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ADO.NET

ADO.NET

Accessing Databases in VS.NETProfessor Corinne Hoisington

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ADO.NET

ActiveX Data Objects

ADO.NET has a number of classes

that :

Retrieve Data

Manipulate Data

Update Data

VB,C#, C++, J#

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ADO.NET

ADO vs. ADO.NET

ADO works great, but:

Requires COM and Windows

Recordsets dont travel well over the Internet

Connected behavior is hard to work with Requires more code

ADO.NET solves these problems

Uses XML under the covers for all datatransport

No special code needed to marshal acrossthe Internet

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ADO.NET

Disconnected?

ADO.NET offers thecapability of working withdatabases in a disconnectedmanner.

An entire database table canbe retrieved to a localcomputer/temp file if it is anetwork database.

A connection could also beconstant

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ADO.NET

Web-Centric Applications

Download the data andprocess it at a locallevel.

If changes are made, theconnection can beremade and the changesposted.

The database could beLAN or Internet based.

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ADO.NET

Data Providers

MS SQL Server 7.0+

Oracle

OLE DB (old SQL & Access- Jet 4.0)

Open Database Connectivity

(ODBC)- earlier Visual Studio,

Access Driver, ODBC for Oracle

* Version 1.0 does not include ODBC

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ADO.NET

4 Core Classes of ADO.NET

Connection-Connect to database

Command-SQL statement to retrieve

data DataReader-Sequential access to the

data source

DataAdapter-Populate a dataset

& Update the database

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ADO.NET

Other ADO Terms

Fill : The OleDbDataAdapter method Fillretrieves information from the databaseassociated with OleDbConnection and

places this information in the DataSet. DataGrid: A DataGridis the area which

will be filled with data from thedatabase. The DataGrid method

SetDataBinding binds a DataGrid to adata source.

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ADO.NET

Architecture

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ADO.NET

Choices?

Using ADO.NET

we can either

displayinformation in a:

DataGrid

Individual

Controls

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ADO.NET

Lets Connect to a Database

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ADO.NET

Adding a Connection

TheADD CONNECTIONoption is builtinto ADO.NET to create a database

connection in theDATA LINK

PROPERTIESwindow. The DATAADAPTER CONFIGURATION WIZARD isused to set up an OleDbDataAdapterwhich generates queries to theconnected database.

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ADO.NET

Connecting to the Database

Dragging an OleDbDataAdapterfrom the Toolbox to the form ofdisplays the Data AdapterConfiguration Wizard.

Clicking Next on the welcomescreen displays the ChooseYour Data Connection window.

Clicking the New Connectionbutton pops up the Data LinkProperties form. Click theProvider tab, choose MicrosoftJet 4.0 OLE DB Provider

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ADO.NET

SQL Commands:Creating a Query

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ADO.NET

Time to try it!

http://localhost/var/www/apps/conversion/tmp/scratch_4/ADOExample.doc

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ADO.NET

Using a Data Form Wizard

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ADO.NET

Choosing Tables

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ADO.NET

Fill the Form

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ADO.NET

Lets Create Fill in Controls

http://localhost/var/www/apps/conversion/tmp/scratch_4/VB%20Form%20Wizard.doc