CS 3870/CS 5870: Note05

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Web Application with Database

Master Page

• All Web pages will be similar

• Should be created before other web pages

• Add New Items

• Master Page

• Name: Prog3MasterPage.master

• Check “Place code in separate file”

• Uncheck “Select master page”– Could create a master page based on another master page

• May be incomplete and need to come back later

Elements on the Master page

• External CSS file<link href="StyleSheet.css" rel="stylesheet" type="text/css" />

• Form– All controls should be inside Form for dynamic pages

• Two ContentPlaceHolder controls: could change id

<asp:ContentPlaceHolder id="head" runat="server">

</asp:ContentPlaceHolder>

<asp:ContentPlaceHolder id="ContentPlaceHolder1"

runat="server">

</asp:ContentPlaceHolder>

Elements on the Master page

• Leave ContentPlaceHolder empty

• Add all common elements before/after ContentPlaceHolder– Title and Names

– Adding navbar: incomplete

Content Pages• Create the three pages using the master page

– Add New Item

– Web Form

– Place code in separate file

– Select master page

– Add

– Select folder

– Select Master page

• The second web form

– Add

– Web Form (with master)5

Content Pages• No Form control on content pages

– The form control on the master page will be combined with the controls on the content page

• Two Content controls

<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server"> </asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="Prog3Body" Runat="Server">

</asp:Content>

• Type it if not there6

Complete the Navbar on Master Page

<li> <a href="Default.aspx"> All Products </a></li>

<li> <a href="Updating.aspx"> Updating Products </a></li>

<li> <a href="Shopping.aspx"> Shopping </a></li>

Type and select the pages.

Adding Elements

• Type “All Products”, “Updating” and “Shopping” on the three pages

• Run IE to see the pages

The Database

• UWPCS3870

• SQL Server on Alpha

• User: MSCS

(not case sensitive)

• Password: MasterInCS

(case sensitive)

Table Product

Four Columns

ProductID : nchar(4), primary key,

not updatable

ProductNmae: nvarchar(50)

UnitPrice : smallmoney

Description : nvarchar(MAX), allow nulls

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)

• . . .

SQLDataClass

• Code class in folder App_Code

• No code module

• All variables and procedures should be

Shared (Static in C#, Java and C++)

• Otherwise, need to create object

Variables

Public Class SQLDataClass

Private Const ConStr As String = "Data Source=Alpha;” &

“Initial Catalog=UWPCS3870;Persist Security Info=True;” &

“User ID=MSCS;Password=MasterInCS"

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.

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

Retrieve Data Records‘ Gets the table records and the table schema

Public Shared Sub getAllProducts()

‘ Need to reset the command

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 16

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.

Setting up the AdapterPublic Shared Sub getAllProdcts()

If prodAdapter Is Nothing Then

setupProdAdapter()

End If

End Try

End Sub

Binding Gridview

‘ Add a GridView on page Default.aspx

‘ GridView: ToolBox – Data

Protected Sub Page_Load(. . .) Handles Me.Load

SQLDataClass.getAllProducts()

GridView1.DataSource = SQLDataClass.tblProduct

GridView1.DataBind()

End Sub

Refill the data table for each page request.

Formatting GridView<asp:GridView runat="server" ID="GridView1" AutoGenerateColumns="False"

style="z-index: 1; position: relative; width: 50%; margin-left:25%;

align-items: center; height: 176px" >

<asp:BoundField DataField="ProductID" HeaderText="Product ID" >

<asp:BoundField DataField="ProductName" HeaderText="Product Name" >

<asp:BoundField DataField="UnitPrice" HeaderText="Unit Price"

DataFormatString="{0:c}" HtmlEncode="False" >

<asp:BoundField DataField="Description" HeaderText="Description">

</Columns>

</asp:GridView>

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_”

Session Variables

Sub Session_Start(. . .)

Session(“Prog3_Index”) = 0

End Sub

Protected Sub Page_Load(…) Handles Me.Load

DisplayRow(Session("Prog3_Index"))

End Sub

Display RecordProtected Sub Page_Load(…) Handles Me.Load

DisplayRow(Session(“Prog3_Index”))

End Sub

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

Navigation Buttons

Partial Class Prog3_Updating

Protected Sub Button6_Click(…) Handles btnNext.Click

Session(“Prog3_Index”) += 1

End Sub

Protected Sub Button6_Click(…) Handles btnPrevious.Click

Session(“Prog3_Index”) -= 1

End Sub

Enable/Disable Buttons

Could make a private Sub.

Your choice.

Navigation Buttons

Protected Sub Button6_Click(…) Handles btnNext.Click

Session(“Prog3_Index”) += 1

EnableDisableButtons()

End Sub

Protected Sub Button6_Click(…) Handles btnPrevious.Click

Session(“Prog3_Index”) -= 1

EnableDisableButtons()

End Sub

Enable/Disable Buttons

Sub EnableDisableButtons()

if Session(“Prog3_Index”) = 0 Then

ElseIf Session(“Prog3_Index") =

SQLDataClass.tblProduct.Rows.Count - 1 Then

End If

End Sub

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’;

Button Update

‘ Page Updating.Aspx

‘ID not to be modified

Protected Sub Button6_Click(…) Handles btnUpdate.Click

‘Dim theID As String = txtID.Text

Dim oldID As String =

SQLDataClass.tblProduct.Rows(Session(“Prog3_Index"))(0)

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

UpdateProduct

‘ SQLDataClass

Public Shared Sub UpdateProduct(theID As String,

newName As String, newPrice As Double, newDesc As String)

‘ Building SQL statement with variables

prodCmd.CommandText = ". . ."

con.Open()

prodCmd.ExecuteNonQuery()

Catch ex

Throw ex

Finally

con.Close()

End Try

End Sub 30

UpdateProduct

‘ SQLDataClass

newName As String, newPrice As Double, newDesc As String)

prodCmd.CommandText =

" Update Product" & _

" Set ProductName = ‘newName', " & _

" UnitPrice = newPrice, " & _

" Description = ‘newDesc'" & _

" Where ProductID = 'theID‘”

End Try

End Sub

Incorrect! 31

UpdateProduct

‘ SQLDataClass

newName As String, newPrice As Double)

" Update Product " & _

" Set ProductName = " & newName & “, " & _

" UnitPrice = " & newPrice & ", " & _

" Description = " & newDesc & _

" Where ProductID = " & theID

End Try

End Sub

Incorrect! 32

UpdateProduct

‘ SQLDataClass

newName As String, newPrice As Double)

" Update Product " & _

" Set ProductName = '" & newName & "'," & _

" UnitPrice = " & newPrice & ", " & _

" Description = '" & newDesc & "'" & _

" Where ProductID = '" & theID & "'“

End Try

End Sub

Correct! 33

Try-Catch-FinallyPublic Shared Sub UpdateProduct(oldID As String,

newID As String, newName As String, newPrice As Double)

prodCmd.CommandText = ". . ."

con.Open()

prodCmd.ExecuteNonQuery() ‘ update database

Catch ex

Throw new Exception(ex.Message & “ ” &

prodCmd.CommandText)

Finally

con.Close() ‘ always close it

End Try

End Sub

Button Update

Protected Sub Button6_Click(…) Handles btnUpdate.Click

Dim . . .

DataClass.UpdateProduct(theID, newName,

newPrice, newDesc)

txtMsg.Text = "Record updated“

‘ must update tblProducts

SQLDataClass.getAllProduct()

Catch ex

txtMsg.Text = ex.Message ‘including myCmd.CommandText

End Try

End Sub 35

Updating

Inherits System.Web.UI.Page

txtMsg.Text = ""

DisplayRow(Session(“Prog3_Index"))

End Sub

Cannot Update Correctly!

Updating

txtMsg.Text = ""

End Sub

Cannot Update Correctly!

Post Back!

PostBack

txtMsg.Text = “”

If Not IsPostBack Then

‘ Do not do anything

‘ Textboxes keep their values from client

End If

End Sub

PostBack

txtMsg.Text = “”

‘ Else is not needed

If Not IsPostBack Then

End If

End Sub

Buttons

• btnNew– New– Save New

• btnDelete– Delete– Cancel

• Enabled/Disabled

CS 3870/CS 5870: Note05

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