Tài liệu Module 7: Building and Consuming a Web Service That Uses ADO.NET ppt

Contents Overview 1 Lesson: Building and Consuming a Web Service That Returns Data 2 Review 15 Lab 7.1: Troubleshooting an ADO.NET Application 16 Course Evaluation 25 Module 7: Building and Consuming a Web Service That Uses ADO.NET Information in this document, including URL and other Internet Web site references, is subject to change without notice. Unless otherwise noted, the example companies, organizations, products, domain names, e-mail addresses, logos, people, places, and events depicted herein are fictitious, and no association with any real company, organization, product, domain name, e-mail address, logo, person, places or events is intended or should be inferred. Complying with all applicable copyright laws is the responsibility of the user. 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Microsoft, MS-DOS, Windows, Windows NT, Win32, Active Directory, ActiveX, BizTalk, IntelliSense, JScript, MSDN, SQL Server, Visual Basic, Visual C#, Visual C++, Visual J#, Visual Studio, and Windows Media are either registered trademarks or trademarks of Microsoft Corporation in the U.S.A. and/or other countries. The names of actual companies and products mentioned herein may be the trademarks of their respective owners. Module 7: Building and Consuming a Web Service That Uses ADO.NET iii Instructor Notes This module teaches students how to build a simple Web service that queries a database. It also explains how to consume the Web service in a client application. After completing this module, students will be able to: ! Build a Web service. ! Consume a Web service in a client application. ! Troubleshoot errors in a Microsoft ® ADO.NET application. The lab for this module is optional. To teach this module, you need the following materials: ! Microsoft PowerPoint ® file 2389B_07.ppt ! Module 7, “Building and Consuming a Web Service That Uses ADO.NET” ! Lab 7.1, “Debugging a Windows Application and an XML Web Service That Uses ADO.NET” To prepare for this module: ! Read all of the materials for this module. ! Complete the practices and labs. ! Read the latest .NET Development news at http://msdn.microsoft.com/library/default.asp?url=/nhp/Default.asp?contenti d=28000519 This module contains code examples that are linked to text hyperlinks at the bottom of PowerPoint slides. These examples enable you to teach from code examples that are too long to display on a slide. All the code examples for this module are contained in one .htm file. Students can copy the code directly from the browser or from the source, and paste it into a development environment. To display a code sample, click a text hyperlink on a slide. Each link opens an instance of Microsoft Internet Explorer and displays the code associated with the link. At the end of each example is a link that displays a table of contents of all examples in this module. After you have finished teaching the code for an example, close the instance of the browser to conserve resources. If time constraints occur, one or more practices in this module can be presented as instructor-led demonstrations. Presentation: 30 Minutes Lab (optional): 120 Minutes Note Required materials Preparation tasks Hyperlinked code examples Practices iv Module 7: Building and Consuming a Web Service That Uses ADO.NET Use Microsoft SQL Server ™ Query Analyzer to run the SQL script named setuplab7.sql in the Lab07 folder on the Instructor computer. This will create a copy of the Employees table named EmployeesLatest. It will also create a new login called MaryJane with a password of secret. Do NOT run this script on the student computers. Remind the students that they must use SQL Server Query Analyzer to run the SQL script named lab6setup.sql in the Lab06_1 folder on the student computers. This will ensure that all of the correct stored procedures for this lab have been created. The application is not designed to be a complete production quality app. The design of the app assumes that if the user adds a new customer they will have to add an order for that customer too. If they do not, there is no way to cause that customer to appear in the initial Customers grid on refresh because the select statement for that grid is based on EmployeeID. Without Order information associated with the added Customer there is no EmployeeID associated to select on. Classroom lab setup Note Module 7: Building and Consuming a Web Service That Uses ADO.NET v How to Teach This Module This section contains information that will help you to teach this module. Lesson: Building and Consuming a Web Service That Returns Data This section describes the instructional methods for teaching each topic in this lesson. Technical Notes: This lesson describes a Web service as an application component. You should stress that Web services accept XML as input and generate XML as output. Keep this discussion at a high level. Discussion Questions: Personalize the following questions to the background of the students in your class. ! What are some other examples of Web services? Passport, Microsoft .NET My Services ! How could Web services be used in your organization? Give examples. Technical Notes: You might want to build a simple ASP.NET Web service by creating a new Web service in Microsoft Visual Studio ® .NET and clearing the comment from the “Hello World” public function. Then, view the Service1.asmx page in Internet Explorer and test the function. Do not spend more than 5 minutes on this demonstration. Discussion Questions: Personalize the following questions to the background of the students in your class. ! What are some other ways that you could fill the local DataSet with data other than by using a DataAdapter? ! What is the purpose of creating an empty, local instance of a DataSet? ! Why use a strongly typed DataSet? Transition to Practice Exercise: Now that you have seen examples of creating a Web service, you can practice creating a Web service programmatically. Instruct students to turn to the practice exercise at the end of this topic in the student workbook. Practice Solution: The solution for the Web Service is located in \Program Files\Msdntrain\2389\Practices\Mod07\Lesson1\ClientRosterService. Technical Notes: Stress that when you create a Web reference, you are importing method and class definitions from the Web service into your local project. If the Web service returns data as a DataSet rather than an XML stream, you should use the XML Schema Definition (XSD) file defined in the Web service to build a container for the returned data in the client application. To call a Web method, you must create a variable that points to the Web service. You can then use the Web methods as if they were local to your project. What Is a Web Service? How to Build a Web Service That Returns Database Information How to Consume a Web Service vi Module 7: Building and Consuming a Web Service That Uses ADO.NET Discussion Questions: Personalize the following questions to the background of the students in your class. ! What are some ways to find out the reference to Web services? ! How do you use Universal Description, Discover, and Integration (UDDI)? Transition to Practice Exercise: Now that you have seen examples of consuming a Web service, you can practice consuming a Web service in a client application. Instruct students to turn to the practice exercise at the end of this topic in the student workbook. Practice Solution: The solution for the client application is located in \Program Files\Msdntrain\2389\Practices\Mod07\Lesson2\ClientList. Module 7: Building and Consuming a Web Service That Uses ADO.NET vii Review: Building and Consuming a Web Service That Uses ADO.NET This section provides the answers to review questions at the end of this module. 1. You are building a Web Service to return database information to a client application. How should you pass back query results to the client application? You should define a typed DataSet in the Web service. Use a database connection and execute a query to populate an instance of the dataset. Return the DataSet to the client. Alternatively, you could build an XML document that contains the query results in hierarchical format. Then, pass the results to the client as a stream. In this case, the client application could load a DataSet from this stream, inferring or reading schema information as needed. 2. You are building a client application that calls a Web service. What must you do before calling a Web method to return a DataSet? You must add a Web reference to the Visual Studio .Net project. This allows you to create a local instance of the typed DataSet defined in the Web service to capture results. This also allows you to call the Web service methods as if they were local to your application. Module 7: Building and Consuming a Web Service That Uses ADO.NET 1 Overview ! Building and Consuming a Web Service That Returns Data ! Lab 7.1: Troubleshooting an ADO.NET Application ***************************** ILLEGAL FOR NON - TRAINER USE ****************************** Web services allow applications to communicate regardless of operating system or programming language. Web services can be implemented on any platform and are defined through public standards organizations. Sharing data through Web services allows the Web services to be independent of each other while simultaneously enabling them to loosely link themselves into a collaborating group that performs a particular task. In this module, you will learn how to create a Web service that returns data. After completing this module, you will be able to: ! Build a Web service. ! Consume a Web service in a client application. ! Troubleshoot errors in a Microsoft® ADO.NET application. Introduction Objectives 2 Module 7: Building and Consuming a Web Service That Uses ADO.NET Lesson: Building and Consuming a Web Service That Returns Data ! What Is a Web Service? ! How to Build a Web Service That Returns Database Information ! How to Consume a Web Service ***************************** ILLEGAL FOR NON - TRAINER USE ****************************** Web services are making possible a new era of distributed application development. By using ADO.NET, you can build Web services that return data, and these Web services can be consumed by multiple applications locally or across the Internet. After completing this lesson, you will be able to: ! Explain what a Web service is. ! Build a Web service that returns data. ! Consume a Web service. Introduction Lesson objectives [...]... the Web service Finally, you call a Web method to return data to the client and populate the DataSet Module 7: Building and Consuming a Web Service That Uses ADO.NET 11 You can use Universal Description, Discovery, and Integration (UDDI) to find out what methods are available from the Web service When you find the Web service that you want to access, you need to add a Web reference to that Web service. .. XML-based response message for use in calculating the total charge to the customer 4 Module 7: Building and Consuming a Web Service That Uses ADO.NET How to Build a Web Service That Returns Database Information ! Web services that return database information typically: " " " " " Establish a connection to a data source Define the structure of a Typed DataSet (by using an xsd file) Create an empty instance... schema of the DataSet returned by the Web service 5 In the Class View, expand ClientList and then expand localhost Notice that a class named CustDS has been created In the next procedure, you will create a strongly typed DataSet based on this class 14 Module 7: Building and Consuming a Web Service That Uses ADO.NET ! Use the methods and classes from a Web service 1 From the Data tab of the toolbox, add... described above in the procedure Test your application Module 7: Building and Consuming a Web Service That Uses ADO.NET 15 Review ! Building and Consuming a Web Service That Returns Data ! Lab 7.1: Troubleshooting an ADO.NET Application *****************************ILLEGAL FOR NON-TRAINER USE****************************** 1 You are building a Web Service to return database information to a client application... you create parameterized queries by using the SqlDataAdapter object, use named arguments to mark parameters When you create parameterized queries by using the OleDbDataAdapter object, use the “?” character to mark parameters 'Example of a Web Service that returns a DataSet Imports System .Web. Services Public Class Service1 Inherits System .Web. Services.WebService 'This method accepts a city name as a query... DataSet ! Return the DataSet to the client application for further processing Module 7: Building and Consuming a Web Service That Uses ADO.NET Example The following example defines a Web method that takes a customer’s city as input, queries the Customers table in the Northwind database, and returns a DataSet with information about all of the customers in that city 'Connect to the Northwind DataBase... that is accessible by using standard Web protocols such as HTTP and XML A Web service can be used locally by a single application, or published on the Internet for use by many different applications Web services allow applications to share data and functionality, and use XML-based messaging to communicate between systems that use different component models, operating systems, and programming languages... operating system and in any language can access these services The decentralized nature of Web services enables both the client and the Web service to function as autonomous units Therefore, there are countless ways to consume a Web service For example, you can include a call to a Web service in a Web application, a middleware component, or even another Web service No matter what type of Web service client.. .Module 7: Building and Consuming a Web Service That Uses ADO.NET 3 What Is a Web Service? ! Programmable logic accessible through standard Web protocols XML Web Service TP HT Web Service XML Web Service L XM XML Web Web Service Service NET My Services Client *****************************ILLEGAL FOR NON-TRAINER USE****************************** Definition A Web service is a unit of programmable... Web service that returns data To build a Web service that returns data, you first create a new Web service by using Visual Studio NET Typically, this Web Service will: ! Establish a connection to a data source ! Define the structure of a typed DataSet (by using an xsd file) ! Create an empty instance of the typed DataSet ! Run a query or perform calculations, and fill the DataSet A DataAdapter is commonly . Building and Consuming a Web Service That Uses ADO. NET How to Build a Web Service That Returns Database Information ! Web services that return database information. Consuming a Web Service That Uses ADO. NET ! Lab 7.1, “Debugging a Windows Application and an XML Web Service That Uses ADO. NET To prepare for this module: