ADO.NETADO.NET

By K.Yesu Ratnam

What is ADO.NETWhat is ADO.NETADO.NET is not a different

technology, in simple terms you can think of a set of classes that can be used to interact with data sources like databases and xml files

This data can, then be consumed in any .net application.

ADO.net stands for Microsoft ActiveX Data Objects.

The following are , a few of the different types of .net applications that use ADO.NET to connect to a database,execute commands and retrieve data.

Asp.net Web applications Console Applications Window Applications

Dot Net Data ProvidersDot Net Data ProvidersSqlServer System.Data.SqlClient

Oracle System.Data.Oracle

Odbc System.Data.Odbc

Oledb System.Data.Oledb

ADO.NETADO.NETCONNECTION ORIENTED MODELDISCONNECTED ORIENTED

MODEL

CONNECTION ORIENTED CONNECTION ORIENTED MODELMODELWhenever an application uses

the connection oriented model to interact with the db then the connectivity between the application and the database has to be maintained always.

Connection OrientedConnection Oriented

Whenever an user executes any statement other than a select then command object can be binded directly to the application

If the user executes a select statement then dataReader is used to bind the result to the application

Application db

ConnectionCommandData Reader

DATA PROVIDERS

Disconnected Oriented Disconnected Oriented Model in ADO.netModel in ADO.netWhen the user interacting with the db using

this model then while performing the manipulations or navigations on the data connectivity between the application and the database is not required

Note: When ever the data is been updated on to the database then the connectivity is required in the disconnected model.

DISCONNECTED MODELDISCONNECTED MODEL

DatabaseDataSetApplication

Data Adapter Connection

Data View

Data Providers

This is available in client system

ADO.NET

DISCONNECTED MODEL CONNECTION ORIENTED MODEL

CONNECTION

DATA ADAPTER

DATA SET

DATA VIEW

UI

CONNECTION

COMMAND

DATA READER

UI

Used if the data has to be filtered,sorted or if the data has to be projected in page-wise

Used if the statement is select statement

ADO.NET OBJECTSADO.NET OBJECTSConnectionCommandDataReaderDataSetDataAdapter

Connection ObjectConnection ObjectTo interact with a database.Syntax:xxConnection con=new

xxConnection(“providerinfo”);Example(creating connection with Oledb):OledbConnection con=new

OledbConnection(“Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:/Documents and Settings/Meghana/Desktop/KRISHNA.mdb“);

Command ObjectCommand ObjectSend sql statements to the data

baseSyntax:

xxCommand cmd=new xxCommand(“sql stmt”);

Example: OleDbCommand cmd1 = new

OleDbCommand("select * from student", con);

DataReader ObjectDataReader ObjectIts allows you to obtain the

results of a select statement from a Command object.

For performance reasons, the data returned from a data reader is a fast forward only stream of data.

DataSet ObjectDataSet ObjectDataset objects are in-memory

representation of data. They contain multiple data table objects.

Which contain columns and rows,just like normal data base tables.

Cont..Cont..One of the most common way to

use a dataset is to load it from a relational database when the program starts, use various controls to display the data and let the user manipulate it interactively and the save the changes back to database when the program ends.

Data Adapter ObjectData Adapter ObjectThe data adapter makes it easy

to you to accomplish these things by helping to manage data in a disconnected mode.

The data adapter fills a DataSet object when reading the data and writes in a single batch when persistence changes back to the data base.

Connect to Data Base using Connect to Data Base using Oledb Data ProviderOledb Data ProviderSteps to Connect to the database 1.Using System.Data.Oledb 2.Establish the connection using

OledbConnection(“parameters”) 3.OledbCommand(“sqlstmt”); 4.Execute query

These four steps are mandatory to establish and insert the data into database.

Insert Data Into DatabaseInsert Data Into Database1.OleDbConnection con = new

OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:/Documents and Settings/Meghana/Desktop/KRISHNA.mdb");

2. con.Open(); 3. OleDbCommand cmd=new OleDbCommand("insert into student

values('"+TextBox1 .Text+"','"+TextBox2 .Text+"','"+TextBox3.Text+"','"+TextBox4 .Text+"','"+TextBox5 .Text+"')",con);

4. cmd.ExecuteNonQuery();

Retrieve Data From Retrieve Data From DatabaseDatabaseOleDbCommand cmd1 = new

OleDbCommand("select * from student", con);

OleDbDataReader or = cmd1.ExecuteReader();

GridView1.DataSource = or; GridView1.DataBind();

Design the pageDesign the pageWith following fields First Name Last Name Qualification Mobile Location

Source CodeSource Code OleDbConnection con = new

OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:/Documents and Settings/Meghana/Desktop/KRISHNA.mdb");

con.Open(); OleDbCommand cmd = new OleDbCommand("insert into

student values('" + TextBox1.Text + "','" + TextBox2.Text + "','" + TextBox5.Text + "','" + TextBox3.Text + "','" + TextBox4.Text + "')", con);

cmd.ExecuteNonQuery(); TextBox1.Text = ""; TextBox2.Text = ""; TextBox3.Text = ""; TextBox4.Text = ""; TextBox5.Text = ""; con.Close(); Label5 .Text=" The data is stored successfully";

ADO.NET

SQL-SERVER ORACLE OleDB Providers ODBC providers

SQL Connection

SQL Command

SQL Datareader

SQL DataAdapter

Oracle Connection

Oracle Command

Oracle DataReader

Oracle DataAdapter

OleDB Connection

OleDB Command

OleDB Data Provider

OleDB DataAdapter

ODBC Connection

ODBC Command

ODBC DataProvider

ODBC DataAdapter

System.data.SqlClient

System.data.OracleClient

System.data.Oledb

System.data.ODBC

Syntax to define the Object◦ Dim objectName as new xxxConnection(“ProviderInfo”)

where xx can be either SQL,Oracle,Oledb or ODBC Provider Info

◦ To connect to MS-Access 2000 above versions Provider=microsoft.jet.oledb.4;datasource=databaseName.mdb

◦ To connect to SQL-Server db Provider=sqloledb.1;userid=sa;password=;database=database

name;datasource=servername Note if SQL Connection is used then provider=providername is

not required.◦ To Connect to ORACLE

Provider = oracleoledb.oracle;userid=scott;pwd=tiger;datasource = servername

OR Provider = msdaora.1;……. Note if oracle connection is used then provider= provider name

is not required.

To define Command Object ◦ Dim objectName as new xxxCommand([SQL

Statement,connection object/Connection String]) To define DataReader

◦ Dim objectName as xxxDataReader To define DataAdapter

◦ Dim objectName as xxxDataAdapter(Select Statement,<Connection Object / Connection String>)

◦ When ever the DataAdapter is defined using the above syntax then only the command relevant for the SelectCommand will be defined and in order to use the above commands they have to be build explicitly.

To define DataSet ◦ Dim objectName as new DataSet()

To define DataView ◦ Dim objectName as new

DataView(datasetName.DataMemberName)

Working with query to retrieve Working with query to retrieve resultresult

using System.Data.SqlClient;public partial class login : System.Web.UI.Page{ SqlConnection conn = new SqlConnection("data source=.;initial catalog=nutan;integrated security=sspi"); SqlCommand cmd; SqlDataReader dr; protected void Page_Load(object sender, EventArgs e) { conn.Open(); Response.Write("connected"); } protected void Button1_Click(object sender, EventArgs e) { cmd = new SqlCommand("select * from mylogin", conn); dr = cmd.ExecuteReader(); while (dr.Read()) { if (dr.GetValue(0).ToString() == TextBox1.Text && dr.GetValue(1).ToString() == TextBox2.Text) { Response.Redirect("Home.aspx"); break; }

} }}

All operationsAll operations

private void button2_Click(object sender, EventArgs e) { OleDbCommand cmd = new OleDbCommand("update emp set salary='"+textBox4 .Text+"',location='"+textBox5 .Text +"' where empid='"+textBox1 .Text +"' ", con); con.Open(); button1.Enabled = true; button4.Enabled = true; textBox1.Enabled = true; textBox1.Text = ""; textBox2.Enabled = true; textBox2.Text = ""; textBox3.Text = ""; textBox3.Enabled = true; textBox4.Text = ""; textBox5.Text = ""; int x=cmd.ExecuteNonQuery(); if(x>0) MessageBox.Show("Yes your data is updated"); else MessageBox.Show("Sorry No Records");

con.Close();

}

private void button1_Click(object sender, EventArgs e) { con.Open(); OleDbCommand cmd = new OleDbCommand("insert into emp

values('" + textBox1.Text + "','" + textBox2.Text + "','" + textBox3.Text + "','" + textBox4.Text + "','" + textBox4.Text + "')", con);

cmd.ExecuteNonQuery(); con.Close(); MessageBox.Show("Data Inserted Success fully"); textBox1.Text = ""; textBox2.Text = ""; textBox3.Text = ""; textBox4.Text = ""; textBox5.Text = "";

}

private void button3_Click(object sender, EventArgs e) { button1.Enabled = false; button4.Enabled = false; OleDbCommand cmd = new OleDbCommand("select * from emp where

empid='"+textBox1 .Text +"'", con); con.Open(); OleDbDataReader dr=cmd.ExecuteReader(); while (dr.Read()) { textBox2.Text = dr.GetValue(1).ToString(); textBox3.Text = dr.GetValue(2).ToString(); textBox4.Text = dr.GetValue(3).ToString(); textBox5.Text = dr.GetValue(4).ToString(); textBox1.Enabled = false; textBox2.Enabled = false; textBox3.Enabled = false; button2.Enabled = true;

} con.Close(); }

private void button4_Click(object sender, EventArgs e) { con.Open(); OleDbCommand cmd = new OleDbCommand("delete from emp

where empid='" + textBox1.Text + "'", con); cmd.ExecuteNonQuery(); MessageBox.Show("The record is Deleted"); textBox1.Text = ""; con.Close();

}