VB .net tutorial - 5

8/14/2019 VB .net tutorial - 5

1/30

Working with ADO.NET

NIIT Working with ADO.NET/Lesson 5/Slide 1 of 30

Objectives

In this lesson, you will learn to:

Identify the need for ADO.NET

Identify the features of ADO.NET

Identify the components of the ADO.NET object model

Connect to a database by creating a data adapter

Access a database through a dataset

Preview the data adapter result


2/30



ADO.NET

Is a model used by Visual Basic .NET applications to

communicate with a database for retrieving, accessing, and

updating data.

Uses a structured process flow to interact with a database.


3/30



Features of ADO.NET

Disconnected data architecture Applications connect to

the database only while retrieving and updating data.

Data cached in datasets ADO.NET is based on adisconnected data structure. Therefore, the data is retrieved

and stored in datasets.

Data transfer in XML format ADO.NET uses XML for

transferring information from a database into a dataset andfrom the dataset to another component.

Interaction with the database is done through data

commands.


4/30



Just a Minute

List the features of ADO.NET.


5/30



ADO.NET Object Model

DATASET

VISUAL BASIC

.NET

APPLICATION

(WINDOWS/

WEB FORM)

DATA PROVIDER

Accessing

retrieved data

Accessing retrieved

data

CONNECTION

COMMAND

DATA ADAPTER

DATA READER

Establishesconnection with

the database

Filling datasetwithdata

Transfers data to

the dataset and

reflects the

changes made in

the dataset to the

database

DATABASE

Retrieves data in a

read-only,

forward only mode

Executes a

command to retrieve

data from thedatabase


6/30



ADO.NET Object Model (Contd.)

Data from a database can be assessed through:

A dataset

A DataReader object


7/30



Key Components of the ADO.NET Model

Data Provider

Is used for connecting to a database, retrieving data,

and storing the data.

Is of two types:

OLE DB data provider

SQL Server data provider


8/30



Just a Minute

Identify the two types of data providers and list the difference

between them.


9/30



Components of a Data Provider

Connection

Used to establish a connection with a data source

Some commonly used properties and methods:

ConnectionString property

Open()method

Close()method

State property


10/30



Components of a Data Provider (Contd.)

Data adapter

Creates a dataset and updates the database.

Handles data transfer between the database and the

dataset through its properties and methods.

Displays the data through the process of table mapping.

Are of two types:

SqlDataAdapter

OleDbDataAdapter


11/30



Just a Minute

What is the function of a data adapter?


12/30




Data command

Is a SQL statement or a stored procedure that is used to

retrieve, insert, delete, or modify data from a datasource.

Is an object of the OleDbCommand orSQLCommand

class.


13/30




Data reader

Is used to retrieve data from a data source in a

read-only and forward-only mode.

Stores a single row at a time in the memory.

Commonly used methods:

Read()

Close()

NextResult()


14/30



Dataset

Is a disconnected, cached set of records that are retrieved

from a database.

Is present as a DataSet class in the System.Datanamespace.

Has its own object model.


15/30



Dataset Object Model

DataRow DataColumn

DATASET

DataRelationCollection

DataRelation

DataTableCollection

DataTable

DataRowCollection DataColumnCollection

ExtendedProperties

DataVi ew PrimaryKe y


16/30



Just a Minute

What are the various components of a dataset?


17/30



Problem Statement 5.D.1

The call center application needs to provide the facility of

viewing the customer details for the Sales department.


18/30



Task List

Identify the data that needs to be displayed.

Identify the method for creating a data adapter.

Identify the type of dataset to be created.

Create a data adapter.

Create a dataset.

Preview the database records.


19/30



Task 1: Identify the data that needs to be displayed.

Result:

As per the given problem statement, the data to be

displayed is as follows:

CustID

FName

LName

Address

Phone

email


20/30



Task 2: Identify the method for creating a dataadapter.

There are three methods to create a data adapter:

Manually

Through a wizard

Using the Server Explorer window

Result:

In the given problem statement, you will create a data

adapter by using Data Adapter Configuration Wizard since it

lets you create a data adapter with minimum steps.


21/30



Just a Minute

What are the different methods of creating a data adapter?


22/30



Task 3: Identify the type of dataset to be created.

Datasets are of two types:

Typed

Untyped

Typed dataset

Is derived from the DataSet class and has an

associated XML schema, which is created at the time ofthe creation of the dataset.

Can be customized after creation.

Supports Intellisense and auto completion for theelements of the syntax while writing code.


23/30



Task 3: Identify the type of dataset to be created.(Contd.)

Untyped dataset

Does not have any associated XML schema, therefore,the structure of an untyped dataset is not known at thecompile time.

Represents tables and columns as collections.

Does not support Intellisense and auto completion forthe elements of the syntax.

Result:

Since the structure of the data is known at compile time,

you will create a typed dataset for the given problemstatement.


24/30



Just a Minute

What is the difference between typed and untyped dataset?


25/30



Task 4: Create a data adapter.

Task 5: Create a dataset.

Task 6: Preview the database records.


26/30



Problem Statement 5.P.1

An application needs to be created that allows the Diaz

Telecommunications Sales Manager to preview the customer

order details from the database. In addition, for each order,

percentage of the cost of a product given as advance needs tobe previewed.


27/30



Summary

In this lesson, you learned that:

ADO.NET is a data access programming model for

accessing the data stored in a database from a .NETapplication.

ADO.NET has the following features:

A disconnected data architecture

Data cached in datasets

The use of XML format for data transfer

Database operations done through data commands


28/30



Summary (Contd.)

ADO.NET consists of the following components:

Data Provider Used for connecting to a database,

retrieving data, storing the data in a dataset, andupdating the database.

Data Adapter A data adapter is integral to the

working of the ADO.NET model since data transfer to

and from the database is done through a data adapter.

Dataset A dataset is a disconnected cached set of

records that are retrieved from the database.

A data adapter communicates with a database through datacommands. These data commands use parameters for

execution.


29/30



Summary (Contd.)

After a dataset has been created, a data adapter uses the

process of table mapping to map the columns in the

database table with the dataset columns.

A data adapter can be created by using any of the following

methods:

Manually

Through a wizard

By using Server Explorer


30/30



Summary (Contd.)

Datasets are of two types:

Typed datasets A typed dataset is derived from the

DataSet class and has an associated schema. Untyped datasets An untyped dataset does not have

any associated XML schema. The tables and columns

in an untyped dataset are represented as collections.

VB .net tutorial - 5

Documents

Transcript of VB .net tutorial - 5