Figure 5-4. WSDL in the br owser Creating the Address Service Now it’s time to go beyond Hello World and provide a web service that exposes the address table from the AdventureWorks database. The web service will take a single parameter in the call: the postal code that will be used to filter the desired records. Because the service requires access to data, you will need to create a data connec- tion. To do this, you will use a strongly typed DataSet object in your solution. Creating this object is very straightforward. You’ll look at how to use the DataSet wizard to do this in the next section. CHAPTER 5 ■ ASP.NET WEB SERVICES112 9594CH05.qxd 1/22/08 10:31 AM Page 112 Adding Data to a Web Service To add a (strongly) typed DataSet to your web service, you use the Solution Explorer. Right-click your project and select Add New Item. The Add New Item dialog box displays (see Figure 5-5). Figure 5-5. Adding a typed DataSet to your project Select the DataSet and give it a friendly name. To use the code later in this section, for the purposes of this example, you should call it AddressData. The IDE will warn you that the code should be placed in the App_Code folder. Click Yes, and the TableAdapter Configu- ration wizard will launch. The first page of the wizard configures the desired database connection (see Figure 5-6). CHAPTER 5 ■ ASP.NET WEB SERVICES 113 9594CH05.qxd 1/22/08 10:31 AM Page 113 Figure 5-6. Configuring your database connection You can choose a configuration that is preconnected from either a known database or an existing Web.config setting (as shown in Figure 5-5). If you don’t have an existing connection, you can create one by clicking the New Connection button. If you want to look at the steps involved in doing this, refer to Chapters 3 and 4. Once you have selected your connection, click Next. This will take you to the com- mand type configuration page (see Figure 5-7). You can choose from three options on this page. The first is to use SQL statements embedded in your code (dynamic SQL), which can be used to select, insert, update, or delete data from the database. The second option enables you to create a stored proce- dure, which is precompiled code that resides on the database and therefore provides performance, security, and code maintenance benefits. Finally, if you have existing stored procedures in your database, you can use them by selecting the third option. For this example, pick the first option—because we will be using a parameterized SQL query and there is no existing stored procedure—and then click Next. The next page enables you to type or build the SQL that you’ll use to access the data- base. You can see this in Figure 5-8. CHAPTER 5 ■ ASP.NET WEB SERVICES114 9594CH05.qxd 1/22/08 10:31 AM Page 114 Figure 5-7. Choosing the command type Figure 5-8. Building your dynamic SQL statement CHAPTER 5 ■ ASP.NET WEB SERVICES 115 9594CH05.qxd 1/22/08 10:31 AM Page 115 You can manually type your SQL on this page (or cut and paste an existing known query), or you can use the Query Builder. Click the Query Builder button, and this builder will launch (see Figure 5-9). Figure 5-9. The Query Builder The Q uery Builder dialog box enables you to visually create your query. First, select the tables that y ou want to add to your query and the links that join them. In this case, a single table , Person.Address, is used. T o pick the fields that you want in your query, simply check the boxes beside the field names in the top pane . Then, in the center pane, you can specify a parameter by using the F ilter column. So, if you want to filter the returned data based on a parameterized postal code , you can place a filter called @ZIP on the PostalCode field. This embeds a CHAPTER 5 ■ ASP.NET WEB SERVICES116 9594CH05.qxd 1/22/08 10:31 AM Page 116 parameter called ZIP in the SQL statement. Later, when you write your code for the query, you’ll see how to use this parameter. Your SQL can be viewed and tested at the bottom of the screen. You’re now ready to hook this query up to your code and use it to expose the data from the database through the web service. Click OK on the Query Builder and click Finish to exit the wizard. You now have a typed DataSet in your project, tied to the Person.Address table, that can be seen in the Designer (see Figure 5-10). Figure 5-10. Viewing the DataSet in the Designer The Designer shows you the fields that are available once you run the query, as well as the methods (Fill and GetData) that are available to the programmer to write to and r ead from the database, respectively. Using the DataSet in a Web Method To retrieve the data in a strongly typed DataSet, you use the corresponding data adapter. So, by creating a strongly typed DataSet, such as AddressData, you’ll have a reference to the AddressDataTableAdapters collection. From this collection, you create an instance of an AddressTableAdapter, like this: AddressDataTableAdapters.AddressTableAdapter da = new AddressDataTableAdapters.AddressTableAdapter(); This table adapter implements the Fill and GetData methods that enable you to write and read data from the table, respectively. Because we specified a parameter ( @ZIP), the postal code value is passed as a parameter to the GetData method named strZIP. CHAPTER 5 ■ ASP.NET WEB SERVICES 117 9594CH05.qxd 1/22/08 10:31 AM Page 117 This returns an AddressDataTable object, so you can instantiate a new object like this: A ddressData.AddressDataTable dt = da.GetData(strZIP); You now have a data table containing the returned results from your query. However, you may not want to return this from your web method, because you may have clients written on J2EE, PHP, or other web technologies that will not be able to parse the AddressDataTable object (it is bound to ADO.NET and therefore .NET). A better approach is to use well-formed XML to return your data. In this case, you are returning addresses to the client, so you can set up a class to store a specific address, and another to contain a list of addresses. Here’s the code: public class Address { public string AddressLine1 = String.Empty; public string City = String.Empty; public string PostalCode = String.Empty; public int AddressID = -1; } public class Addresses : List<Address> { } Now your web method can build this list of addresses with the data that was returned from the database query. You can see the code that implements this here: [WebMethod] public Addresses GetAddress(string strZIP) { AddressDataSetTableAdapters.AddressTableAdapter da = new AddressDataSetTableAdapters.AddressTableAdapter(); AddressDataSet.AddressDataTable dt = da.GetData(strZIP); Addresses addrs = new Addresses(); foreach (AddressDataSet.AddressRow row in dt.Rows) { // Create a new Address object Address addr = new Address(); // Assign the new address information addr.AddressID = row.AddressID; addr.AddressLine1 = row.AddressLine1; CHAPTER 5 ■ ASP.NET WEB SERVICES118 9594CH05.qxd 1/22/08 10:31 AM Page 118 addr.City = row.City; addr.PostalCode = row.PostalCode; // Add to the list addrs.Add(addr); } // foreach return addrs; } This cycles through each row in the data table and creates an instance of the Address class with the data from that row. It then adds this instance to the list of addresses. Once the loop is complete (i.e., when you’ve iterated through each row), the list is returned to the caller. Figure 5-11 shows the results of running this web method in its test page. Figure 5-11. Running the GetAddresses web method in the test page CHAPTER 5 ■ ASP.NET WEB SERVICES 119 9594CH05.qxd 1/22/08 10:31 AM Page 119 You can type a postal code into the field on this form and click Invoke. You’ll get the results of the query, formatted as XML, returned to you (see Figure 5-12). Web service clients can now consume this XML and render it as they please. Figure 5-12. The XML returned from the web service Creating a Web Service Client Visual Studio offers you a convenient way to create clients for web services via a facility called web references.When adding a web reference, you point the IDE’s Add Web Refer- ence dialog box at the WSDL document for the web service, and Visual Studio will create a proxy class that talks to the service on your behalf (you saw this process in Chapter 2). CHAPTER 5 ■ ASP.NET WEB SERVICES120 9594CH05.qxd 1/22/08 10:31 AM Page 120 In order to add a web reference, and therefore use the underlying web service, the first thing you’ll need is the WSDL for your web service. You can get this by appending ?WSDL to the URL of your service if it is an ASP.NET web service (the mechanism for other services varies and is beyond the scope of this chapter to describe). For example, if your service’s endpoint is located at http://url/Service.asmx, you can get the WSDL by using the URL http://url/Service.asmx?WSDL. Knowing this, you can create a client web site, a Windows application, or another web service to easily consume this service. From your project, right-click the project name in the Solution Explorer and select Add Web Reference. You’ll see the Add Web Ref- erence dialog box, as in Figure 5-13. Use the URL field to enter the URL of the WSDL file, and then click Go. Figure 5-13. A dding a web reference Once the IDE parses the WSDL, the list of methods will be displayed, and the web reference name will be given a default value. It’s a good idea to change this name to something more meaningful before you click Add Reference. CHAPTER 5 ■ ASP.NET WEB SERVICES 121 9594CH05.qxd 1/22/08 10:31 AM Page 121 [...]... Connect button Click this to specify the server that you want to connect to One helpful feature is that if you specify an IIS server and a URL containing a subdirectory, IIS will automatically create the virtual web directory for you So for example, if you want to deploy the web service to a virtual web directory called ServiceTier, you simply add it to the URL of the server you want to open and then... 9594CH05.qxd 1/22/08 10:31 AM Page 127 CHAPTER 5 s ASP.NET WEB SERVICES Summary This chapter introduced you to web services and their architecture You looked at the theory of web services and how the group of technologies—HTTP, SOAP, XML, and WSDL—are used in the Web Services ecosystem You then looked into how to create a web service using Visual Studio and Visual Web Developer Express You looked into... into how to tie a web service to databases using DataSets, and finally you built a web service client by using the IDE to access the WSDL document for your web service to generate a proxy class This client then consumed the data and used it in a data-binding scenario with a GridView control 127 9594CH05.qxd 1/22/08 10:31 AM Page 128 9594CH06.qxd 1/ 14/ 08 3 :40 PM CHAPTER Page 129 6 Deploying Your Web Site... process, an error in one application will not affect others 139 9594CH06.qxd 140 1/ 14/ 08 3 :40 PM Page 140 CHAPTER 6 s DEPLOYING YOUR WEB SITE Configuring Your Data Connections Remember, your web service is connected to your database, so the first step is to change the web service connection from pointing to your local database to pointing to the server-based one You do this by changing the connection string... the database 141 9594CH06.qxd 142 1/ 14/ 08 3 :40 PM Page 142 CHAPTER 6 s DEPLOYING YOUR WEB SITE This, in turn, means you’ll need to place a valid database username and password in your connection string You can configure existing Windows users or add new database users to SQL Server directly from within the management console (see Figure 6- 14) Figure 6- 14 Database user administration From Object Explorer,... find the database in Object Explorer and expand it until you see the Users node (see Figure 6-16) 143 9594CH06.qxd 144 1/ 14/ 08 3 :40 PM Page 144 CHAPTER 6 s DEPLOYING YOUR WEB SITE Figure 6-16 Configuring database users At this point, Object Explorer shows the list of approved database users and their associated login accounts that are configured to have access to the database Windows usernames will... of the virtual directory and not of the machine itself Thus, you can specify different versions of aspnet_isapi.dll to handle each site Therefore, you can configure a site in one virtual directory to use ASP.NET 2.0 and another site in a different virtual directory to use ASP NET 3.0 Thus, a single web server isn’t bound to a specific version of ASP.NET Manually Deploying Your ASP.NET Applications... virtual directory to run your application A virtual directory maps a URL (Universal Resource Locator, or in other words, the Internet address for the page you’re about to display) to a physical directory handled by IIS For example, if you have a directory C:\MyApp on your server, you can configure IIS to treat this as a web application by configuring it as a virtual directory The virtual directory will... know the web service is just reading data, so the db_datareader role is selected 9594CH06.qxd 1/ 14/ 08 3 :40 PM Page 145 CHAPTER 6 s DEPLOYING YOUR WEB SITE Figure 6-17 Adding a user to your database By this point, you should be able to sign into the database that resides on your database server from the web service that resides on your web development system by changing the connection string to use the... en-us/library/dtkwfdky.aspx 145 9594CH06.qxd 146 1/ 14/ 08 3 :40 PM Page 146 CHAPTER 6 s DEPLOYING YOUR WEB SITE Deploying Your Service Tier The best way to deploy your application is to use the IDE to deploy it directly to the server Visual Studio will perform most if not all of the IIS administration for you if you do Before deploying, though, you should once again edit your Web. config file You’ll see that in the default Web. config, . 5-17. CHAPTER 5 ■ ASP. NET WEB SERVICES1 24 9594CH05.qxd 1/22/08 10:31 AM Page 1 24 Figure 5-17. Binding the input parameters Next, finish the wizard, and the ASP. NET code for the ObjectDataSource and form bindings. XML, and WSDL—are used in the Web Services ecosystem. You then looked into how to create a web service using Visual Studio and Visual Web Developer Express. You looked into how to tie a web service. You’ll look at how to use the DataSet wizard to do this in the next section. CHAPTER 5 ■ ASP. NET WEB SERVICES112 9594CH05.qxd 1/22/08 10:31 AM Page 112 Adding Data to a Web Service To add a (strongly)