Database Communica/on in Visual Studio/C# using Web Services. Hans- Pe=er Halvorsen, M.Sc.

Transcription

1 Database Communica/on in Visual Studio/C# using Web Services Hans- Pe=er Halvorsen, M.Sc.

2 Background We will use Web Services because we assume that the the App should be used on Internet outside the Firewall). The Database is located on a Server that has no direct access to the Internet. 2

3 SoKware Architecture 3- Tier: A way to structure your code into logical parts. Different devices or sokware modules can share the same code. Client- Server 2- Tier Web Services Good SoKware! 3- Tier Architecture n- Tier Web Services: A standard way to get data over a network/internet using standard Web protocols (HTTP, etc.) APIs API: Applica/on Programming Interface. Different devices or sokware modules can share the same code. Code once, use it many /mes

4 The database- centric style. Typically, the clients communicate directly with the database. A three- /er style, in which clients do not connect directly to the database. Web Services, etc. 4

5 Note! The different layers can be on the same computer (Logic Layers) or on different Computers in a network (Physical Layers) 3- /er/layer Architecture Presenta/on Tier Business Logic Tier Data Access Tier Data Source PL BL DAL Data Tier - DL Logic Tier 5

6 Why 3- Tier (N- Tier Architecture?) Flexible applica/ons Reusable code Code once, use many /mes Modularized You need only to change part of the code You can deploy only one part You can Test only one part Mul/ple Developers Different parts (Tiers) can be stored on different computers Different Pla\orms and Languages can be used etc. 6

7 h=p://en.wikipedia.org/wiki/mul//er_architecture 7

8 PresentaAon Tier 3- /er/layer Architecture This is the topmost level of the applica/on. The presenta/on /er displays informa/on related to such services as browsing merchandise, purchasing and shopping cart contents. It communicates with other /ers by which it puts out the results to the browser/client /er and all other /ers in the network. In simple terms it is a layer which users can access directly such as a web page, or an opera/ng systems GUI ApplicaAon Aer (business logic, logic Aer, data access Aer, or middle Aer) The logical /er is pulled out from the presenta/on /er and, as its own layer. It controls an applica/on s func/onality by performing detailed processing. Data Aer This /er consists of database servers. Here informa/on is stored and retrieved. This /er keeps data neutral and independent from applica/on servers or business logic. Giving data its own /er also improves scalability and performance. h=p://en.wikipedia.org/wiki/mul//er_architecture 8

9 3- /er Architecture Presenta/on Tier Presenta/on Tier Presenta/on Tier Different Devices can share the same Business and Data Access Code Business Logic Tier Data Access Tier Logic Tier The different Tiers can be physical or logical Stored Procedures Database Data Tier

10 3- /er + WebService Architecture - Example Installed on one or more Windows Servers in your LAN or in the Cloud Team Founda/on Server TFS Cient Web Server Web Services Business/ Data Logic Tier Data Source Stored Procedures Data Tier Team Founda/on Server Presenta/on Tier 10

11 3- /er Architecture Scenarios Client Client Internet Client Firewall Presenta/on Layer Presenta/on Layer Presenta/on Layer Client Client Web Service Presenta/on Layer Server Presenta/on Layer Presenta/on Layer Local Network (LAN) Business Logic Web Server Server Database Stored Procedures Data Access Logic

12 Client Client WinForms Client Android, ios, Windows 8/Windows Phone, etc. Client Web App Firewall Devices can share the same Business/Logic Tier and APIs Clients Presenta/on Tier ASP.NET Web Forms API Mobile Presenta/on Tier Desktop App App Seperate Presenta/on Tier PresentaAon Tiers for each Device App API API Business Tier Data Access Tier Web Service API Logic Tier e.g., ADO, ADO.NET Web Server Presenta/on Tier Internet Local Network 3- /er Architecture Scenarios Database Server Database Stored Procedures Views Tables Data Tier Note! The different Tiers can be on the same Computer (Logic Layers) or on different Computers in a network (Physical Layers)

13 Visual Studio Projects Solu/on with all Projects (Logic Tier, Web Service, Desktop App, Web App, Mobile App) Solu/on with Projects used by Web App (Logic Tier, Web App) 13

14 Data Tier We are going to create the Database / Data Layer/Tier, including: 1. Tables 2. Views 3. Stored Procedures 4. Triggers 5. Script for some Dummy Data Note! Install them in this order Download Zip Files with Tables, Views, Stored Procedures and Triggerse in order to create the Data Tier in SQL Server (The ZIP File is located on the same place as this File) 14

15 Data Tier Triggers Stored Procedures Views Tables Data Tier SQL Server 15

16 Database Tables 16

17 Execute the different Scripts inside SQL Server Management Studio 17

18 You are finished with the Exercise 18

19 Logic Tier ASP.NET Web Forms Presenta/on Tier WinForms Presenta/on Tier Windows Store App Presenta/on Tier Logic Tier Purpose: All the Apps should/could share the same Logic Tier To make your Apps easier to maintain and extend etc. Data Tier Database 19

20 Create an Empty (Blank) SoluAon in Visual Studio 20

21 Add Project for Logic Tier (Data Access) Select a Class Library Project LogicTier 21

22 Add a New Class to the Project ( StudentData.cs ) StudentData.cs 22

23 Create the Code, e.g., like this ( StudentData.cs ): Create your own Namespace A View that collects data from several tables Improvements: Use Try... Catch... 23

24 You should test the SQL Query in the SQL Server Management Studio first 24

25 Code ( StudentData.cs ): using System.Data.SqlClient; using System.Data.SqlTypes; using System.Data; namespace Tuc.School.LogicTier { public class StudentData { public DataSet GetStudentDB(string connectionstring) { string selectsql = "select StudentName, StudentNumber, SchoolName, ClassName, Grade from StudentData order by StudentName"; // Define the ADO.NET objects. SqlConnection con = new SqlConnection(connectionString); SqlDataAdapter da = new SqlDataAdapter(selectSQL, con); DataSet ds = new DataSet(); da.fill(ds); return ds; } } } 25

26 Create a proper name for the Assembly (.dll File) Right- click on the Project in the Solu/on Explorer and select Proper/es Then Build your Project (hopefully with no errors) This will be the Assembly for your Logic Tier, that can be imported and used in other projects. Create once use it many /mes!! 26

27 You are finished with the Exercise 27

28 Presenta/on Layer Desktop App: WinForms Using Web Services (we assume the The App should be used on Internet outside the Firewall) Label DataGridView 28

29 Step 1: Create Web Service Create an ASP.NET Project: SchoolWS SchoolWS.asmx Add Web Service: 29

30 Web Service Code Database Connec/onString is located in Web.config Web Service Method 30

31 Database Connec/onString is located in Web.config 31

32 Test Web Service Click to Test the Web Service Method we created It Works!! 32

33 Deploy/Publish Web Service to IIS Copy Web Service Files (Project) to default IIS Directory: C:\inetpub\wwwroot 33

34 34

35 Test if WS working: h=p://localhost/schoolws 35

36 Step 2: Use Web Service in WinForm Create New WinForm Project: WinFormAppWSClient 36

37 Add Web Service Reference Our Web Service Methods 37

38 Create GUI Label DataGridView

39 Create Code 39

40 WinForm Code using System.Windows.Forms; namespace WinFormAppWSClient { public partial class FormWSClient : Form { public FormWSClient() { InitializeComponent(); } private void FormWSClient_Load(object sender, EventArgs e) { FillStudentGrid(); } private void FillStudentGrid() { Call the Web Service method DataSet ds = new DataSet(); SchoolWSReference.SchoolWSSoapClient schoolws = new SchoolWSReference.SchoolWSSoapClient(); ds = schoolws.getstudent(); datagridviewstudentinformation.datasource = ds.tables[0]; } } Fill GridView 40

41 Test it: It works!!! 41

42 You are finished with the Exercise 42

43 Recommended Li=erature Tutorial: Introduc/on to Database Systems h=p://home.hit.no/~hansha/?tutorial=database Tutorial: Structured Query Language (SQL) h=p://home.hit.no/~hansha/?tutorial=sql Tutorial: Using SQL Server in C# Tutorial: Introduc/on to Visual Studio and C# h=p://home.hit.no/~hansha/?tutorial=csharp 43

44 Hans- PeUer Halvorsen, M.Sc. Telemark University College Faculty of Technology Department of Electrical Engineering, InformaAon Technology and CyberneAcs E- mail: Blog: hup://home.hit.no/~hansha/ 44