1. Unit 8.2 How data can be used Accessing Data in Views
Learning Objectives
How data can be used
The Money Ball Example
Accessing Data in Views
Accessing data in Graphical Web Controls
Working with Templated Data
Working with Hidden Cells
Group Exercise

3. How Data can be used Example: Moneyball Batting average Stolen bases
Runs batted in
On-base %
Slugging %
On-base + Slugging (OPS)
How Data can be used

5. Databases Database creation and use Database and Query Development
MS Visual Web Developer
Database and Query Development
MS SQL Server
Business Intelligence
Microsoft BI, IBM Cognos
Real world Application
Money Ball

6. Collections of Rows
GridViews and DetailsViews contain a “collection” of Rows
Each Row contains a collection of Cells
Cells
Data bound controls are complex structures that contain/hold other controls, controls that are not visible from page level code
Before we can extract data from these internal controls we must locate them inside the control that is visible from the page
Rows
gvFees
dvFee

7. Locations of Cells DetailsView dvFee
DetailsView dvFee
The Fee amount (i.e )
dvFee.Rows[2].Cells[1]
GridView: gvFees ( “Select” is Column 0)
The FID of (i.e. 1) is in
gvFees.Rows[0].Cells[1]
The Weight Fee (i.e. 12.5) is in
gvFees.Rows[2].Cells[3] 1 2 1 2

8. Types of Cells: Standard and Templated
Standard cells
Templates
Come from Database
Yes, always
sometimes
Created manually
Never
Always in ItemTemplates
Data type
String
web control (e.g. DDL)
Used for
Display, edit
Insert, display, edit, validation
Accessed by
Cell Location
Cell Location + FindControl

9. Accessing Data in Standard CellsIf
The cell does NOT contain a CheckBox, AND
It has NOT been converted to a Template
Then
Your data is in the Text property of the Cell
Example:
Otherwise
Use the FindControl utility
Label lblFees = new Label();
lblFee.Text = gvFees.Rows[3].Cells[2].Text;
Label lblFees = gvFee.Rows[3].Cells[2].FindControl(“lblFee”) as Label;

10. Basic Templates Guidelines
To create/use templates, remember three things
Web control type (e.g. Label)
Its name (e.g. “lblFeeDescription”),
Its location (e.g. in ItemTemplates ).
Why use to Templates
To add validators
To insert new values into the database
To access the contents of a control in a template you first have to find it
All .NET controls that can hold other controls have a method called FindControl that allows you to locate the inner control
If FindControl locates the control it provides a link (sometimes called a pointer) to the control which we can capture in a variable
If you are looking in the wrong place, or misspell the control’s name FindControl won’t find it and will return a null value. You should ALWAYS test for this.

11. Template Example: DetailsView
To use templated data, convert them directly into labels.
Label lblDesc = dvFee.Rows[1].Cells[1].FindControl(lblDescription”) as Label

12. Hiding data in DetailViews

13. The Data is NOT where you think it is 1 2
dvFee.Rows[2].Cells[1] 1 2
Invisible field is still here
What is the location of the fee?

14. How to tell Examine at the “SelectedFields” window
Fee Description is still the second field (it is row 1)
And the Fee is still the third field (row 2) 1 2

15. Finding Data in GridViews
All Data is located in the row selected by the user
The SelectedIndex is used to index the row and is -1 if no row is selected
The basic idea is similar, except all the data for one record is in the same row and you have to know which row to use
If you only want data from the selected row, you can use the GridView’s SelectedIndex property – it tells you the number of the selected row (see next slide)

16. All rows of a GridView Use a special loop called “foreach”
Loops through a collection of rows
One row at a time
The type of object being extracted from the collection
The collection being looped through

17. Unit 8 L2
For this exercise we are going to modify your Unit 5 L2 assignment, replacing the fees ListBox with a fees GridView
Start by Opening your ASPPub and copying your yournameU5L2.aspx files into the Unit8 folder.
Rename the files to yournameU8L2
Change the page heading from UNIT 5 L2… to UNIT 8 L2 WORKING GRIDVIEW

18. Unit 8 L2 - 2
Delete the fees ListBox and put a GridView in its place. Give the GridView the (ID) of gvFees
Click on the GridView’s SmartMenu, click the dropdown next to Choose Data Source and select <New data source>
Select SQL Database and change its ID to sdsFees
Click OK and select the connection you created in U8L1

19. Unit 8 L2 - 3
Click Next, select the Fees table and select all the fields individually
Click Next and click Text Query to see the records in the table, then click Finish
Apply an Auto Format to the Gridview and change its width to 300px.
Select Edit Columns from the GridViews SmartMenu
Select TemplateField from Available Fields and press Add

20. Unit 8 L2 – 4
Click the Up Arrow key to move the TemplateField to the top of the Selected fields list
Select FID from Selected fields and change its Visible property to false
Select the FeeDescription field
change its HeaderText property to Description
Change its Styles, HeaderStyle, HorizontalAlign to Left
Select the Fee field and change its DataFormatString to {0:f2}

21. Unit 8 L2 - 5
Click OK and then EditTemplates, you should be looking at your new ItemTemplate
Add a CheckBox to the ItemTemplate
Change its (ID) to ckbSelect
Change its Text to Select
End Template Editing
You should have something that looks something like this

22. Unit 8 L2 - 6
Delete the WHILE loop button and all its associate code (the easiest way to do this may be do double-click the button to get to the code, select all the click method code and delete it, switch back to design view and delete the button)
Delete the FOR loop button and all its associate code
Double-click the sales tax button and locate and delete the code used in Unit 5 to process the ListBox (leave the lines that calculate the tax and those that write to the Label)

23. Unit 8 L2 - 7
In place of the ListBox code write a foreach loop to process the GridView rows:
Code: Find the CheckBox. Remember the data type & cast it (below)
Code: Is it Checked?
Code: Locate the Fee (remember, the invisible FID field still takes up a Cell!)
Code: add it to decFees
Wrap up
Sales tax and Switch statement is not critical for this Other than that, please make it look like the sample page …
Try A sales with no fees
Try A sales with one or more fees
foreach (GridViewRow gvRow in gvFees.Rows) { }

24. Unit 8 L2 - 8 Once you are sure that your calculations work
Add code to reset the checkboxes
This should be a foreach loop that
Locates the CheckBox in the GrideViewRow and
Sets its Checked property to false
Test the page with the same data as before to be sure you get the same answers and that the checkboxes are reset
Once you are sure the page works, link it to your MIS3200 profile page and save your complete ASPPub to ASPNET as you have done before
Post a link to your MIS3200 portfolio page in the dropbox

25. Think About It!
A DetailsView and a GridView always look like tables. Think of some applications where you might want to display data in a different way.
A FormView shows one record at a time, like the DetailsView, but it isn’t divided into Rows and Cells. How do you think you would access data in a FormView.