element, type this:
@TwitterGoodies.
The @ character is the same character you've been using to mark Razor code. TwitterGoodies is
the helper object that you're working with.
As soon as you type the period (.), WebMatrix displays a list of methods (functions) that the
TwitterGoodies helper makes available:
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This feature is known as IntelliSense. It helps you code by providing context-appropriate choices.
IntelliSense works with HTML, CSS, ASP.NET code, JavaScript, and other languages that are
supported in WebMatrix. It's another feature that makes it easier to develop web pages in
WebMatrix.
Press S on the keyboard, and you see that IntelliSense finds the Search method:
Press Tab. IntelliSense inserts the selected method (Search) for you. Type an open parenthesis ( (
), then the string "webmatrix" in quotation marks, then a closing parenthesis ( ) ). When you're
done, the line looks like this:
@TwitterGoodies.Search("webmatrix")
The Search method finds tweets that contain the string that you specify — in this case, it will look
for tweets that mention "webmatrix". (Either in text or in hashtags.)
Run the page. You see a Twitter feed. (It might take a few moments for the feed to start
populating.)
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To get an idea of what the helper is doing for you, view the source of the page in the
browser.Along with the HTML that you had in your page, you see a block of JavaScript code that
looks roughly like the following block. (It might be all on one line or otherwise compressed.)
This is code that the helper rendered into the page at the place where you had
@TwitterGoodies.Search. (There's also some markup that's not shown here.) The helper took the
information you provided and generated the code that talks directly to Twitter in order to get
back the Twitter feed that you see. If you know the Twitter programming interface (API), you can
create this code yourself. But because the helper can do it for you, you don't have to know the
details of how to communicate with Twitter. And even if you are familiar with the Twitter API, it's
a lot easier to include the TwitterGoodies helper on the page and let it do the work.
Return to the page. At the bottom, inside the element, add the following code. Substitute
your own Twitter account name if you have one.
Again, you could have written this code yourself, but the helper makes it much easier.
Server-Side (Razor) and Client-Side (JavaScript) Programming
How does Razor code in an ASP.NET Web Pages relate to JavaScript code that runs in the
browser? If you've got experience with JavaScript, you might realize as you work with these
tutorials that many of the tasks could also be done in JavaScript. That's true, especially with the
simple examples you've seen so far.
A .cshtml page can contain both Razor code and JavaScript code. The traditional division of labor
has been that server code handled tasks that it made sense to run on the server. This included
accessing resources like a shared database and performing various types of business logic. In
contrast, client code has typically been used to create a rich user experience. Pop-up calendars,
sliders, animations, and many other UI effects are created by client code, and can all be done
easily using JavaScript libraries (especially jQuery).
These days the distinction has blurred a little because client code libraries now let you
communicate with the server in ways that formerly could only be done in server code. In general,
though, it's still useful to think of server code (Razor and C#) as being for back-end work and client
code (JavaScript) as useful for UI. In subsequent tutorial sets you'll learn how to integrate
JavaScript into a .cshtml page for just this purpose, namely to create a lively user experience.
Coming Up Next
To keep this tutorial short, we had to focus on only a few basics. Naturally, there's a lot more to
Razor and C#. You'll learn more as you go through these tutorials. If you're interested in learning
Introducing ASP.NET Web Pages 2
Tutorial 2: Programming Basics
37
more about the programming aspects of Razor and C# right now, you can read a more thorough
introduction here:Introduction to ASP.NET Web Programming Using the Razor Syntax.
The next tutorial introduces you to working with a database. In that tutorial, you'll begin creating
the sample application that lets you list your favorite movies.
Additional Resources
• Complete Listing for Test Razor Page
• Complete Listing for TestRazorPart2 Page
• Complete Listing for TwitterTest Page
•
Introduction to ASP.NET Web Programming Using the Razor Syntax
Introducing ASP.NET Web Pages 2
Tutorial 2: Programming Basics
38
Tutorial 3: Displaying Data
This tutorial shows you how to create a database in WebMatrix and how to display database data
in a page when you use ASP.NET Web Pages (Razor).
What you'll learn:
• How to use WebMatrix tools to create a database and database tables.
• How to use WebMatrix tools to add data to a database.
• How to display data from the database on a page.
• How to run SQL commands in ASP.NET Web Pages.
• How to customize the WebGrid helper to change the data display and to add paging and
sorting.
Features/technologies discussed:
• WebMatrix database tools.
•
WebGrid helper.
What You'll Build
In the previous tutorial, you were introduced to ASP.NET Web Pages (.cshtml files), to the basics
of Razor syntax, and to helpers. In this tutorial, you'll begin creating the actual web application
that you'll use for the rest of the series. The app is a simple movie application that lets you view,
add, change, and delete information about movies.
When you're done with this tutorial, you'll be able to view a movie listing that looks like this page:
But to begin, you have to create a database.
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A Very Brief Introduction to Databases
This tutorial will provide only the briefest introduction to databases. If you have database
experience, you can skip this short section.
A database contains one or more tables that contain information — for example, tables for
customers, orders, and vendors,or for students, teachers, classes, and grades. Structurally, a
database table is like a spreadsheet. Imagine a typical address book. For each entry in the address
book (that is, for each person) you have several pieces of information such as first name, last
name, address, email address, and phone number.
(Rows are sometimes referred to as records, and columns are sometimes referred to as fields.)
For most database tables, the table has to have a column that contains a unique value, like a
customer number, account number, and so on. This value is known as the table's primary key, and
you use it to identify each row in the table. In the example, the ID column is the primary key for
the address book shown in the previous example.
Much of the work you do in web applications consists of reading information out of the database
and displaying it on a page. You'll also often gather information from users and add it to a
database, or you'll modify records that are already in the database. (We'll cover all of these
operations in the course of this tutorial set.)
Database work can be enormously complex and can require specialized knowledge. For this
tutorial set, though, you have to understand only basic concepts, which will all be explained as
you go.
Creating a Database
WebMatrix includes tools that make it easy to create (or define) a database and to create tables in
the database. For this tutorial set, you'll create a database that has only one table in it — Movies.
Open WebMatrix if you haven't already done so, and open the WebPagesMovies site that you
created in the previous tutorial.
In the left pane, click the Database workspace.
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The ribbon changes to show database-related tasks. In the ribbon, click New Database.
WebMatrix creates a database (an .sdf file) that has the same name as your site —
WebPagesMovies.sdf. (You won't do this here, but you can rename the file to anything you like, as
long as it has an .sdf extension.)
Creating a Table
In the ribbon, click New Table. WebMatrix opens the table designer in a new tab. (If the New
Table option isn't available, make sure that the new database is selected in the tree view on the
left.)
In the text box at the top (where the watermark says "Enter table name"), enter "Movies".
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The pane underneath the table name is where you define individual columns. For the Movies
table in this tutorial, you'll create only a few columns: ID, Title, Genre, and Year.
In the Name box, enter "ID". Entering a value here activates all the controls for the new column.
Tab to the Data Type list and choose int. This value specifies that the ID column will contain
integer (number) data.
Note We won't call it out any more here (much), but you can use standard Windows
keyboard gestures to navigate in this grid. For example, you can tab between fields, you
can just start typing in order to select an item in a list, and so on.
Tab past the Default Value box (that is, leave it blank). Tab to the Is Primary Key check box and
select it. This option tells the database that the ID column will contain the data that identifies
individual rows. (That is, each row will have a unique value in the ID column that you can use to
find that row.)
Choose the Is Identity option. This option tells the database that it should automatically generate
the next sequential number for each new row. (The Is Identity option works only if you've also
selected the Is Primary Key option.)
Click in the next grid row, or press Tab twice to finish the current row. Either gesture saves the
current row and starts the next one. Notice that the Default Value column now says Null. (Null is
the default value for the default value, so to speak.)
When you've finished defining the new ID column, the designer will look like this illustration:
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To create the next column, click in the box in the Name column. Enter "Title" for the column and
then select nvarchar for the Data Type value. The "var" part of nvarchar tells the database that
the data for this column will be a string whose size might vary from record to record. (The "n"
prefix represents "national," which indicates that the field can hold character data for any
alphabet or writing system — that is, the field holds Unicode data.)
When you choose nvarchar, another box appears where you can enter the maximum length for
the field. Enter 50, on the assumption that no movie title that you'll work with in this tutorial will
be longer than 50 characters.
Skip Default Value and clear the Allow Nulls option. You don't want the database to allow any
movies to be entered into the database that don't have a title.
When you're done and move to the next row, the designer looks like this illustration:
Repeat these steps to create a column named "Genre", except for the length, set it to just 30.
Create another column named "Year." For the data type, choose nchar (not nvarchar) and set the
length to 4. For the year, you're going to use a 4-digit number like "1995" or "2010", so you don't
require a variable-sized column.
Here's what the finished design looks like:
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Press Ctrl+S or click the Save button in the Quick Access toolbar. Close the database designer by
closing the tab.
Adding Some Example Data
Later in this tutorial series you'll create a page where you can enter new movies in a form. For
now, however, you can add some example data that you can then display on a page.
In the Database workspace in WebMatrix, notice that there's a tree that shows you the .sdf file
you created earlier. Open the node for your new .sdf file, and then open the Tables node.
Right-click the Movies node and then choose Data. WebMatrix opens a grid where you can enter
data for the Movies table:
Click the Title column and enter "When Harry Met Sally". Move to the Genre column (you can use
the Tab key) and enter "Romantic Comedy". Move to the Year column and enter "1989":
Press Enter, and WebMatrix saves the new movie. Notice that the ID column has been filled in.
Enter another movie (for example, "Gone with the Wind", "Drama", "1939"). The ID column is
filled in again:
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Enter a third movie (for example, "Ghostbusters", "Comedy"). As an experiment, leave the Year
column blank and then press Enter. Because you unselected the Allow Nulls option, the database
shows an error:
Click OK to go back and fix the entry (the year for "Ghostbusters" is 1984), and then press Enter.
Fill in several movies until you have 8 or so. (Entering 8 makes it easier to work with paging later.
But if that's too many, enter just a few for now.) The actual data doesn't matter.
If you entered all the movies without any errors, the ID values are sequential. If you tried to save
an incomplete movie record, the ID numbers might not be sequential. If so, that's okay. The
numbers don't have any inherent meaning, and the only thing that's important is that they're
unique in the Movies table.
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Close the tab that contains the database designer.
Now you can turn to displaying this data on a web page.
Adding the Web Data Package
You access data in ASP.NET Web Pages sites using helpers that are available in the WebData
package. Because you used the Empty Site template in WebMatrix to create your Movies site, the
WebData package isn't automatically included. Therefore, you have to add the package to your
site.
In the left pane, click the Files workspace.
In the ribbon, click the Gallery button.
The NuGet Gallery is displayed.
In the search box, enter "Microsoft.AspNet.WebPages.WebData" to narrow down the list of
packages that are displayed.
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Select the Microsoft ASP.NET Web Pages 2 Web Data package and then click Install.
The Gallery page displays details about the package.
Click Install. After you accept the license, WebMatrix installs the Web Data package.
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Now you're ready to display data on a page.
Displaying Data in a Page by Using the WebGrid Helper
To display data in a page, you're going to use the WebGrid helper. This helper produces a display in
a grid or table (rows and columns). As you'll see, you'll be able refine the grid with formatting and
other features.
To run the grid, you'll have to write a few lines of code. These few lines will serve as a kind of
pattern for almost all of the data access that you do in this tutorial.
Note You actually have many options for displaying data on a page; the WebGrid helper is
just one. We chose it for this tutorial because it's the easiest way to display data and
because it's reasonably flexible. In the next tutorial set, you'll see how to use a more
"manual" way to work with data in the page, which gives you more direct control over how
to display the data.
In the left pane in WebMatrix, click the Files workspace. In the tree view, select the root of the
website.
The new database you created is in the App_Data folder. If the folder didn't already exist,
WebMatrix created it for your new database. (The folder might have existed if you'd previously
installed helpers.)
In the ribbon, click New. In the Choose a File Type box, choose CSHTML.
In the Name box, name the new page "Movies.cshtml":
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Click the OK button. WebMatrix opens a new file with some skeleton elements in it. First you'll
write some code to go get the data from the database. Then you'll add markup to the page to
actually display the data.
Writing the Data Query Code
At the top of the page, between the @{ and } characters, enter the following code. (Make sure
that you enter this code between the opening and closing braces.)
var db = Database.Open("WebPagesMovies");
var selectedData = db.Query("SELECT * FROM Movies");
var grid = new WebGrid(source: selectedData);
The first line opens the database that you created earlier, which is always the first step before
doing something with the database. You tell the Database.Open method name of the database to
open. Notice that you don't include .sdf in the name. The Open method assumes that it's looking
for an .sdf file (that is, WebPagesMovies.sdf) and that the .sdf file is in the App_Data folder.
(Earlier we noted that the App_Data folder is reserved; this scenario is one of the places where
ASP.NET makes assumptions about that name.)
When the database is opened, a reference to it is put into the variable named db. (Which could be
named anything.) The db variable is how you'll end up interacting with the database.
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The second line actually fetches the database data by using the Query method. Notice how this
code works: the db variable has a reference to the opened database, and you invoke the Query
method by using the db variable (db.Query).
Thequery itself is a SQL Select statement. (For a little background about SQL, see the explanation
later.) In the statement, Movies identifies the table to query. The * character specifies that the
query should return all the columns from the table. (You could also list columns individually,
separated by commas.)
The results of the query, if any, are returned and made available in the selectedData variable.
Again, the variable could be named anything.
Finally, the third line tells ASP.NET that you want to use an instance of the WebGrid helper. You
create (instantiate) the helper object by using the new keyword and pass it the query results via
the selectedData variable. The new WebGrid object, along with the results of the database query,
are made available in the grid variable. You'll need that result in a moment to actually display the
data in the page.
At this stage, the database has been opened, you've gotten the data you want, and you've
prepared the WebGrid helper with that data. Next is to create the markup in the page.
Structured Query Language (SQL)
SQL is a language that's used in most relational databases for managing data in a database. It
includes commands that let you retrieve data and update it, and that let you create, modify, and
manage data in database tables. SQL is different than a programming language (like C#). With
SQL, you tell the database what you want, and it's the database's job to figure out how to get the
data or perform the task. Here are examples of some SQL commands and what they do:
Select * From Movies
SELECT ID, Name, Price FROM Product WHERE Price > 10.00 ORDER BY Name
The first Select statement gets all the columns (specified by *) from the Movies table.
The second Select statement fetches the ID, Name, and Price columns from records in the
Product table whose Price column value is more than 10. The command returns the results in
alphabetical order based on the values of the Name column. If no records match the price criteria,
the command returns an empty set.
INSERT INTO Product (Name, Description, Price) VALUES ('Croissant', 'A flaky delight',
1.99)
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This command inserts a new record into the Product table, setting the Name column to
"Croissant", the Description column to "A flaky delight", and the price to 1.99.
Notice that when you're specifying a non-numeric value, the value is enclosed in single quotation
marks (not double quotation marks, as in C#). You use these quotation marks around text or date
values, but not around numbers.
DELETE FROM Product WHERE ExpirationDate < '01/01/2008'
This command deletes records in the Product table whose expiration date column is earlier than
January 1, 2008. (The command assumes that the Product table has such a column, of course.)
The date is entered here in MM/DD/YYYY format, but it should be entered in the format that's
used for your locale.
The Insert and Delete commands don’t return result sets. Instead, they return a number that
tells you how many records were affected by the command.
For some of these operations (like inserting and deleting records), the process that's requesting
the operation has to have appropriate permissions in the database. That's why for production
databases you often have to supply a user name and password when you connect to the
database.
There are dozens of SQL commands, but they all follow a pattern like the commands you see
here. You can use SQL commands to create database tables, count the number of records in a
table, calculate prices, and perform many more operations.
Adding Markup to Display the Data
Inside the element, set contents of the element to "Movies":
<head>
<meta charset="utf-8" />
<title>Movies
Inside the element of the page, add the following:
element. (If you want, you can verify the
rendering by looking at the source of the page in the browser.)
Modifying the Look of the Grid
Using the WebGrid helper like you just did is easy, but the resulting display is plain. The WebGrid
helper has all sorts of options that let you control how the data is displayed. There are far too
many to explore in this tutorial, but this section will give you an idea of some of those options. A
few additional options will be covered in later tutorials in this series.
Specifying Individual Columns to Display
To start, you can specify that you want to display only certain columns. By default, as you've seen,
the grid shows all four of the columns from the Movies table.
In the Movies.cshtml file, replace the @grid.GetHtml() markup that you just added with the
following:
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@grid.GetHtml(
columns: grid.Columns(
grid.Column("Title"),
grid.Column("Genre"),
grid.Column("Year")
)
)
To tell the helper which columns to display, you include a columns parameter for the GetHtml
method and pass in a collection of columns. In the collection, you specify each column to include.
You specify an individual column to display by including a grid.Column object, and pass in the
name of the data column you want. (These columns must be included in the SQL query results —
the WebGrid helper cannot display columns that were not returned by the query.)
Launch the Movies.cshtml page in the browser again, and this time you get a display like the
following one (notice that no ID column is displayed):
Changing the Look of the Grid
There are quite a few more options for displaying columns, some of which will be explored in later
tutorials in this set. For now, this section will introduce you to ways in which you can style the grid
as a whole.
Inside the section of the page, just before the closing tag, add the following
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This CSS markup defines classes named grid, head, and so on. You could also put these style
definitions in a separate .css file and link that to the page. (In fact,you'll do that later in this
tutorial set.) But to make things easy for this tutorial, they're inside the same page that displays
the data.
Now you can get the WebGrid helper to use these style classes. The helper has a number of
properties (for example, tableStyle) for just this purpose — you assign a CSS style class name to
them, and that class name is rendered as part of the markup that's rendered by the helper.
Change the grid.GetHtml markup so that it now looks like this code:
@grid.GetHtml(
tableStyle: "grid",
headerStyle: "head",
alternatingRowStyle: "alt",
columns: grid.Columns(
grid.Column("Title"),
grid.Column("Genre"),
grid.Column("Year")
)
)
What's new here is that you've added tableStyle, headerStyle, and alternatingRowStyle
parameters to the GetHtml method. These parameters have been set to the names of the CSS
styles that you added a moment ago.
Run the page, and this time you see a grid that looks much less plain than before:
To see what the GetHtml method generated, you can look at the source of the page in the
browser. We won't go into detail here, but the important point is that by specifying parameters
like tableStyle, you caused the grid to generate HTML tags like the following:
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The tag has had a class attribute added to it that references one of the CSS rules that you
added earlier. This code shows you the basic pattern — different parameters for the GetHtml
method let you reference CSS classes that the method then generates along with the markup.
What you do with the CSS classes is up to you.
Adding Paging
As the last task for this tutorial, you'll add paging to the grid. Right now it's no problem to display
all your movies at once. But if you added hundreds of movies, the page display would get long.
In the page code, change the line that creates the WebGrid object to the following code:
var grid = new WebGrid(source: selectedData, rowsPerPage: 3);
The only difference from before is that you've added a rowsPerPage parameter that's set to 3.
Run the page. The grid displays 3 rows at a time, plus navigation links that let you page through
the movies in your database:
Coming Up Next
In the next tutorial, you'll learn how to use Razor and C# code to get user input in a form. You'll
add a search box to the Movies page so that you can find movies by title or genre.
Additional Resources
• Complete Listing for Movies Page
•
Introduction to ASP.NET Web Programming Using the Razor Syntax
Introducing ASP.NET Web Pages 2
Tutorial 3: Displaying Data
55
Tutorial 4: HTML Form Basics
This tutorial shows you the basics of how to create an input form and how to handle the user's
input when you use ASP.NET Web Pages (Razor). And now that you've got a database, you'll use
your form skills to let users find specific movies in the database.
What you'll learn:
• How to create a form by using standard HTML elements.
• How to read the user's input in a form.
• How to create a SQL query that selectively gets data by using a search term that the user
supplies.
• How to have fields in the page "remember" what the user entered.
Features/technologies discussed:
• The Request object.
• The SQL Where clause.
What You'll Build
In the previous tutorial, you created a database, added data to it, and then used the WebGrid
helper to display the data. In this tutorial,you'll add a search box that lets you find movies of a
specific genre or whose title contains whatever word you enter. (For example, you'll be able to
find all movies whose genre is "Action" or whose title contains "Harry" or "Adventure.")
When you're done with this tutorial, you'll have a page like this one:
The listing part of the page is the same as in the last tutorial — a grid. The difference will be that
the grid will show only the movies that you searched for.
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About HTML Forms
(If you've got experience with creating HTML forms and with the difference between GET and
POST, you can skip this section.)
A form has user input elements — text boxes, buttons, radio buttons, check boxes, drop-down
lists, and so on. Users fill in these controls or make selections and then submit the form by clicking
a button.
The basic HTML syntax of a form is illustrated by this example:
When this markup runs in a page, it creates a simple form that looks like this illustration:
The
@TwitterGoodies.FollowButton("microsoft")
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This code calls the FollowButton method of the TwitterGoodies helper. As you can guess, the
method adds a Follow Me on Twitter button. You pass a Twitter name to this method to indicate
who to follow.
Run the page and you see the Follow Me button:
Click it, and you go to the Twitter page for the user you specified.
As before, you can look at the source of the page in the browser to see what the Twitter helper
generated for you. This time the code looks something like the following example:
Again, you could have written this code yourself, but the helper makes it much easier.
Server-Side (Razor) and Client-Side (JavaScript) Programming
How does Razor code in an ASP.NET Web Pages relate to JavaScript code that runs in the
browser? If you've got experience with JavaScript, you might realize as you work with these
tutorials that many of the tasks could also be done in JavaScript. That's true, especially with the
simple examples you've seen so far.
A .cshtml page can contain both Razor code and JavaScript code. The traditional division of labor
has been that server code handled tasks that it made sense to run on the server. This included
accessing resources like a shared database and performing various types of business logic. In
contrast, client code has typically been used to create a rich user experience. Pop-up calendars,
sliders, animations, and many other UI effects are created by client code, and can all be done
easily using JavaScript libraries (especially jQuery).
These days the distinction has blurred a little because client code libraries now let you
communicate with the server in ways that formerly could only be done in server code. In general,
though, it's still useful to think of server code (Razor and C#) as being for back-end work and client
code (JavaScript) as useful for UI. In subsequent tutorial sets you'll learn how to integrate
JavaScript into a .cshtml page for just this purpose, namely to create a lively user experience.
Coming Up Next
To keep this tutorial short, we had to focus on only a few basics. Naturally, there's a lot more to
Razor and C#. You'll learn more as you go through these tutorials. If you're interested in learning
Introducing ASP.NET Web Pages 2
Tutorial 2: Programming Basics
37
more about the programming aspects of Razor and C# right now, you can read a more thorough
introduction here:Introduction to ASP.NET Web Programming Using the Razor Syntax.
The next tutorial introduces you to working with a database. In that tutorial, you'll begin creating
the sample application that lets you list your favorite movies.
Additional Resources
• Complete Listing for Test Razor Page
• Complete Listing for TestRazorPart2 Page
• Complete Listing for TwitterTest Page
•
Introduction to ASP.NET Web Programming Using the Razor Syntax
Introducing ASP.NET Web Pages 2
Tutorial 2: Programming Basics
38
Tutorial 3: Displaying Data
This tutorial shows you how to create a database in WebMatrix and how to display database data
in a page when you use ASP.NET Web Pages (Razor).
What you'll learn:
• How to use WebMatrix tools to create a database and database tables.
• How to use WebMatrix tools to add data to a database.
• How to display data from the database on a page.
• How to run SQL commands in ASP.NET Web Pages.
• How to customize the WebGrid helper to change the data display and to add paging and
sorting.
Features/technologies discussed:
• WebMatrix database tools.
•
WebGrid helper.
What You'll Build
In the previous tutorial, you were introduced to ASP.NET Web Pages (.cshtml files), to the basics
of Razor syntax, and to helpers. In this tutorial, you'll begin creating the actual web application
that you'll use for the rest of the series. The app is a simple movie application that lets you view,
add, change, and delete information about movies.
When you're done with this tutorial, you'll be able to view a movie listing that looks like this page:
But to begin, you have to create a database.
Introducing ASP.NET Web Pages 2
Tutorial 3: Displaying Data
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A Very Brief Introduction to Databases
This tutorial will provide only the briefest introduction to databases. If you have database
experience, you can skip this short section.
A database contains one or more tables that contain information — for example, tables for
customers, orders, and vendors,or for students, teachers, classes, and grades. Structurally, a
database table is like a spreadsheet. Imagine a typical address book. For each entry in the address
book (that is, for each person) you have several pieces of information such as first name, last
name, address, email address, and phone number.
(Rows are sometimes referred to as records, and columns are sometimes referred to as fields.)
For most database tables, the table has to have a column that contains a unique value, like a
customer number, account number, and so on. This value is known as the table's primary key, and
you use it to identify each row in the table. In the example, the ID column is the primary key for
the address book shown in the previous example.
Much of the work you do in web applications consists of reading information out of the database
and displaying it on a page. You'll also often gather information from users and add it to a
database, or you'll modify records that are already in the database. (We'll cover all of these
operations in the course of this tutorial set.)
Database work can be enormously complex and can require specialized knowledge. For this
tutorial set, though, you have to understand only basic concepts, which will all be explained as
you go.
Creating a Database
WebMatrix includes tools that make it easy to create (or define) a database and to create tables in
the database. For this tutorial set, you'll create a database that has only one table in it — Movies.
Open WebMatrix if you haven't already done so, and open the WebPagesMovies site that you
created in the previous tutorial.
In the left pane, click the Database workspace.
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The ribbon changes to show database-related tasks. In the ribbon, click New Database.
WebMatrix creates a database (an .sdf file) that has the same name as your site —
WebPagesMovies.sdf. (You won't do this here, but you can rename the file to anything you like, as
long as it has an .sdf extension.)
Creating a Table
In the ribbon, click New Table. WebMatrix opens the table designer in a new tab. (If the New
Table option isn't available, make sure that the new database is selected in the tree view on the
left.)
In the text box at the top (where the watermark says "Enter table name"), enter "Movies".
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The pane underneath the table name is where you define individual columns. For the Movies
table in this tutorial, you'll create only a few columns: ID, Title, Genre, and Year.
In the Name box, enter "ID". Entering a value here activates all the controls for the new column.
Tab to the Data Type list and choose int. This value specifies that the ID column will contain
integer (number) data.
Note We won't call it out any more here (much), but you can use standard Windows
keyboard gestures to navigate in this grid. For example, you can tab between fields, you
can just start typing in order to select an item in a list, and so on.
Tab past the Default Value box (that is, leave it blank). Tab to the Is Primary Key check box and
select it. This option tells the database that the ID column will contain the data that identifies
individual rows. (That is, each row will have a unique value in the ID column that you can use to
find that row.)
Choose the Is Identity option. This option tells the database that it should automatically generate
the next sequential number for each new row. (The Is Identity option works only if you've also
selected the Is Primary Key option.)
Click in the next grid row, or press Tab twice to finish the current row. Either gesture saves the
current row and starts the next one. Notice that the Default Value column now says Null. (Null is
the default value for the default value, so to speak.)
When you've finished defining the new ID column, the designer will look like this illustration:
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To create the next column, click in the box in the Name column. Enter "Title" for the column and
then select nvarchar for the Data Type value. The "var" part of nvarchar tells the database that
the data for this column will be a string whose size might vary from record to record. (The "n"
prefix represents "national," which indicates that the field can hold character data for any
alphabet or writing system — that is, the field holds Unicode data.)
When you choose nvarchar, another box appears where you can enter the maximum length for
the field. Enter 50, on the assumption that no movie title that you'll work with in this tutorial will
be longer than 50 characters.
Skip Default Value and clear the Allow Nulls option. You don't want the database to allow any
movies to be entered into the database that don't have a title.
When you're done and move to the next row, the designer looks like this illustration:
Repeat these steps to create a column named "Genre", except for the length, set it to just 30.
Create another column named "Year." For the data type, choose nchar (not nvarchar) and set the
length to 4. For the year, you're going to use a 4-digit number like "1995" or "2010", so you don't
require a variable-sized column.
Here's what the finished design looks like:
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Press Ctrl+S or click the Save button in the Quick Access toolbar. Close the database designer by
closing the tab.
Adding Some Example Data
Later in this tutorial series you'll create a page where you can enter new movies in a form. For
now, however, you can add some example data that you can then display on a page.
In the Database workspace in WebMatrix, notice that there's a tree that shows you the .sdf file
you created earlier. Open the node for your new .sdf file, and then open the Tables node.
Right-click the Movies node and then choose Data. WebMatrix opens a grid where you can enter
data for the Movies table:
Click the Title column and enter "When Harry Met Sally". Move to the Genre column (you can use
the Tab key) and enter "Romantic Comedy". Move to the Year column and enter "1989":
Press Enter, and WebMatrix saves the new movie. Notice that the ID column has been filled in.
Enter another movie (for example, "Gone with the Wind", "Drama", "1939"). The ID column is
filled in again:
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Enter a third movie (for example, "Ghostbusters", "Comedy"). As an experiment, leave the Year
column blank and then press Enter. Because you unselected the Allow Nulls option, the database
shows an error:
Click OK to go back and fix the entry (the year for "Ghostbusters" is 1984), and then press Enter.
Fill in several movies until you have 8 or so. (Entering 8 makes it easier to work with paging later.
But if that's too many, enter just a few for now.) The actual data doesn't matter.
If you entered all the movies without any errors, the ID values are sequential. If you tried to save
an incomplete movie record, the ID numbers might not be sequential. If so, that's okay. The
numbers don't have any inherent meaning, and the only thing that's important is that they're
unique in the Movies table.
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Close the tab that contains the database designer.
Now you can turn to displaying this data on a web page.
Adding the Web Data Package
You access data in ASP.NET Web Pages sites using helpers that are available in the WebData
package. Because you used the Empty Site template in WebMatrix to create your Movies site, the
WebData package isn't automatically included. Therefore, you have to add the package to your
site.
In the left pane, click the Files workspace.
In the ribbon, click the Gallery button.
The NuGet Gallery is displayed.
In the search box, enter "Microsoft.AspNet.WebPages.WebData" to narrow down the list of
packages that are displayed.
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Select the Microsoft ASP.NET Web Pages 2 Web Data package and then click Install.
The Gallery page displays details about the package.
Click Install. After you accept the license, WebMatrix installs the Web Data package.
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Now you're ready to display data on a page.
Displaying Data in a Page by Using the WebGrid Helper
To display data in a page, you're going to use the WebGrid helper. This helper produces a display in
a grid or table (rows and columns). As you'll see, you'll be able refine the grid with formatting and
other features.
To run the grid, you'll have to write a few lines of code. These few lines will serve as a kind of
pattern for almost all of the data access that you do in this tutorial.
Note You actually have many options for displaying data on a page; the WebGrid helper is
just one. We chose it for this tutorial because it's the easiest way to display data and
because it's reasonably flexible. In the next tutorial set, you'll see how to use a more
"manual" way to work with data in the page, which gives you more direct control over how
to display the data.
In the left pane in WebMatrix, click the Files workspace. In the tree view, select the root of the
website.
The new database you created is in the App_Data folder. If the folder didn't already exist,
WebMatrix created it for your new database. (The folder might have existed if you'd previously
installed helpers.)
In the ribbon, click New. In the Choose a File Type box, choose CSHTML.
In the Name box, name the new page "Movies.cshtml":
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Click the OK button. WebMatrix opens a new file with some skeleton elements in it. First you'll
write some code to go get the data from the database. Then you'll add markup to the page to
actually display the data.
Writing the Data Query Code
At the top of the page, between the @{ and } characters, enter the following code. (Make sure
that you enter this code between the opening and closing braces.)
var db = Database.Open("WebPagesMovies");
var selectedData = db.Query("SELECT * FROM Movies");
var grid = new WebGrid(source: selectedData);
The first line opens the database that you created earlier, which is always the first step before
doing something with the database. You tell the Database.Open method name of the database to
open. Notice that you don't include .sdf in the name. The Open method assumes that it's looking
for an .sdf file (that is, WebPagesMovies.sdf) and that the .sdf file is in the App_Data folder.
(Earlier we noted that the App_Data folder is reserved; this scenario is one of the places where
ASP.NET makes assumptions about that name.)
When the database is opened, a reference to it is put into the variable named db. (Which could be
named anything.) The db variable is how you'll end up interacting with the database.
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The second line actually fetches the database data by using the Query method. Notice how this
code works: the db variable has a reference to the opened database, and you invoke the Query
method by using the db variable (db.Query).
Thequery itself is a SQL Select statement. (For a little background about SQL, see the explanation
later.) In the statement, Movies identifies the table to query. The * character specifies that the
query should return all the columns from the table. (You could also list columns individually,
separated by commas.)
The results of the query, if any, are returned and made available in the selectedData variable.
Again, the variable could be named anything.
Finally, the third line tells ASP.NET that you want to use an instance of the WebGrid helper. You
create (instantiate) the helper object by using the new keyword and pass it the query results via
the selectedData variable. The new WebGrid object, along with the results of the database query,
are made available in the grid variable. You'll need that result in a moment to actually display the
data in the page.
At this stage, the database has been opened, you've gotten the data you want, and you've
prepared the WebGrid helper with that data. Next is to create the markup in the page.
Structured Query Language (SQL)
SQL is a language that's used in most relational databases for managing data in a database. It
includes commands that let you retrieve data and update it, and that let you create, modify, and
manage data in database tables. SQL is different than a programming language (like C#). With
SQL, you tell the database what you want, and it's the database's job to figure out how to get the
data or perform the task. Here are examples of some SQL commands and what they do:
Select * From Movies
SELECT ID, Name, Price FROM Product WHERE Price > 10.00 ORDER BY Name
The first Select statement gets all the columns (specified by *) from the Movies table.
The second Select statement fetches the ID, Name, and Price columns from records in the
Product table whose Price column value is more than 10. The command returns the results in
alphabetical order based on the values of the Name column. If no records match the price criteria,
the command returns an empty set.
INSERT INTO Product (Name, Description, Price) VALUES ('Croissant', 'A flaky delight',
1.99)
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This command inserts a new record into the Product table, setting the Name column to
"Croissant", the Description column to "A flaky delight", and the price to 1.99.
Notice that when you're specifying a non-numeric value, the value is enclosed in single quotation
marks (not double quotation marks, as in C#). You use these quotation marks around text or date
values, but not around numbers.
DELETE FROM Product WHERE ExpirationDate < '01/01/2008'
This command deletes records in the Product table whose expiration date column is earlier than
January 1, 2008. (The command assumes that the Product table has such a column, of course.)
The date is entered here in MM/DD/YYYY format, but it should be entered in the format that's
used for your locale.
The Insert and Delete commands don’t return result sets. Instead, they return a number that
tells you how many records were affected by the command.
For some of these operations (like inserting and deleting records), the process that's requesting
the operation has to have appropriate permissions in the database. That's why for production
databases you often have to supply a user name and password when you connect to the
database.
There are dozens of SQL commands, but they all follow a pattern like the commands you see
here. You can use SQL commands to create database tables, count the number of records in a
table, calculate prices, and perform many more operations.
Adding Markup to Display the Data
Inside the element, set contents of the Movies
@grid.GetHtml()
That's it. The grid variable is the value you created when you created the WebGrid object in code
earlier.
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In the WebMatrix tree view, right-click the page and select Launch in browser.You'll see
something like this page:
(Remember that the URL that you see in the browser might use a different port number than
what you see in these screenshots — instead of locahost:56011, you'll see localhost followed by a
different number.)
Click a column heading link to sort by that column. Being able to sort by clicking a heading is a
feature that's built into the WebGrid helper.
The GetHtml method, as its name suggests, generates markup that displays the data. By default,
the GetHtml method generates an HTML