Professional Microsoft Smartphone Programming phần 4 docx

Integrated Security = SSPI; Inital Catalog=myCourses”); dbConn.Open(); SqlCommand sqlCmd = dbConn.CreateCommand(); sqlCmd.CommandText = “SELECT studentID, lastName FROM students”; sqlDataReader stuReader = sqlCmd.ExecuteReader(); while (stuReader.Read()) { Console.WriteLine(“{0}\t{1}”, stuReader.GetInt32(0), stuReader.GetString(1)); } stuReader.Close(); dbConn.Close(); In the preceding code, a SQL connection is first created by specifying the connection string and invoking the Open() method of the SqlConnection class. Then a SqlCommand object is instantiated to retrieve records in the studentID field and the lastName field from the table students. The results of the query are executed by the ExecuteReader() method of the SqlCommand class and are passed to a sqlDataReader object. By iterating the sqlDataReader object with the Read() method, data can be retrieved row by row. To retrieve the data in disconnected mode, a typical approach is to use a DataAdapater object to retrieve data from a data source and then populate the data to a DataSet object, which can hold multi- ple data tables in memory. The following code snippet demonstrates how to perform the same function in disconnected mode: using System; using System.Data; using System.Data.SqlClient; SqlConnection dbConn = new SqlConnection(“Data Source=localhost; Integrated Security = SSPI; Inital Catalog=myCourses”); string qStr = “SELECT studentID, lastName FROM students”; SqlDataAdapter stuAdapter = new SqlDataAdapter(qStr, dbConn); DataSet stuSet = new DataSet(); stuAdapter.Fill(stuSet, “students”); for (int i=0; i<=stuSet.Tables[“students”].Rows.Count-1; i++) { int ID = System.Convert.ToInt32( stuSet.Tables[“students”].Rows[i][“studentID”]); string name = stuSet.Tables[“students”].Rows[i][“lastName”].ToString(); System.Console.WriteLine(“{0}\t{1}”, ID, name); } In the preceding example, a SqlConnection object is first created. However, you do not need to maintain an open connection to the database by calling the open() method. Rather, a sqlDataApapter object is 133 Data Access with SQL Server Mobile 11_762935 ch06.qxp 11/20/06 7:56 AM Page 133 created with the same SQL query command string and the same database connection string. When the SqlAdapater.Fill() method is executed, an implicit connection to the database is established and the data in the table is populated to the DataSet object. Once the Fill() operation is finished, it closes the connection to the database. You can then access each column of the data from the in-memory data set by stating the name of the table, the index of the row, and the name of the column. This section only briefly introduces ADO.NET programming. For mobile devices, accessing a conven- tional database using either connected mode or disconnected mode may not be applicable because mobile devices do not have sufficient system memory and are not connected to the database servers all the time. In the following sections, you will learn how to access and manipulate data in a database that is designed for Windows Mobile devices. Microsoft SQL Server 2005 Mobile Edition The Microsoft SQL Server 2005 Mobile Edition (or, simply, SQL Server Mobile) is a lightweight database designed specifically for smart devices such as Smartphones, Pocket PCs, and Tablet PCs. Like its prede- cessor SQL Server CE, SQL Server Mobile is a trimmed-down version of Microsoft’s desktop database. It allows faster and easier data access while disconnected, and synchronizes the data between mobile devices and desktop SQL servers while connected. In addition to enhanced reliability and performance, SQL Server Mobile adds a number of notable features, as summarized in Table 6-1. Table 6-1 New Features of SQL Server Mobile Feature SQL Server CE SQL Server Mobile Multi-user support No (single user only) Yes Multi-subscription No. You need to create a separate Yes support subscriptiondatabase for each subscription. Column-level tracking No. The minimum synchronization Yes. With both column- and unit is a single row. row-level tracking, the minimum synchronization unit is a cell. Auto reuse empty pages No Yes. The auto-shrink feature will reuse the empty pages, thereby saving storage space. Integration with Visual No Yes Studio 2005 and SQL Server 2005 134 Chapter 6 11_762935 ch06.qxp 11/20/06 7:56 AM Page 134 Note that SQL Server Mobile changed the database file format, so if you have a database file created with SQL Server CE, you will need to upgrade the database file from the command-line utility that SQL Server Mobile provides. By default, this upgrade utility is located at C:\Program Files\Microsoft Visual Studio 8\SmartDevices\SDK\SQL Server\Mobie\v3.0\wce500\[processor]\ upgrade.exe . Assume the old database is oldDB.sdf located in the oldDir folder with a password of oldPass. To upgrade it to newDB.sdf in the newDir folder with the password newPass, use the following command: Upgrade.exe /s “oldDir\oldDB” /sp “oldPass” /d “newDir\newDB.sdf” /dp “newPass” SQL Server Mobile Architecture In a nutshell, SQL Server Mobile is a relational database that operates on a tiny runtime. As shown in Figure 6-1, the SQL Server Mobile architecture includes a development environment, a client environ- ment, and a server environment. Figure 6-1 The development environment, of course, is where you develop your applications. For SQL Server Mobile applications, only Visual Studio 2005 is supported as the development environment. The managed code you develop relies on the ADO.NET layer in the .NET Compact Framework to call into SQL Server Mobile. If you have to develop your application using unmanaged code, you can get access to SQL Server through an OLE database provider. Development Environment Visual Studio 2005 Managed Code ADO.NET SQL Server Mobile Client Environment Smart Device Application Deploy SQL Server Mobile Client Agent SQL Server Mobile TY 56 R 4 E 3 W 2 Q 1 G = F - D + S / A * V ? C ) X ( Z $ NUM CAP B ! P 0 O 9 I 8 U 7 M . N , L @ K " J ' H : SYMBOL SPACE 5:14 PM MESSAGES DEL Server Environment IIS Server SQL Server Mobile Client Agent HTTP SQL Server ActiveSync 135 Data Access with SQL Server Mobile 11_762935 ch06.qxp 11/29/06 3:24 PM Page 135 The client environment is the smart device. Typically, SQL Server Mobile is preinstalled on a Windows Mobile 5 device and emulator. When you deploy your application to the device, the corresponding SQL Server Mobile databases are also copied to the mobile device as files in .sdf format. The Smartphone user can then simply access the local copy of the database for regular data manipulations. A connection to the servers is required when users need to synchronize their local databases with the copies stored on the database servers. The server environment includes a Microsoft Internet Information Services (IIS) server, SQL Server Mobile Server Agent, and SQL Server. An IIS server is required in the server environment because the SQL Server Mobile Server Agent listens to the requests from the SQL Server Mobile Client Agent via HTTP requests. The SQL Server Mobile Client Agent can make such HTTP requests through either WiFi net- works or by the ActiveSync connections. The desktop version of SQL Server in the server environment enables users to replicate and synchronize data between SQL Server Mobile databases and SQL Server databases, which in turn offers full functionality to manage and analyze data. At the time of writing, Microsoft has announced SQL Server Everywhere Edition, which is very similar to SQL Server Mobile but it can be deployed not only to smart devices and Tablet PCs, but also to desk- top computers and servers. Installing SQL Server Mobile This subsection walks you through the procedures for installing the development environment, the client environment, and the server environment to make SQL Server Mobile functioning correctly. System Requirements Before installing SQL Server Mobile, you should determine whether your system meets the hardware and software prerequisites, as shown in Table 6-2. Note that the required components vary depending on your SQL Server Mobile device. Table 6-2 SQL Server Mobile System Requirements Environment Requirements Development Microsoft Visual Studio 2005 environment One of the following operating systems: Microsoft Windows Server 2003, Windows XP Media Center Edition, Win- dows XP Professional, Windows XP Tablet PC Edition, Windows 2000 Professional SP4 or later versions, or Windows 2000 Server SP4 or later versions Microsoft Internet Explorer 6.0 or later to access SQL Server Mobile Books Online Microsoft ActiveSync 4.0 or later to debug and deploy applications 136 Chapter 6 11_762935 ch06.qxp 11/20/06 7:56 AM Page 136 Environment Requirements Client environment Any device that runs Microsoft Windows CE 5.0, Microsoft Windows XP Tablet PC Edition, Windows Mobile 2003 Software for Pocket PC, or Windows Mobile 5.0 2 to 3MB storage space Server environment Microsoft SQL Server 2000 SP3a or later SQL Server 2005: Intel or compatible Pentium 600 megahertz (MHz) or greater processor required (1 GHz or greater recommended), 256MB RAM minimum (512MB RAM or more recommended), 250MB hard disk space. IIS 5.0 or later versions: Supported on 32-bit Windows Server 2003, 32-bit Windows XP, and Windows 2000 SP4; 120MB of available disk space on the server. Microsoft ActiveSync 4.0 or later versions are required to use Management Studio to manage SQL Server Mobile databases on connected devices. Microsoft Internet Explorer 6.0 or later Microsoft Outlook 98 or later is required for synchronization of e-mail, cal- endar, contacts, tasks, and notes to the desktop or portable computer (Out- look 2003 recommended). Installing the Development Environment If you have already installed SQL Server 2005, you don’t have to do anything. SQL Server Mobile files are already installed on the development computer. A number of classes in the System.Data .SqlServerCe namespace are available in the development environment to enable you to create databases and tables and to manipulate data in the databases. If the developing tool is Visual C++ for Devices or Embedded C++, you need to include the SsceOleDB.h, ca_mergex30.h, and Ssceerr30.h files in your projects. These header files and libraries provide APIs to access SQL Server Mobile through OLE DB connections. Installing the Server Environment A typical setting for the server environment enables data exchange between SQL Server and SQL Server Mobile. You need to install IIS, SQL Server 2005/2000 with Replication Components, and SQL Server Mobile Server Tools. If the IIS server and SQL Server are on different computers, make sure the SQL Server Mobile Server Tools are installed on the one that runs IIS. 137 Data Access with SQL Server Mobile 11_762935 ch06.qxp 11/20/06 7:56 AM Page 137 Installing the Client Environment As mentioned earlier, SQL Server Mobile is well integrated with Visual Studio 2005. When you deploy a managed application that interacts with SQL Server Mobile, Visual Studio will determine whether the software and components needed to run applications are installed on the device. If not, those compo- nents will be installed automatically to the smart device. By default, the installation path is \Windows on the device. You can use SQL Server Management Studio in SQL Server to manage the SQL Server Mobile databases. Things are little different if you need to deploy a native application. You need to manually copy SQL Server Mobile to the device. You may also want to copy the SQL Server Mobile Query Analyzer, which is a graphical management tool to manage SQL Server Mobile databases. Setting Up the SQL Server Mobile Server Environment In this section you will learn how to create and synchronize a SQL Server Mobile database. The process describes the most common scenario whereby a desktop version of SQL Server is running in the back- ground and SQL Server Mobile is running on mobile devices. The synchronization between the two is made available through a web interface. To begin, you need to install SQL Server Mobile Server Tools, which include the SQL Server Mobile Server Agent, the SQL Server Mobile Replication Provider, and the Configure Web Synchronization Wizard. This section assumes that you have already installed SQL Server 2005. Installing SQL Server Mobile Tools By default, Microsoft SQL Server Mobile Server Tools is not installed in SQL Server 2005. Navigate to C:\Program Files\Microsoft SQL Server\90\Tools\Binn\VSShell\Common7\IDE and find the setup program sqlce30setupen.msi. Double-click the program to open the SQL Server 2005 Mobile Server Tools Setup Wizard. You can easily finish installing the tool; the settings are self-explanatory. The only thing to note here is to make sure that the Synchronize with SQL Server 2005 option is checked. Creating a Database and Tables from SQL Server 2005 In the next step, you are going to create a database and a table from SQL Server. First, from the machine on which SQL Server is installed, click Start ➪Program➪Microsoft SQL Server 2005 and open SQL Server Management Studio. The Connect to Server Wizard appears, as indicated in Figure 6-2. Choose Database Engine as the server type and fill in the appropriate server name and authentication method of the server. When you are done, click the Connect button to connect to the SQL Server. 138 Chapter 6 11_762935 ch06.qxp 11/20/06 7:56 AM Page 138 Figure 6-2 Once the SQL Server is connected, you can create a new database. Right-click the Databases icon from Object Explorer in SQL Server Management Studio and choose New Database (see Figure 6-3). In the resulting New Database window, shown in Figure 6-4, name the database MyDB1. Figure 6-3 139 Data Access with SQL Server Mobile 11_762935 ch06.qxp 11/20/06 7:56 AM Page 139 Figure 6-4 Next, create a simple StuGrades table in the MyDB1 database by right-clicking the MyDB1 icon from Object Explorer in SQL Server Management Studio and choosing New Table. In the Table designer of SQL Server Management Studio, add StudentID and Grade as the Column names. The data type of StudentID is bigint and does not allow nulls, whereas the data type of Grade is smallint and can take nulls, as indicated in Figure 6-5. Once the table is created, it appears in the Object Explorer window, as shown in Figure 6-6. The table is created, but it is currently empty. In SQL Server Management Studio, you can add rows to a table in a SQL Server database. Right-click the table you want to edit and choose Open Table (see Figure 6-7). 140 Chapter 6 11_762935 ch06.qxp 11/20/06 7:56 AM Page 140 Figure 6-5 Figure 6-6 141 Data Access with SQL Server Mobile 11_762935 ch06.qxp 11/20/06 7:56 AM Page 141 Figure 6-7 Randomly add entries to the table, as shown in Figure 6-8. Figure 6-8 Now you have a simple database that contains a simple table, ready for action. In reality, the SQL Server database could be huge, and you certainly want the data stored in SQL Server to be easily replicated to a SQL Server Mobile database. To do that, you need to create a publication in a SQL Server database and then subscribe to this publication from the SQL Server Mobile database. Creating a Publication Before you create a publication, first ensure that SQL Server Agent, which appears in the bottom of the Object Explorer (see Figure 6-9), is currently running. If not, start it. 142 Chapter 6 11_762935 ch06.qxp 11/20/06 7:56 AM Page 142 [...]... the folder has a shared name of MyDB1 and a machine name of Spirit; therefore, the UNC path is \\spirit\MyDB1, as shown in Figure 6-16 145 11_762935 ch06.qxp 11/20/06 7:56 AM Chapter 6 Figure 6- 14 Figure 6-15 146 Page 146 11_762935 ch06.qxp 11/20/06 7:56 AM Page 147 Data Access with SQL Server Mobile Figure 6-16 Creating a SQL Server Mobile Database Now that the SQL server is set up and correctly configured,...11_762935 ch06.qxp 11/20/06 7:56 AM Page 143 Data Access with SQL Server Mobile Figure 6-9 Expand the Replication folder from the Object Explorer and then launch the New Publication Wizard by right-clicking the Local Publication icon and choosing New Publication, as shown in Figure 6-10 Figure 6-10 143 11_762935 ch06.qxp 11/20/06 7:56 AM Page 144 Chapter 6 Four types of publications are available... grade to 84 for the student who has an ID of 4 This is accomplished by first establishing a SqlCeConnection and then executing a SqlCeCommand object, as follows: private void updateArow() { SqlCeConnection ceConn = new SqlCeConnection(); SqlCeCommand ceCmd = new SqlCeCommand(); ceConn.Open(); ceCmd.Connection = ceConn; ceCmd.CommandText = “UPDATE StuGrades” + “SET grade = 84 + “WHERE StudentID = 4 ; ceCmd.ExecuteNonQuery;... technologies, it is fairly reasonable to expect support for those technologies in NET Compact Framework for Smartphone application development Win32 APIs to control Bluetooth are available in the Smartphone SDK Emulator Networking The Smartphone emulator implements the complete network stack of a Smartphone operating system Hence, it can access the network through its hosting desktop computer via ActiveSync... Page 1 54 Chapter 6 Figure 6-28 Figure 6-29 You are then asked if you would like to copy the database file to your Smartphone project, as shown in Figure 6-30 Because SQL Server Mobile uses the local data file, click Yes in the dialog box As shown in Figure 6-31, the Data Source Configuration Wizard will ask you to pick the database objects that you wanted included in the in-memory data set 1 54 11_762935... periodically Choose Merge publication (see Figure 6-11) and don’t forget to include SQL Server 2005 Mobile Edition in the Subscriber Types window (see Figure 6-12) Figure 6-11 144 Figure 6-12 11_762935 ch06.qxp 11/20/06 7:56 AM Page 145 Data Access with SQL Server Mobile Next you will be prompted to choose which tables to publish Check StuGrades from the Tables object, as shown in Figure 6-13 Figure 6-13... through a variety of networks 163 11_762935 ch06.qxp 11/20/06 7:56 AM Page 1 64 12_762935 ch07.qxp 11/20/06 7:56 AM Page 165 Networking This chapter introduces you to one of the most exciting parts of Smartphone software development: networking! We start with an overview of the networking support in the NET Compact Framework for Smartphone and then introduce topics ranging from application layer web access... SQL Server To begin, run the New Subscriptions Wizard and select Find SQL Server Publisher, as shown in Figure 6-19 and Figure 6-20, respectively 148 11_762935 ch06.qxp 11/20/06 7:56 AM Page 149 Data Access with SQL Server Mobile Figure 6-19 Figure 6-20 149 11_762935 ch06.qxp 11/20/06 7:56 AM Page 150 Chapter 6 During this process, you need to provide a URL to the SQL Server Mobile virtual directory... Server Mobile database To use APIs in this namespace, don’t forget to add a reference In Visual studio 2005, click Project➪Add reference and choose System.Data.SqlServerCe, as shown in Figure 6- 34 Figure 6- 34 Recall from our earlier discussion that GUI tools are used to create a database and tables and to add rows These steps can also be performed with the help of the SqlServerCe namespace To create... { SqlCeConnection ceConn = new SqlCeConnection(); SqlCeCommand ceCmd = new SqlCeCommand(); ceConn.Open(); ceCmd.Connection = ceConn; ceCmd.CommandText = “UPDATE StuGrades” + “SET grade = 84 + “WHERE StudentID = 4 ; ceCmd.ExecuteNonQuery; ceConn.Close(); } private void webSync() { SqlCeReplication repl = new SqlCeReplication(); repl.InternetUrl = @”http://192.168.0.88/MyDB1/sqlcesa30.dll”; repl.Publisher . 2000 Professional SP4 or later versions, or Windows 2000 Server SP4 or later versions Microsoft Internet Explorer 6.0 or later to access SQL Server Mobile Books Online Microsoft ActiveSync 4. 0. in Figure 6-16. 145 Data Access with SQL Server Mobile 11_762935 ch06.qxp 11/20/06 7:56 AM Page 145 Figure 6- 14 Figure 6-15 146 Chapter 6 11_762935 ch06.qxp 11/20/06 7:56 AM Page 146 Figure 6-16 Creating. (see Figure 6-7). 140 Chapter 6 11_762935 ch06.qxp 11/20/06 7:56 AM Page 140 Figure 6-5 Figure 6-6 141 Data Access with SQL Server Mobile 11_762935 ch06.qxp 11/20/06 7:56 AM Page 141 Figure 6-7 Randomly