Data Base Connectivity

8/13/2019 Data Base Connectivity

1/25

DATA BASE CONNECTIVITY

What is ADO.NET?

ADO.NET is a part of the .NET Framework

ADO.NET consists of a set of classes used to handle data access

ADO.NET is entirely based on XM

ADO.NET has! unlike ADO! no "ecordset ob#ect

Create a Database Connection

$e are %oin% to use the Northwind database in our e&amples.

First! import the '(ystem.Data.OleDb' namespace. $e need this namespace to work with MicrosoftAccess and other OE D) database pro*iders. $e will create the connection to the database in the

+a%e,oad subroutine. $e create a dbconn *ariable as a new OleDb-onnection class with aconnection strin% which identifies the OE D) pro*ider and the location of the database. Then weopen the database connection

sub Page!oaim bconnbconn=Ne# OleDb$onnection"Provier=&icroso't.(et.O!)D*.+.,-ata source=" server.mappat/"nort/#in.mb"00bconn.Open0en sub

Note:The connection strin% must be a continuous strin% without a line break/

Create a Database Command

To specify the records to retrie*e from the database! we will create a dbcomm *ariable as a newOleDb-ommand class. The OleDb-ommand class is for issuin% (0 1ueries a%ainst database tables

sub Page!oaim bconn2s3l2bcommbconn=Ne# OleDb$onnection"Provier=&icroso't.(et.O!)D*.+.,-ata source=" server.mappat/"nort/#in.mb"00

bconn.Open0s3l="S)!)$4 5 67O& customers"bcomm=Ne# OleDb$ommans3l2bconn0en sub

Create a DataReader


2/25

The OleDbData"eader class is used to read a stream of records from a data source. A Data"eader iscreated by callin% the E&ecute"eader method of the OleDb-ommand ob#ect

sub Page!oaim bconn2s3l2bcomm2breabconn=Ne# OleDb$onnection"Provier=&icroso't.(et.O!)D*.+.,-ata source=" server.mappat/"nort/#in.mb"00bconn.Open0s3l="S)!)$4 5 67O& customers"bcomm=Ne# OleDb$ommans3l2bconn0brea=bcomm.)8ecute7eaer0en sub

Bind to a Repeater Control

Then we bind the Data"eader to a "epeater control

Example

sub Page!oaim bconn2s3l2bcomm2breabconn=Ne# OleDb$onnection"Provier=&icroso't.(et.O!)D*.+.,-ata source=" server.mappat/"nort/#in.mb"00bconn.Open0s3l="S)!)$4 5 67O& customers"bcomm=Ne# OleDb$ommans3l2bconn0brea=bcomm.)8ecute7eaer0customers.DataSource=breacustomers.Data*in0brea.$lose0bconn.$lose0en sub


3/25


4/25

Stanar :eaer 6or ll Pages

The master pa%e abo*e is a normal 4TM pa%e desi%ned as a template for other pa%es.

The @ Masterdirecti*e defines it as a master pa%e.

The master pa%e contains a placeholder ta%


5/25


6/25

Code Example:

The


7/25

Tips 5f the (iteMap+ath displays incorrectly! most likely there is an =" error 2typo3 in theweb.sitemap file.

Code Example:

The


8/25

The basics of ser*er side scriptin% like A(+ or +4+

5f you want to study these sub#ects first! find the tutorials on our 4ome +a%e

What is Classic A!P?

Microsofts pre*ious ser*er side scriptin% technolo%y A(+ 2Acti*e (er*er +a%es3 is now often calledclassic A(+.

A(+ B.; was the last *ersion of classic A(+.

To learn more about classic A(+! you can study our A(+ tutorial.

A!P.NET is NOT A!P

A(+.NET is the ne&t %eneration A(+! but its not an up%raded *ersion of A(+.

A(+.NET is an entirely new technolo%y for ser*er?side scriptin%. 5t was written from the %round upand is not backward compatible with classic A(+.

Cou can read more about the differences between A(+ and A(+.NET in the ne&t chapter of thistutorial.

A(+.NET is the ma#or part of the Microsofts .NET Framework.

What is A!P.NET?

A(+.NET is a ser*er side scriptin% technolo%y that enables scripts 2embedded in web pa%es3 to bee&ecuted by an 5nternet ser*er.

A(+.NET is a Microsoft Technolo%y

A(+ stands for Acti*e (er*er +a%es

A(+.NET is a pro%ram that runs inside 55(

55( 25nternet 5nformation (er*ices3 is Microsofts 5nternet ser*er

55( comes as a free component with $indows ser*ers

55( is also a part of $indows :;;; and X+ +rofessional

What is an A!P.NET #ile?

An A(+.NET file is #ust the same as an 4TM file

An A(+.NET file can contain 4TM! XM! and scripts

(cripts in an A(+.NET file are e&ecuted on the ser*er

An A(+.NET file has the file e&tension '.asp&'

(o' Does A!P.NET Wor)?

$hen a browser re1uests an 4TM file! the ser*er returns the file

$hen a browser re1uests an A(+.NET file! 55( passes the re1uest to the A(+.NET en%ine on

the ser*er

The A(+.NET en%ine reads the file! line by line! and e&ecutes the scripts in the file
http://www.w3schools.com/default.asphttp://www.w3schools.com/asp/default.asphttp://www.w3schools.com/default.asphttp://www.w3schools.com/asp/default.asp


9/25

Finally! the A(+.NET file is returned to the browser as plain 4TM

What is A!P*?

A(+> is the same as A(+.NET.

A(+> is #ust an early name used by Microsoft when they de*eloped A(+.NET.

The Microso+t .NET #rame'or)

The .NET Framework is the infrastructure for the Microsoft .NET platform.

The .NET Framework is an en*ironment for buildin%! deployin%! and runnin% $eb applications and$eb (er*ices.

Microsofts first ser*er technolo%y A(+ 2Acti*e (er*er +a%es3! was a powerful and fle&ible'pro%rammin% lan%ua%e'. )ut it was too code oriented. 5t was not an application framework and not

an enterprise de*elopment tool.

The Microsoft .NET Framework was de*eloped to sol*e this problem.

.NE) /ramewor0s 0eywords:

Easier and 1uicker pro%rammin%

"educed amount of code

Declarati*e pro%rammin% model

"icher ser*er control hierarchy with e*ents

ar%er class library

)etter support for de*elopment tools

)he .NE) /ramewor0 onsists of 1 main parts:

+ro%rammin% lan%ua%es

- 2+ronounced - sharp3


10/25

A!P.NET ,.-

A(+.NET :.; impro*es upon A(+.NET by addin% support for se*eral new features.

Cou can read more about the differences between A(+.NET :.; and A(+.NET in the ne&t chapter of

this tutorial.

A!P.NET .-

A(+.NET B.; is not a new *ersion of A(+.NET. 5ts #ust the name for a new A(+.NET :.; framework

library with support for $indows +resentation Foundation! $indows -ommunication Foundation!$indows $orkflow Foundation and $indows -ard(pace.

A(+.NET B.; is not co*ered in this tutorial.

A!P.NET "s. A!P

,'P.NE) has better language support2 a large set of new ontrols2 3M45basedomponents2 and better user authentiation.

,'P.NE) provides inreased performane by running ompiled ode.

,'P.NE) ode is not fully ba0ward ompatible with ,'P.

Ne' in A!P.NET

)etter lan%ua%e support

+ro%rammable controls E*ent?dri*en pro%rammin%

XM?based components

=ser authentication! with accounts and roles

4i%her scalability

5ncreased performance ? -ompiled code

Easier confi%uration and deployment

Not fully A(+ compatible

/ang%age !%pport

A(+.NET uses ADO.NET.

A(+.NET supports full .

A(+.NET supports @(cript.
http://www.w3schools.com/ASPNET/aspnet_install.asphttp://www.w3schools.com/ASPNET/aspnet_intro.asp


11/25

A!P.NET Controls

A(+.NET contains a lar%e set of 4TM controls. Almost all 4TM elements on a pa%e can be definedas A(+.NET control ob#ects that can be controlled by scripts.

A(+.NET also contains a new set of ob#ect?oriented input controls! like pro%rammable list?bo&es and

*alidation controls.

A new data %rid control supports sortin%! data pa%in%! and e*erythin% you can e&pect from adataset control.

E"ent A'are Controls

All A(+.NET ob#ects on a $eb pa%e can e&pose e*ents that can be processed by A(+.NET code.

oad! -lick and -han%e e*ents handled by code makes codin% much simpler and much betteror%aniGed.

A!P.NET Components

A(+.NET components are hea*ily based on XM. ike the new AD "otator! that uses XM to store

ad*ertisement information and confi%uration.

0ser A%thentication

A(+.NET supports form?based user authentication! cookie mana%ement! and automatic redirectin%

of unauthoriGed lo%ins.

0ser Acco%nts and Roles

A(+.NET allows user accounts and roles! to %i*e each user 2with a %i*en role3 access to different

ser*er code and e&ecutables.

(igh !calabilit$

Much has been done with A(+.NET to pro*ide %reater scalability.

(er*er?to?ser*er communication has been %reatly enhanced! makin% it possible to scale anapplication o*er se*eral ser*ers. One e&ample of this is the ability to run XM parsers! X(

transformations and e*en resource hun%ry session ob#ects on other ser*ers.

Compiled Code

The first re1uest for an A(+.NET pa%e on the ser*er will compile the A(+.NET code and keep a

cached copy in memory. The result of this is %reatly increased performance.

Eas$ Con+ig%ration


12/25

-onfi%uration of A(+.NET is done with plain te&t files.

-onfi%uration files can be uploaded or chan%ed while the application is runnin%. No need to restartthe ser*er. No more metabase or re%istry puGGle.

Eas$ Deplo$ment

No more ser*er?restart to deploy or replace compiled code. A(+.NET simply redirects all new

re1uests to the new code.

Compatibilit$

A(+.NET is not fully compatible with earlier *ersions of A(+! so most of the old A(+ code will need

some chan%es to run under A(+.NET.

To o*ercome this problem! A(+.NET uses a new file e&tension '.asp&'. This will make A(+.NETapplications able to run side by side with standard A(+ applications on the same ser*er.

,'P.NE) is easy to install. 6ust follow the instrutions below.

What 1o% Need

A Windo's Comp%ter

A(+.NET is a Microsoft technolo%y. To run A(+.NET you need a computer capable of runnin%$indows.

Windo's ,--- or 2P

5f you are serious about de*elopin% A(+.NET applications you should install $indows :;;;+rofessional or $indows X+ +rofessional.

5n both cases! make sure you install the 5nternet 5nformation (er*ices 255(3 from the Add"emo*e$indows components dialo%.

!er"ice Pac)s and 0pdates

)efore A(+.NET can be installed on your computer! it is necessary to ha*e all rele*ant ser*ice packsand security updates installed.

The easiest way to do this is to acti*ate your $indows 5nternet =pdate. $hen you access the$indows =pdate pa%e! you will be instructed to install the latest ser*ice packs and all critical

security updates. For $indows :;;;! make sure you install (er*ice +ack :. 5 will also recommendthat you install 5nternet E&plorer H.

"ead the note about connection speed and download time at the bottom of this pa%e.

Remo"e 1o%r Beta &ersion

5f you ha*e a )eta *ersion of A(+.NET installed! we recommend that you completely uninstall it. Or

e*en better start with a fresh $indows :;;; or X+ installation.


13/25

3nstall .NET

From your $indows =pdate you can now select to install the Microsoft .NET Framework.

After download! the .NET framework will install itself on your computer ? there are no options to

select for installation.

7ou should now be ready to develop your first ,'P.NE) appliation8

The .NET !o+t'are De"elopment 4it

5f you ha*e the necessary bandwidth to download o*er 7B; M)! you mi%ht consider downloadin% thefull Microsoft .NET (oftware De*elopment Iit 2(DI3.

$e fully recommend %ettin% the (DI for learnin% more about .NET and for the documentation!samples! and tools included.

Connection !peed and Do'nload Time

5f you ha*e a slow 5nternet connection! you mi%ht ha*e problems downloadin% lar%e files like theser*ice packs! the (DI and the latest *ersion of 5nternet E&plorer.

5f download speed is a problem! our best su%%estion is to %et the latest files from someone else!from a collea%ue! from a friend! or from one of the -Ds that comes with many popular computer

ma%aGines. ook for $indows :;;; (er*ice +ack :! 5nternet E&plorer H! and the Microsoft .NETFramework

(ello W!chools in A!P.NET

The simplest way to con*ert an 4TM pa%e into an A(+.NET pa%e is to copy the 4TM file to a newfile with an .aspxe&tension.

This code displays our e&ample as an A(+.NET pa%e

:ello ?Sc/oolsG

5f you want to try it yourself! sa*e the code in a file called 'firstpage.aspx'! and create a link tothe file like this firstpa%e.asp&

(o' Does it Wor)?

Fundamentally an A(+.NET pa%e is #ust the same as an 4TM pa%e.
http://www.w3schools.com/ASPNET/firstpage.aspxhttp://www.w3schools.com/ASPNET/firstpage.aspx


14/25

An 4TM pa%e has the e&tension .htm. 5f a browser re1uests an 4TM pa%e from the ser*er! theser*er sends the pa%e to the browser without any modifications.

An A(+.NET pa%e has the e&tension .asp&. 5f a browser re1uests an A(+.NET pa%e! the ser*erprocesses any e&ecutable code in the pa%e! before the result is sent back to the browser.

The A(+.NET pa%e abo*e does not contain any e&ecutable code! so nothin% is e&ecuted. 5n the ne&te&amples we will add some e&ecutable code to the pa%e to demonstrate the difference between

static 4TM pa%es and dynamic A(+ pa%es.

Classic A!P

Acti*e (er*er +a%es 2A(+3 has been around for se*eral years. $ith A(+! e&ecutable code can beplaced inside 4TM pa%es.

+re*ious *ersions of A(+ 2before A(+ .NET3 are often called -lassic A(+.

A(+.NET is not fully compatible with -lassic A(+! but most -lassic A(+ pa%es will work fine asA(+.NET pa%es! with only minor chan%es.

5f you want to learn more about -lassic A(+! please *isit our A(+ Tutorial.

D$namic Page in Classic A!P

To demonstrate how A(+ can display pa%es with dynamic content! we ha*e added some e&ecutable

code 2in red3 to the pre*ious e&ample

:ello ?Sc/oolsG

The code inside the 8J ??J9 ta%s is e&ecuted on the ser*er.

"esponse.$rite is A(+ code for writin% somethin% to the 4TM output stream.

Now23 is a function returnin% the ser*ers current date and time.

5f you want to try it yourself! sa*e the code in a file called 'dynpage.asp'! and create a link to thefile like this dynpa%e.asp

D$namic Page in A!P .NET

This followin% code displays our e&ample as an A(+.NET pa%e
http://www.w3schools.com/asp/default.asphttp://www.w3schools.com/ASPNET/dynpage.asphttp://www.w3schools.com/asp/default.asphttp://www.w3schools.com/ASPNET/dynpage.asp


15/25

:ello ?Sc/oolsG

5f you want to try it yourself! sa*e the code in a file called 'dynpage.aspx'! and create a link to thefile like this dynpa%e.asp&

A!P.NET "s Classic A!P

The pre*ious e&amples didnt demonstrate any differences between A(+.NET and -lassic A(+.

As you can see from the two latest e&amples there are no differences between the two A(+ and

A(+.NET pa%es.

5n the ne&t chapters you will see how ser*er controls make A(+.NET more powerful than -lassicA(+.

'erver ontrols are tags that are understood by the server.

/imitations in Classic A!P

The listin% below was copied from the pre*ious chapter

:ello ?Sc/oolsG

The code abo*e illustrates a limitation in -lassic A(+ The code block has to be placed where youwant the output to appear.

$ith -lassic A(+ it is impossible to separate e&ecutable code from the 4TM itself. This makes thepa%e difficult to read! and difficult to maintain.

A!P.NET 5 !er"er Controls

A(+.NET has sol*ed the 'spa%hetti?code' problem described abo*e with ser*er controls.

(er*er controls are ta%s that are understood by the ser*er.

There are three kinds of ser*er controls
http://www.w3schools.com/ASPNET/dynpage.aspxhttp://www.w3schools.com/ASPNET/dynpage.aspx


16/25

4TM (er*er -ontrols ? Traditional 4TM ta%s

$eb (er*er -ontrols ? New A(+.NET ta%s

Fisit ?Sc/oolsG


17/25

5n the followin% e&ample we declare a )utton ser*er control in an .asp& file. Then we create ane*ent handler for the -lick e*ent which chan%es the te&t on the button

Sub submitSource s Obect2 e s )ventrgs0button;.4e8t="Jou clicHe meG")n Sub

A!P.NET 5 &alidation !er"er Controls


18/25

$ontrol4oFaliate="tbo8;"&inimumFalue=";"&a8imumFalue=";,,"4ype="Integer"4e8t="4/e value must be 'rom ; to ;,,G"runat="server" 1>


19/25


20/25

Note:The form is always submitted to the pa%e itself. 5f you specify an action attribute! it isi%nored. 5f you omit the method attribute! it will be set to method6'post' by default. Also! if you donot specify the name and id attributes! they are automatically assi%ned by A(+.NET.

Note:An .asp& pa%e can only contain ONE 8form runat6'ser*er'9 control/

5f you select *iew source in an .asp& pa%e containin% a form with no name! method! action! or id

attribute specified! you will see that A(+.NET has added these attributes to the form. 5t lookssomethin% like this

!%bmitting a #orm

A form is most often submitted by clickin% on a button. The )utton ser*er control in A(+.NET hasthe followin% format

The id attribute defines a uni1ue name for the button and the te&t attribute assi%ns a label to the

button. The on-lick e*ent handler specifies a named subroutine to e&ecute.

5n the followin% e&ample we declare a )utton control in an .asp& file. A button click runs asubroutine which chan%es the te&t on the button

A!P .NET Maintaining the &ie'!tate

7ou may save a lot of oding by maintaining the *iew'tate of the ob9ets in your eb/orm.

Maintaining the &ie'!tate

$hen a form is submitted in classic A(+! all form *alues are cleared. (uppose you ha*e submitteda form with a lot of information and the ser*er comes back with an error. Cou will ha*e to %o back

to the form and correct the information. Cou click the back button! and what happens.......Aform *alues are -EA"ED! and you will ha*e to start all o*er a%ain/ The site did not maintain your


21/25

all form *alues. 4ow comeK This is because A(+ .NET maintains your

Maintainin% the


22/25

Sub submitsener s Obect2 e s )ventrgs0lbl;.4e8t=":ello " t8t;.4e8t "G")n Sub

)he )ext;ox ontrol is used to reate a text box where the user an input text.

The TetBo Control

The Te&t)o& control is used to create a te&t bo& where the user can input te&t.

The Te&t)o& controls attributes and properties are listed in our web controls reference pa%e.

The e&ample below demonstrates some of the attributes you may use with the Te&t)o& control

Example


23/25

4e8t*o8 #it/ /eig/t9

4e8t*o8 #it/ #it/9

)nter your name9


24/25

Example

Sub c/angesener s Obect2 e s )ventrgs0lbl;.4e8t="Jou c/ange te8t to " t8t;.4e8t)n Sub

e may use data binding to fill lists with seletable items from an imported data soure2li0e a database2 an 3M4 file2 or a sript.

Data Binding

The followin% controls are list controls which support data bindin%

asp"adio)uttonist asp-heck)o&ist

aspDropDownist

aspistbo&

The selectable items in each of the abo*e controls are usually defined by one or more aspist5temcontrols! like this


25/25

4owe*er! with data bindin% we may use a separate source! like a database! an XM file! or a scriptto fill the list with selectable items.

)y usin% an imported source! the data is separated from the 4TM! and any chan%es to the itemsare made in the separate data source.

5n the ne&t three chapters! we will describe how to bind data from a scripted data source.

Documents

Data Base Connectivity