1 CS 3870/CS 5870: Note05 Prog3 Web Application with Database

2 Master Page All Web pages will be similar Should be created before other web pages Add New Items Master Page Check “Place code in separate file” Uncheck “Select master page” –Could create a master page based on another master page May be incomplete

3 Controls on the Master page Form –All controls should be inside Form for dynamic pages Two ContentPlaceHolder controls One in and one in Leave ContentPlaceHolder empty Add controls before/after ContentPlaceHolder –Title and Names –Adding navbar –External CSS file

4 CSS File body { padding-left: 12em; }.navbar { list-style-type: none; padding: 0; margin: 0; position: absolute; top: 4em; left: 1em; width: 11em }

5 Navbar All Products Updating Products Shopping No links yet!

Content Pages Create the three pages using the master page –Web Form (with master) –Select master page –Make sure selecting folder first No Form control on content pages Control Content –ContentPlaceHolderID references ContentPlaceHolder control on master page –Could be empty for 6

7 Complete the Navbar on Master Page All Products Updating Products Shopping

8 The Database UWPCS3870 SQL Server Express on Xray User: jim (not case sensitive) Password: UWPCS3870 (case sensitive)

Table Product Four Columns ProductID : nchar(3), primary key, not updatable ProductNmae: nvarchar(50) UnitPrice : smallmoney Description : nvarchar(MAX), allow nulls 9

10 Accessing Database Data Source Controls –SqlDataSource –AccessDataSource –... Code class –Connection –Command –DataAdpater –AdapterBuilder Prog3 –Use Code class

ASP.NET Folders Solution Explorer Right click Web site Add ASP.NET Folder App_Code (App_Data)... 11

SQLDataClass Code class in folder App_Code No code module All variables and procedures should be Shared Otherwise, need to create object 12

Variables Public Class SQLDataClass Private Const ConStr As String = "Data Source=Xray\Sqlexpress;” & “Initial Catalog=UWPCS3870;Persist Security Info=True;” & “User ID=jim;Password=UWPCS3870" Private Shared prodAdapter As System.Data.SqlClient.SqlDataAdapter Private Shared prodBuilder As System.Data.SqlClient.SqlDataAdapter Private Shared prodCmd As New Data.SqlClient.SqlCommand Private Shared con As New Data.SqlClient.SqlConnection Public Shared tblProduct As New Data.DataTable("Product")... End Class The objects are available all the times. 13

Setup Command and Adapter ‘ Sets up the connection, command and adapter Public Shared Sub setupProdAdapter() con.ConnectionString = ConStr prodCmd.Connection = con prodCmd.CommandType = Data.CommandType.Text prodCmd.CommandText = "Select * from Product order by ProductID" prodAdapter = New System.Data.SqlClient.SqlDataAdapter(prodCmd) prodAdapter.FillSchema(tblProduct, Data.SchemaType.Source) End Sub 14

Retrieve Data Records ‘ Gets the table records and the table schema Public Shared Sub getAllProdcts() ‘ Need to reset the command prodCmd.CommandText = "Select * from Product order by ProductID" Try If Not tblProduct Is Nothing Then tblProduct.Clear() End If prodAdapter.Fill(tblProduct) Catch ex As Exception Throw ex Finally con.Close() End Try End Sub 15

Setting up the Adapter ‘ Global.asax Sub Application_Start(...) SQLDataClass.setupProdAdapter() End Sub Do it just once for the application for all sessions of all users. 16

Binding Gridview Protected Sub Page_Load(...) Handles Me.Load DataClass.getAllProducts() GridView1.DataSource = DataClass.tblProducts GridView1.DataBind() End Sub Refill the data table for each page request. 17

Page Updating Display record one at a time Display the first record for the first visit Display the same record for return visit Need Session variable Begin with “Prog3_” 18

Session Variables Sub Session_Start(...) Session(“Prog3_Index”) = 0 End Sub Protected Sub Page_Load(…) Handles Me.Load DisplayRow(Session(“Prog3_Index”)) End Sub 19

Display Record Private Sub DisplayRow(Index As Integer) Dim row As Data.DataRow row = SQLDataClass.tblProduct.Rows(index) ‘ May need formatting txtID.Text = row(0) txtName.Text = row(1) txtPrice.Text = row(2) txtDescription.Text = row(3) End Sub 20

Navigation Buttons Partial Class Prog3_Updating Protected Sub Button6_Click(…) Handles btnNext.Click Session(“Prog3_Index”) += 1 DisplayRow(Session(“Prog3_Index”)) End Sub Protected Sub Button6_Click(…) Handles btnPrevious.Click Session(“Prog3_Index”) -= 1 DisplayRow(Session(“Prog3_Index”)) End Sub 21

Enable/Disable Buttons Could make a private Sub. Your choice. 22

Navigation Buttons Partial Class Prog3_Updating Protected Sub Button6_Click(…) Handles btnNext.Click Session(“Prog3_Index”) += 1 DisplayRow(Session(“Prog3_Index”)) EnableDisableButtons() End Sub Protected Sub Button6_Click(…) Handles btnPrevious.Click Session(“Prog3_Index”) -= 1 DisplayRow(Session(“Prog3_Index”)) EnableDisableButtons() End Sub 23

SQL Statements Update Product Set ProductName = ‘NewName’, UnitPrice = newPrice Description = ‘NewDescription’, Where ProductID = ‘theID’; Insert Into Product Values(‘ID’, ‘Name’, Price, ‘Description’); Delete From Product Where ProductID = ‘theID’; 24

Button Update ‘ID not to be modified Protected Sub Button6_Click(…) Handles btnUpdate.Click Dim theID As String = txtID.Text Dim newName As String = txtName.Text Dim newPrice As Double = txtPrice.Text Dim newDesc As String = txtDesc.Text SQLDataClass.UpdateProduct(theID, newName, newPrice, newDesc) End Sub 25

UpdateProduct Public Shared Sub UpdateProduct(theID As String, newName As String, newPrice As Double, newDesc As String) ‘ Building SQL statement with variables prodCmd.CommandText = "..." Try con.Open() prodCmd.ExecuteNonQuery() Catch ex Throw ex Finally con.Close() End Try End Sub 26

UpdateProduct Public Shared Sub UpdateProduct(theID As String, newName As String, newPrice As Double, newDesc As String) prodCmd.CommandText = " Update Product" & _ " Set ProductName = ‘newName', " & _ " UnitPrice = newPrice, " & _ " Description = ‘newDesc'" & _ " Where ProductID = 'theID‘” Try... End Try End Sub 27

UpdateProduct Public Shared Sub UpdateProduct(theID As String, newName As String, newPrice As Double) ‘ Building SQL statement with variables prodCmd.CommandText = " Update Product " & _ " Set ProductName = " & newName & “, " & _ " UnitPrice = " & newPrice & ", " & _ " Description = " & newDesc & _ " Where ProductID = " & theID Try... End Try End Sub 28

UpdateProduct Public Shared Sub UpdateProduct(theID As String, newName As String, newPrice As Double) ‘ Building SQL statement with variables prodCmd.CommandText = " Update Product " & _ " Set ProductName = '" & newName & "'," & _ " UnitPrice = " & newPrice & ", " & _ " Description = '" & newDesc & "'" & _ " Where ProductID = '" & theID & "'“ Try... End Try End Sub 29

Try-Catch Public Shared Sub UpdateProduct(oldID As String, newID As String, newName As String, newPrice As Double) prodCmd.CommandText = "..." Try con.Open() prodCmd.ExecuteNonQuery() con.Close() Catch ex ‘ To see what is wrong Throw ex(prodCmd.CommandText) End Try End Sub 30

Try-Catch-Finally Public Shared Sub UpdateProduct(oldID As String, newID As String, newName As String, newPrice As Double) prodCmd.CommandText = "..." Try con.Open() prodCmd.ExecuteNonQuery()‘ update database Catch ex Throw new Exception(ex.Message & “ ” & myCmd.CommandText) Finally con.Close()‘ always close it End Try End Sub 31

Button Update Protected Sub Button6_Click(…) Handles btnUpdate.Click Dim... Try DataClass.UpdateProduct(theID, newName, newPrice, newDesc) ‘ must update tblProducts SQLDataClass.getAllProduct() Catch ex txtMsg.Text = ex.Message ‘including myCmd.CommandText Finally con.Close()‘ always close it End Try End Sub 32

33 Updating Partial Class Prog3_Updating Inherits System.Web.UI.Page Protected Sub Page_Load(...) Handles Me.Load txtMsg.Text = "" DisplayRow(Session(“Prog3_Index")) End Sub Cannot Update Correctly!

34 Updating Partial Class Prog3_Updating Inherits System.Web.UI.Page Protected Sub Page_Load(...) Handles Me.Load txtMsg.Text = "" DisplayRow(Session(“Prog3_Index")) End Sub Cannot Update Correctly! Post Back!

35 PostBack Partial Class Prog3_Updating Inherits System.Web.UI.Page Protected Sub Page_Load(...) Handles Me.Load txtMsg.Text = “” If Not IsPostBack Then DisplayRow(Session(“Prog3_Index")) Else ‘ Do not do anything ‘ Textboxes keep their values from client End If End Sub

Buttons btnNew –New –Save New btnDelete –Delete –Cancel Enabled/Disabled 36