1. Using ADO.Net to Build a Login System Dr. Ron Eaglin

2. Lecture This lecture will take you step by step through using SQL Server 2005 to create a Database Driven login system. –Requires SQL Server 2005 –Requires Visual Studio 2005

3. Requirements Login and password information will be stored in a database. Users will be presented a login screen that will allow them to; –Create a user account –Authenticate a login

4. Steps 1. Design Overall System Architecture 2. Design Database to Meet Requirements 3. Design Software System to Meet Needs 4. Build 5. Test 6. Deploy

5. Design (Visio)

6. Enterprise Application (in Visio)

7. Create Diagram and Document Design

8. System Architecture Design

9. Database Design Must be able to –(1) Keep names for users –(2) Keep login names for users –(3) Store passwords for users –(4) Check validity of password –(5) Create new users –(6) Verify new login names do not conflict

10. Database Design

11. Create New Table

12. Table Design Set as Primary Key So must be unique Null passwords are Not allowed

13. Table Design

14. Stored Procedures Check if login is valid Add new user to database

15. New Stored Procedure

17. Parameter Template (Ctrl-Shift M)

18. Add NewUser Procedure CREATE PROCEDURE AddNewUser @LoginName nvarchar(50), @UserPassword nvarchar(30), @UserName nvarchar(200) AS BEGIN DECLARE @loginNameCount AS smallint SELECT @loginNameCount = COUNT(*) FROM dbo.UserLogin WHERE LoginName = @LoginName

19. AddNewUser Procedure IF @loginNameCount >= 1 BEGIN PRINT 'Login Name Already Exists in Database' RETURN END INSERT INTO dbo.UserLogin (LoginName, UserName, UserPassword) VALUES (@LoginName, @USerName, @UserPassword) END GO

20. Stored Procedure Click Execute

21. Test Stored Procedure

23. isLoginValid Function

24. IsUserValid CREATE FUNCTION isUserValid ( -- Add the parameters for the function here @LoginName nvarchar(50), @UserPassword nvarchar(30) ) RETURNS SMALLINT AS BEGIN DECLARE @Result SMALLINT SELECT @Result = COUNT(*) FROM dbo.UserLogin WHERE LoginName = @LoginName ANDUserPassword = @UserPassword RETURN @Result END GO

25. Test Function

26. UserValidResult Stored Procedure ALTER PROCEDURE [dbo].[UserValidResult] @LoginName nvarchar(50), @UserPassword nvarchar(30), @Result int output AS BEGIN select @Result=dbo.isUserValid(@LoginName,@UserPassword) END

27. Visual Studio 2005 Create Project

28. Windows Application We will create a Windows Application

29. Designer Page Form under construction Solution Explorer Properties of currently Selected object

30. VS Toolbox VS Toolbox contains all the objects That can be placed on the user form. In this example we will have a text box For the login name, the password, and A submit button.

31. Designing Form Place 2 labels (drag and drop From the toolbox, a text box And a masked text box on The form. Also drop a button. Line each of the items up.

32. Setting Properties Select Object Set Properties

33. Connecting to a Database

34. Connect to Database

35. Set Database Server Set Database within Server

36. Database Connection Connection info Will be in the Server explorer.

37. Code Window View Double click on Any object to Open a code Window.

38. Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim enteredUsername As String = Trim(TextBox1.Text) Dim enteredUserPassword As String = Trim(MaskedTextBox1.Text) Dim NumUsersFound As Integer Dim myConnection As New Data.SqlClient.SqlConnection myConnection.ConnectionString = "Data Source=WHITEWATER;Initial Catalog=CET4429;Integrated Security=True" Try myConnection.Open() Catch ex As Exception MsgBox("Could not open Connection", MsgBoxStyle.Information) Return End Try

39. Dim MyDataAdapter As New Data.SqlClient.SqlDataAdapter("UserValidResult", myConnection) MyDataAdapter.SelectCommand.CommandType = CommandType.StoredProcedure MyDataAdapter.SelectCommand.Parameters.Add(New Data.SqlClient.SqlParameter("@LoginName", _ SqlDbType.VarChar, 50)) MyDataAdapter.SelectCommand.Parameters.Add(New Data.SqlClient.SqlParameter("@UserPassword", _ SqlDbType.VarChar, 30)) MyDataAdapter.SelectCommand.Parameters.Add(New Data.SqlClient.SqlParameter("@Result", _ SqlDbType.Int, 4))

40. MyDataAdapter.SelectCommand.Parameters("@LoginName").Value = enteredUsername MyDataAdapter.SelectCommand.Parameters("@UserPassword").Value = enteredUserPassword MyDataAdapter.SelectCommand.Parameters("@Result").Direction = ParameterDirection.Output

41. Dim DS As New DataSet() 'Create a new DataSet to hold the records. MyDataAdapter.Fill(DS, "UserValidResult") 'Fill the DataSet with the rows returned NumUsersFound = CInt(MyDataAdapter.SelectCommand.Parameters("@Result").Value) If NumUsersFound = 0 Then MsgBox("No users found") Else MsgBox("Users found") End If myConnection.Close()

42. Results

44. Skill Summary User SQL Server 2005 Design and Create Tables Design and Create Application Create Stored Procedures and Functions Use Visual Studio Create a Windows Application Design a Form Use Database Object

45. Skill Summary Database Objects –Connection Object –Data Adapter –Parameter Objects –Data Set