);
            break;
        default:
            students = students.OrderBy(s => s.LastName);
            break;
    }

    return View(students.ToList());
}

You've added a searchString parameter to the Index method. You've also added  to the LINQ statement a where clausethat selects only students whose first name or last name contains the search string. The search string value is received from a text box that you'll add to the Index view. The statement that adds the where clause is executed only if there's a value to search for.

Note In many cases you can call the same method either on an Entity Framework entity set or as an extension method on an in-memory collection. The results are normally the same but in some cases may be different.  For example, the .NET Framework implementation of the Contains method returns all rows when you pass an empty string to it, but the Entity Framework provider for SQL Server Compact 4.0 returns zero rows for empty strings. Therefore the code in the example (putting the Where statement inside an if statement) makes sure that you get the same results for all versions of SQL Server. Also, the .NET Framework implementation of the Contains method performs a case-sensitive comparison by default, but Entity Framework SQL Server providers perform case-insensitive comparisons by default. Therefore, calling the ToUpper method to make the test explicitly case-insensitive ensures that results do not change when you change the code later to use a repository, which will return an IEnumerable collection instead of an IQueryable object. (When you call the Contains method on an IEnumerable collection, you get the .NET Framework implementation; when you call it on an IQueryable object, you get the database provider implementation.)

Add a Search Box to the Student Index View

In Views\Student\Index.cshtml, add the highlighted code immediately before the opening table tag in order to create a caption, a text box, and a Search button.

<p>
    @Html.ActionLink("Create New", "Create")
</p>

@using (Html.BeginForm())
{
    <p>
        Find by name: @Html.TextBox("SearchString")  
        <input type="submit" value="Search" /></p>
}

<table>
    <tr>
 

Run the page, enter a search string, and click Search to verify that filtering is working.

Students_Index_page_with_search_box

Notice the URL doesn't contain the "an" search string, which means that if you bookmark this page, you won't get the filtered list when you use the bookmark. You'll change the Search button to use query strings for filter criteria later in the tutorial.

Add Paging to the Students Index Page

To add paging to the Students Index page, you'll start by installing the PagedList.Mvc NuGet package. Then you'll make additional changes in the Index method and add paging links to the Index view. PagedList.Mvc is one of many good paging and sorting packages for ASP.NET MVC, and its use here is intended only as an example, not as a recommendation for it over other options. The following illustration shows the paging links.

Students_index_page_with_paging

Install the PagedList.MVC NuGet Package

The NuGet PagedList.Mvc package automatically installs the PagedList package as a dependency. The PagedList package installs a PagedList collection type and extension methods for IQueryable and IEnumerable collections. The extension methods create a single page of data in a PagedList collection out of your IQueryable or IEnumerable, and the PagedList collection provides several properties and methods that facilitate paging. The PagedList.Mvc package installs a paging helper that displays the paging buttons.

From the Tools menu, select Library Package Manager and then Manage NuGet Packages for Solution.

In the Manage NuGet Packages dialog box, click the Online tab on the left and then enter "paged" in the search box. When you see the PagedList.Mvc package, click Install.

In the Select Projects box, click OK.

Add Paging Functionality to the Index Method

In Controllers\StudentController.cs, add a using statement for the PagedList namespace:

using PagedList;

Replace the Index method with the following code:

public ViewResult Index(string sortOrder, string currentFilter, string searchString, int? page)
{
   ViewBag.CurrentSort = sortOrder;
   ViewBag.NameSortParm = String.IsNullOrEmpty(sortOrder) ? "name_desc" : "";
   ViewBag.DateSortParm = sortOrder == "Date" ? "date_desc" : "Date";

   if (searchString != null)
   {
      page = 1;
   }
   else
   {
      searchString = currentFilter;
   }

   ViewBag.CurrentFilter = searchString;

   var students = from s in db.Students
                  select s;
   if (!String.IsNullOrEmpty(searchString))
   {
      students = students.Where(s => s.LastName.ToUpper().Contains(searchString.ToUpper())
                             || s.FirstMidName.ToUpper().Contains(searchString.ToUpper()));
   }
   switch (sortOrder)
   {
      case "name_desc":
         students = students.OrderByDescending(s => s.LastName);
         break;
      case "Date":
         students = students.OrderBy(s => s.EnrollmentDate);
         break;
      case "date_desc":
         students = students.OrderByDescending(s => s.EnrollmentDate);
         break;
      default:  // Name ascending 
         students = students.OrderBy(s => s.LastName);
         break;
   }

   int pageSize = 3;
   int pageNumber = (page ?? 1);
   return View(students.ToPagedList(pageNumber, pageSize));
}

This code adds a page parameter, a current sort order parameter, and a current filter parameter to the method signature, as shown here:

public ActionResult Index(string sortOrder, string currentFilter, string searchString, int? page)

The first time the page is displayed, or if the user hasn't clicked a paging or sorting link, all the parameters will be null.  If a paging link is clicked, the page variable will contain the page number to display.

A ViewBag property provides the view with the current sort order, because this must be included in the paging links in order to keep the sort order the same while paging:

ViewBag.CurrentSort = sortOrder;

Another property, ViewBag.CurrentFilter, provides the view with the current filter string. This value must be included in the paging links in order to maintain the filter settings during paging, and it must be restored to the text box when the page is redisplayed. If the search string is changed during paging, the page has to be reset to 1, because the new filter can result in different data to display. The search string is changed when a value is entered in the text box and the submit button is pressed. In that case, the searchString parameter is not null.

if (searchString != null)
        page = 1;
    else
        searchString = currentFilter;

At the end of the method, the ToPagedList extension method on the students IQueryable object converts the student query to a single page of students in a collection type that supports paging. That single page of students is then passed to the view:

int pageSize = 3;
int pageNumber = (page ?? 1);
return View(students.ToPagedList(pageNumber, pageSize));

The ToPagedList method takes a page number. The two question marks represent the null-coalescing operator. The null-coalescing operator defines a default value for a nullable type; the expression (page ?? 1) means return the value of page if it has a value, or return 1 if page is null.

Add Paging Links to the Student Index View

In Views\Student\Index.cshtml, replace the existing code with the following code:

@model PagedList.IPagedList<ContosoUniversity.Models.Student>
@using PagedList.Mvc; 
<link href="~/Content/PagedList.css" rel="stylesheet" type="text/css" />

@{
    ViewBag.Title = "Students";
}

<h2>Students</h2>

<p>
    @Html.ActionLink("Create New", "Create")
</p>
@using (Html.BeginForm("Index", "Student", FormMethod.Get))
{
    <p>
        Find by name: @Html.TextBox("SearchString", ViewBag.CurrentFilter as string)  
        <input type="submit" value="Search" />
    </p>
}
<table>
<tr>
    <th></th>
    <th>
        @Html.ActionLink("Last Name", "Index", new { sortOrder=ViewBag.NameSortParm, currentFilter=ViewBag.CurrentFilter })
    </th>
    <th>
        First Name
    </th>
    <th>
        @Html.ActionLink("Enrollment Date", "Index", new { sortOrder = ViewBag.DateSortParm, currentFilter = ViewBag.CurrentFilter })
    </th>
</tr>

@foreach (var item in Model) {
    <tr>
        <td>
            @Html.ActionLink("Edit", "Edit", new { id=item.StudentID }) |
            @Html.ActionLink("Details", "Details", new { id=item.StudentID }) |
            @Html.ActionLink("Delete", "Delete", new { id=item.StudentID })
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.LastName)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.FirstMidName)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.EnrollmentDate)
        </td>
    </tr>
}

</table>
<br />
Page @(Model.PageCount < Model.PageNumber ? 0 : Model.PageNumber) of @Model.PageCount

@Html.PagedListPager( Model, page => Url.Action("Index", new { page, sortOrder = ViewBag.CurrentSort, currentFilter=ViewBag.CurrentFilter }) )

The @model statement at the top of the page specifies that the view now gets a PagedList object instead of a List object.

The  using statement for PagedList.Mvc gives access to the MVC helper for the paging buttons. 

The code uses an overload of BeginForm that allows it to specify FormMethod.Get.

@using (Html.BeginForm("Index", "Student", FormMethod.Get))
{
    <p>
        Find by name: @Html.TextBox("SearchString", ViewBag.CurrentFilter as string)  
        <input type="submit" value="Search" />
    </p>
} 

 The default BeginForm submits form data with a POST, which means that parameters are passed in the HTTP message body and not in the URL as query strings. When you specify HTTP GET, the form data is passed in the URL as query strings, which enables users to bookmark the URL. The W3C guidelines for the use of HTTP GET specify that you should use GET when the action does not result in an update.

The text box is initialized with the current search string so when you click a new page you can see the current search string.

 Find by name: @Html.TextBox("SearchString", ViewBag.CurrentFilter as string)  

The column header links use the query string to pass the current search string to the controller so that the user can sort within filter results:

 @Html.ActionLink("Last Name", "Index", new { sortOrder=ViewBag.NameSortParm, currentFilter=ViewBag.CurrentFilter })

The current page and total number of pages are displayed.

Page @(Model.PageCount < Model.PageNumber ? 0 : Model.PageNumber) of @Model.PageCount

If there are no pages to display, "Page 0 of 0" is shown. (In that case the page number is greater than the page count because Model.PageNumber is 1, and Model.PageCount is 0.)

The paging buttons are displayed by the PagedListPager helper:

@Html.PagedListPager( Model, page => Url.Action("Index", new { page }) )

The PagedListPager helper provides a number of options that you can customize, including URLs and styling.  For more information, see TroyGoode  / PagedList on the GitHub site.

Run the page.

Students_index_page_with_paging

Click the paging links in different sort orders to make sure paging works. Then enter a search string and try paging again to verify that paging also works correctly with sorting and filtering.

Create an About Page That Shows Student Statistics

For the Contoso University website's About page, you'll display how many students have enrolled for each enrollment date. This requires grouping and simple calculations on the groups. To accomplish this, you'll do the following:

  • Create a view model class for the data that you need to pass to the view.
  • Modify the About method in the Home controller.
  • Modify the About view.

Create the View Model

Create a ViewModels folder. In that folder, add a class file EnrollmentDateGroup.cs and replace the existing code with the following code:

using System;
using System.ComponentModel.DataAnnotations;

namespace ContosoUniversity.ViewModels
{
    public class EnrollmentDateGroup
    {
        [DataType(DataType.Date)]
        public DateTime? EnrollmentDate { get; set; }

        public int StudentCount { get; set; }
    }
}

Modify the Home Controller

In HomeController.cs, add the following using statements at the top of the file:

using ContosoUniversity.DAL;
using ContosoUniversity.ViewModels;

Add a class variable for the database context immediately after the opening curly brace for the class:

    public class HomeController : Controller
    {
        private SchoolContext db = new SchoolContext();

Replace the About method with the following code:

public ActionResult About()
{
    var data = from student in db.Students
               group student by student.EnrollmentDate into dateGroup
               select new EnrollmentDateGroup()
               {
                   EnrollmentDate = dateGroup.Key,
                   StudentCount = dateGroup.Count()
               };
    return View(data);
}

The LINQ statement groups the student entities by enrollment date, calculates the number of entities in each group, and stores the results in a collection of EnrollmentDateGroup view model objects.

Add a Dispose method:

protected override void Dispose(bool disposing)
{
    db.Dispose();
    base.Dispose(disposing);
}

Modify the About View

Replace the code in the Views\Home\About.cshtml file with the following code:

@model IEnumerable<ContosoUniversity.ViewModels.EnrollmentDateGroup>
           
@{
    ViewBag.Title = "Student Body Statistics";
}

<h2>Student Body Statistics</h2>

<table>
    <tr>
        <th>
            Enrollment Date
        </th>
        <th>
            Students
        </th>
    </tr>

@foreach (var item in Model) {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.EnrollmentDate)
        </td>
        <td>
            @item.StudentCount
        </td>
    </tr>
}
</table>

Run the app and click the About link. The count of students for each enrollment date is displayed in a table.

About_page

Optional: Deploy the app to Windows Azure

So far your application has been running locally in IIS Express on your development computer.  To make it available for other people to use over the Internet, you have to deploy it to a web hosting provider. In this optional section of the tutorial you'll deploy it to a Windows Azure Web Site. 

Using Code First Migrations to Deploy the Database

To deploy the database you'll use Code First Migrations.  When you create the publish profile that you use to configure settings for deploying from Visual Studio, you'll select a check box that is labeled Execute Code First Migrations (runs on application start).  This setting causes the deployment process to automatically configure the application Web.config file on the destination server so that Code First uses the MigrateDatabaseToLatestVersion initializer class.

Visual Studio does not do anything with the database during the deployment process. When the deployed application accesses the database for the first time after deployment, Code First automatically creates the database or updates the database schema to the latest version. If the application implements a Migrations Seed method, the method runs after the database is created or the schema is updated.

Your Migrations Seed method inserts test data. If you were deploying to a production environment, you would have to change the Seed method so that it only inserts data that you want to be inserted into your production database. For example, in your current data model you might want to have real courses but fictional students in the development database. You can write a Seed method to load both in development, and then comment out the fictional students before you deploy to production. Or you can write a Seed method to load only courses, and enter the fictional students in the test database manually by using the application's UI.

Get a Windows Azure account

You'll need a Windows Azure account. If you don't already have one, you can create a free trial account in just a couple of minutes. For details, see Windows Azure Free Trial.

Create a web site and a SQL database in Windows Azure

Your Windows Azure Web Site will run in a shared hosting environment, which means it runs on virtual machines (VMs) that are shared with other Windows Azure clients. A shared hosting environment is a low-cost way to get started in the cloud. Later, if your web traffic increases, the application can scale to meet the need by running on dedicated VMs. If you need a more complex architecture, you can migrate to a Windows Azure Cloud Service. Cloud services run on dedicated VMs that you can configure according to your needs.

Windows Azure SQL Database is a cloud-based relational database service that is built on SQL Server technologies. Tools and applications that work with SQL Server also work with SQL Database.

  1. In the Windows Azure Management Portal, click Web Sites in the left tab, and then click New.

    New button in Management Portal

  2. Click CUSTOM CREATE.

    Create with Database link in Management Portal

    The New Web Site - Custom Create wizard opens.
  3. In the New Web Site step of the wizard, enter a string in the URL box to use as the unique URL for your application. The complete URL will consist of what you enter here plus the suffix that you see next to the text box. The illustration shows "ConU", but that URL is probably taken so you will have to choose a different one.

    Create with Database link in Management Portal

  4. In the Region drop-down list, choose a region close to you. This setting specifies which data center your web site will run in.
  5. In the Database drop-down list, choose Create a free 20 MB SQL database.

  6. In the DB CONNECTION STRING NAME, enter SchoolContext.


  7. Click the arrow that points to the right at the bottom of the box. The wizard advances to the Database Settings step.
  8. In the Name box, enter ContosoUniversityDB.
  9. In the Server box, select New SQL Database server. Alternatively, if you previously created a server, you can select that server from the drop-down list.
  10. Enter an administrator LOGIN NAME and PASSWORD. If you selected New SQL Database server you aren't entering an existing name and password here, you're entering a new name and password that you're defining now to use later when you access the database. If you selected a server that you created previously, you’ll enter credentials for that server. For this tutorial, you won't select the Advanced  check box. The Advanced  options enable you to set  the database collation.
  11. Choose the same Region that you chose for the web site.

  12. Click the check mark at the bottom right of the box to indicate that you're finished.

    Database Settings step of New Web Site - Create with Database wizard


    The following image shows using an existing SQL Server and Login.

    Database Settings step of New Web Site - Create with Database wizard

    The Management Portal returns to the Web Sites page, and the Status column shows that the site is being created. After a while (typically less than a minute), the Status column shows that the site was successfully created. In the navigation bar at the left, the number of sites you have in your account appears next to the Web Sites icon, and the number of databases appears next to the SQL Databases icon.

 

Deploy the application to Windows Azure

  1. In Visual Studio, right-click the project in Solution Explorer and select Publish from the context menu.

    Publish in project context menu

  2. In the Profile tab of the Publish Web wizard, click Import.

    Import publish settings

  3. If you have not previously added your Windows Azure subscription in Visual Studio, perform the following steps. In these steps you add your subscription so that the drop-down list under Import from a Windows Azure web site will include your web site.

    a. In the Import Publish Profile dialog box, click Import from a Windows Azure web site, and then click Add Windows Azure subscription.

    add Windows Azure subscription

    b. In the Import Windows Azure Subscriptions dialog box, click Download subscription file.

    download subscription file

    c. In your browser window, save the .publishsettings file.

    download .publishsettings file

    Security Note: The publishsettings file contains your credentials (unencoded) that are used to administer your Windows Azure subscriptions and services. The security best practice for this file is to store it temporarily outside your source directories (for example in the Libraries\Documents folder), and then delete it once the import has completed. A malicious user who gains access to the .publishsettings file can edit, create, and delete your Windows Azure services.

    d. In the Import Windows Azure Subscriptions dialog box, click Browse and navigate to the .publishsettings file.

    download sub

    e. Click Import.

    import

  4. In the Import Publish Profile dialog box, select Import from a Windows Azure web site, select your web site from the drop-down list, and then click OK.

    Import Publish Profile

  5. In the Connection tab, click Validate Connection to make sure that the settings are correct.

    Validate connection

  6. When the connection has been validated, a green check mark is shown next to the Validate Connection button. Click Next.

    Successfully validated connection

  7. Open the Remote connection string drop-down list under SchoolContext and select the connection string for the database you created.
  8. Select Execute Code First Migrations (runs on application start).

  9. Uncheck Use this connection string at runtime for the UserContext (DefaultConnection), since this application is not using the membership database.

    Settings tab

  10. Click Next.
  11. In the Preview tab, click Start Preview.

    StartPreview button in the Preview tab

    The tab displays a list of the files that will be copied to the server. Displaying the preview isn't required to publish the application but is a useful function to be aware of. In this case, you don't need to do anything with the list of files that is displayed. The next time you deploy this application, only the files that have changed will be in this list.

    StartPreview file output

  12. Click Publish.
    Visual Studio begins the process of copying the files to the Windows Azure server.
  13. The Output window shows what deployment actions were taken and reports successful completion of the deployment.

    Output window reporting successful deployment

  14. Upon successful deployment, the default browser automatically opens to the URL of the deployed web site.
    The application you created is now running in the cloud. Click the Students tab.

    Students_index_page_with_paging

At this point your SchoolContext database has been created in the Windows Azure SQL Database because you selected Execute Code First Migrations (runs on app start). The Web.config file in the deployed web site has been changed so that the MigrateDatabaseToLatestVersion initializer would run the first time your code reads or writes data in the database (which happened when you selected the Students tab):

The deployment process also created a new connection string (SchoolContext_DatabasePublish) for Code First Migrations to use for updating the database schema and seeding the database.

Database_Publish connection string

The DefaultConnection connection string is for the membership database (which we are not using in this tutorial). The SchoolContext connection string is for the ContosoUniversity database.

You can find the deployed version of the Web.config file on your own computer in ContosoUniversity\obj\Release\Package\PackageTmp\Web.config. You can access the deployed Web.config file itself by using FTP. For instructions, see ASP.NET Web Deployment using Visual Studio: Deploying a Code Update. Follow the instructions that start with "To use an FTP tool, you need three things: the FTP URL, the user name, and the password."

Note: The web app doesn't implement security, so anyone who finds the URL can change the data. For instructions on how to secure the web site, see Deploy a Secure ASP.NET MVC app with Membership, OAuth, and SQL Database to a Windows Azure Web Site. You can prevent other people from using the site by using the Windows Azure Management Portal or Server Explorer in Visual Studio to stop the site.

Code First Initializers

In the deployment section you saw the MigrateDatabaseToLatestVersion initializer being used. Code First also provides other initializers that you can use, including CreateDatabaseIfNotExists (the default),  DropCreateDatabaseIfModelChanges and DropCreateDatabaseAlways. The DropCreateAlways initializer can be useful for setting up conditions for unit tests. You can also write your own initializers, and you can call an initializer explicitly if you don't want to wait until the application reads from or writes to the database. For a comprehensive explanation of initializers, see chapter 6 of the book Programming Entity Framework: Code First by Julie Lerman and Rowan Miller.

Summary

In this tutorial you've seen how to create a data model and implement basic CRUD, sorting, filtering, paging, and grouping functionality. In the next tutorial you'll begin looking at more advanced topics by expanding the data model.

Links to other Entity Framework resources can be found in the ASP.NET Data Access Content Map.

Author Information

Tom Dykstra

Tom Dykstra – Tom Dykstra is a Senior Programming Writer on Microsoft's Web Platform & Tools Content Team...