Unit4

030010401 BCA 4th Semester
Preeti P Bhatt Department of Computer Science, UTU. 1 | P a g e
030010401- GUI Programming
Unit-4: ADO.NET Programming
BCA 4th Semester
Note: - This material is prepared by Ms. Preeti P Bhatt. The basic
objective of this material is to supplement teaching and discussion
in the classroom. Student is required to go for extra reading in the
subject through library work.

Topic Covered
 ADO.NET architecture and its component
 Connected and disconnected architecture
 Working with the DataSet: creating, filling and modifying DataSet, DataGrid control
 Accessing data: Executing query using Command object, reading data using DataReader
 Executing stored procedure

ADO.NET
ADO.NET is a data access technology from Microsoft .Net Framework , which provides
communication between relational and non-relational systems through a common set of
components.
ADO.NET consists of a set of Objects that expose data access services to the .NET environment.
ADO.NET is built for disconnected architecture, so it enables truly disconnected Data Access
and Data Manipulation through its Dataset Object, which is completely independent from the
Data Source.
ADO.NET provides
• Methods for connecting to data sources
• Retrieving
• Manipulating
• Updating.
ADO.NET Architecture

Two Main Component of ADO.Net
1. Data Provider
The Data Provider is responsible for providing and maintaining the connection to the
database.
Data Provider is a set of ADO.NET classes that allows you to access specific database,
execute SQL command and retrieve the data.
A data provider is a bridge between your application and a data source.
Four Data Providers for ADO.NET
 OLEDB Provider: (Object Linking and Embedding Database)
o Provides access to any data source that has OLEDB driver.(like Access )
o Namespace : OleDb
 Members provide a direct connection to COM(Component Object
Model)-based OLE DB data providers for databases and data
sources other than SQL Server and Oracle.
 ODBC Provider: (Open Database Connectivity)
o Provides access to any data source that has an ODBC driver.
o Namespace : ODBC
 Members provide connectivity to legacy data sources that don’t
have OLE DB data providers.
 SQLServer Provider: provides access to SQL server database
o Namespace : SqlClient
 Members provide high performance connectivity to SQL Server.
 Oracle Provider: provides access to Oracle database.
o Namespace : SqlClient
 Members deliver functionality similar to SqlClient for Oracle
databases.
How to Import Namespace?
Sql Example
Imports System.Data ‘For dataset object
Imports System.Data.SQLClient ‘For data provider object

Object of data provider
The four Objects from the .Net Framework provide the functionality of Data Providers
in ADO.NET.
 Connection Object
 Command
 Data Reader
 Data Adapter
Connection
Connection class allows you to establish a connection to data source.
The connection string is a series of name/value setting separate by semicolon (;)
The few information required in connection string are
 Server where database is located
 Database you want to use
 Database should authenticate you
Connections can be opened in two ways:
 Explicitly by calling the Open method on the connection
 Implicitly when using a DataAdapter.
When creating a connection object you can pass the connection string as a constructor
parameter.
You can also set the ConnectionString property by hand.
Ex: connection with SqlClient
 Without argument constructor
Dim connection as new SqlConnection()
connection.ConnectionString= “Connection String"
 With Argument constructor
Dim connection As SqlConnection
Connection = New SqlConnection ("Connection String")
Common properties and methods
Method/Property Use
Open() open the connection
Close() Close the connection()
ConnectionString The string use to make connection with database

Command
The command class allows you to execute any type of SQL Command.
You can also use command class to perform user defined task such as create table,
alter table etc.
Example:
Dim cnn As SqlConnection
Dim cmd As SqlCommand
cnn = New SqlConnection(“ConnectionString”)
cmd = New SqlCommand("Your SQL Statement Here", cnn)
Property of Command Object
o Connection
o CommandType
o CommandText
o Parameters
Methods for execute commands on the database:
● ExecuteNonQuery: Executes commands that have no return values such as
INSERT, UPDATE or DELETE
● ExecuteScalar: Returns a single value from a database query.
● ExecuteReader: Returns a result set by way of a DataReader object.
Data Reader
DataReader Object in ADO.NET is a stream-based, forward-only, read-only retrieval of
query results from the Data Source, which do not update the data.
The DataReader cannot be created directly from code; they created only by calling the
ExecuteReader method of a Command Object.
Dim cmd As SqlCommand(“Query”, con)
Dim DataReader As new SqlDataReader
DataReader = Command.ExecuteReader()
Common methods of DataReader
o Read() : It is used to read the rows from DataReader and it always moves
forward to a new valid row, if any row exist .
o Close() : it used to close dataReader connection with database.

Data Adapter
DataAdapter is a part of the ADO.NET Data Provider. DataAdapter provides the
communication between the Dataset and the Datasource.
We can use the DataAdapter in combination with the DataSet Object. That is these two
objects combine to enable both data access and data manipulation capabilities.
The DataAdapter can perform Select, Insert, Update and Delete SQL operations in the
Data Source.
The Insert, Update and Delete SQL operations, we are using the continuation of the
Select command perform by the DataAdapter.
That is the DataAdapter uses the Select statements to fill a DataSet and use the other
three SQL commands (Insert, Update, delete) to transmit changes back to the
Database.
Example: Using Command Object
Dim sqlCmd As SqlCommand
Dim adapter As SqlDataAdapter
Dim ds As New DataSet
sqlCmd = New SqlCommand(“Your Select Query”, sqlCnn)
adapter = New SqlDataAdapter(cmd)
adapter.Fill(ds)
Example: Without using Command Object
adapter = New SqlDataAdapter(“Your Select Query”, sqlCnn)
adapter.Fill(ds)
Methods of DataAdapter
 Fill()
 FillSchema()
 Update()

2. DataSet : Second component of ADO.Net
The DataSet is the heart of disconnected data access.
The ADO.NET DataSet contains DataTableCollection and their DataRelationCollection .
It represents a collection of data retrieved from the Data Source. We can use Dataset in
combination with DataAdapter class.
The DataSet object offers disconnected data source architecture. The Dataset can work
with the data it contains, without knowing the source of the data coming from. That is,
the Dataset can work with a disconnected mode from its Data Source.
It gives a better advantage over DataReader , because the DataReader is working only
with the connection oriented Data Sources.
Example
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim connetionString As String
Dim command As SqlCommand
Dim adapter As New SqlDataAdapter
Dim i As Integer
Dim sql As String
connetionString = "Data Source=ServerName;Initial
Catalog=DatabaseName;User ID=UserName;Password=Password"
sql = "Your SQL Statement Here"
connection = New SqlConnection(connetionString)

Try
connection.Open()
command = New SqlCommand(sql, connection)
adapter.SelectCommand = command
adapter.Fill(ds)
adapter.Dispose()
command.Dispose()
connection.Close()
For i = 0 To ds.Tables(0).Rows.Count - 1
MsgBox(ds.Tables(0).Rows(i).Item(0) & " -- " &
ds.Tables(0).Rows(i).Item(1))
Next
Catch ex As Exception
MsgBox("Cannot open connection ! ")
End Try
End Sub
End Class
Connected and Disconnected Architecture
The ADO.NET Framework supports two models of Data Access Architecture,
 Connection Oriented Data Access Architecture
 Disconnected Data Access Architecture.
Connection Oriented Data Access
In Connection Oriented Data Access Architecture the application makes a connection to the
Data Source and then interacts with it through SQL requests using the same connection.
In these cases the application stays connected to the database system even when it is not using
any Database Operations.
Connected Environment (Scenario)
1. Open connection
2. Execute command
3. Process rows in reader
4. Close reader
5. Close connection
Working with data directly via open connection
Advantages Drawbacks
 Simple security realization
 Work with real data
 Simple organization of distributed work
 Continual connection
 Not available via Internet

Disconnection Oriented Data Access
ADO.Net solves connection problem by introduces a new component called Dataset.
The DataSet is the central component in the ADO.NET Disconnected Data Access Architecture.
A DataSet is an in-memory data store that can hold multiple tables at the same time.
Datasets only hold data and do not interact with a Data Source.
Disconnected Environment (Scenario)
1. Open connection
2. Fill the DataSet
3. Close connection
4. Process the DataSet
5. Open connection
6. Update the data source
7. Close connection
Accessing data: Executing query using Command object, reading data
using DataReader
 Executing query using Command object
 Insert
 Update
 Delete
 Select
 Reading data using DataReader
 While select query is used
Example: Executing Query using command Object and DataSet

Imports System.Data.SqlClient
Public Class Form1
Dim con As New SqlConnection("Data Source=.SQLEXPRESS;AttachDbFilename=
D:DotNetProgramming 2013VB.NetProgramDemoSQLConnectivitySQLConnectivity
EMP.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True")
Dim cmd As New SqlCommand()
Dim ad As New SqlDataAdapter()
Dim i As Integer
‘Code For Insert Query
Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnSave.Click
Try
con.Open()
cmd = New SqlCommand("insert into emp_info values
(@id,@name,@desg,@salary)",con)
cmd.Parameters.AddWithValue("@id", Convert.ToInt32(txtId.Text))
cmd.Parameters.AddWithValue("@name", txtName.Text)
cmd.Parameters.AddWithValue("@desg", cbDsgn.SelectedItem)
cmd.Parameters.AddWithValue("@salary", Convert.ToInt32(txtSal.Text))
i = cmd.ExecuteNonQuery()
MsgBox("Data Inserted")
display()
MsgBox(ex.Message)
End Try
con.Close()
End Sub
‘Code For Delete Query
Private Sub btnDelete_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnDelete.Click
Try
con.Open()
cmd = New SqlCommand("delete from emp_info where id=@id", con)
MsgBox("Data deleted")
display()
MsgBox(ex.Message)
End Try
con.Close()
End Sub

Public Sub display()
ds.Clear()
ad = New SqlDataAdapter("select * from emp_info ", con)
ad.Fill(ds, "Temp")
dataGrid.DataSource = ds
dataGrid.DataMember = "Temp"
End Sub
‘Code For Select Query
Private Sub btnSelect_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnSelect.Click
con.Open()
display()
con.Close()
End Sub
‘Code For Update Query
Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnUpdate.Click
Try
con.Open()
cmd = New SqlCommand("update emp_info set name=@name, designation=@desg,
salary=@salary where id=@id", con)
cmd.Parameters.AddWithValue("@name", txtName.Text)
cmd.Parameters.AddWithValue("@desg", cbDsgn.SelectedItem)
cmd.Parameters.AddWithValue("@salary", Convert.ToInt32(txtSal.Text))
MsgBox("Data Updated")
display()
MsgBox(ex.Message)
End Try
con.Close()
End Sub
‘Code For cell selection in gridview
Private Sub dataGrid_CellClick(ByVal sender As System.Object, ByVal e As
System.Windows.Forms.DataGridViewCellEventArgs) Handles dataGrid.CellClick
Dim r As Integer
r = dataGrid.CurrentCell.RowIndex
txtId.Text = dataGrid.Rows(r).Cells(0).Value
txtName.Text = dataGrid.Rows(r).Cells(1).Value
cbDsgn.SelectedItem = dataGrid.Rows(r).Cells(2).Value
txtSal.Text = dataGrid.Rows(r).Cells(3).Value
End Sub

‘Code For Select Query
Sub Navigate()
Dim r As Integer
r = Me.BindingContext(ds, "Temp").Position
txtId.Text = dataGrid.Rows(r).Cells(0).Value
txtName.Text = dataGrid.Rows(r).Cells(1).Value
cbDsgn.SelectedItem = dataGrid.Rows(r).Cells(2).Value
txtSal.Text = dataGrid.Rows(r).Cells(3).Value
End Sub
Private Sub btnCurrent_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnCurrent.Click
Navigate()
End Sub
Private Sub btnLast_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnLast.Click
Me.BindingContext(ds, "Temp").Position = Me.BindingContext(ds,
"Temp").Count - 1
Navigate()
End Sub
Private Sub btnNext_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnNext.Click
"Temp").Position + 1
Navigate()
End Sub
Private Sub btnPrevious_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnPrevious.Click
"Temp").Position - 1
Navigate()
End Sub
Private Sub btnFirst_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btnFirst.Click
Me.BindingContext(ds, "Temp").Position = 0
Navigate()
End Sub
End Class

Example: Reading data using DataReader
DataGrid Control
The DataGridView can display data in
 Bound mode – Static Binding- Directly from Gridview
 Bound mode is suitable for managing data using automatic interaction with the
data store.
 One very common use of the DataGridView control is binding to a table in a
database.
 Unbound mode – Dynamic Binding (Using Code)
 Unbound mode is suitable for displaying relatively small amounts of data that
you manage programmatically.
To bind GridView we can use two properties
 DataSource— It gets or sets DataSource that the DataGridView is displaying data.
 The data source, typically a dataset
 DataMember— It get or set the name of the table in the DataSource for which the
DataGridView is display data.
Example:
DataGridView1.DataSource = dataset Object
DataGridView1.DataMember = “Student"
Dim con As New SqlConnection("Data Source=.SQLEXPRESS;AttachDbFilename=D:
DotNetProgramming 2013VB.NetProgram
DemoSQLConnectivitySQLConnectivityEMP.mdf;
Integrated Security=True;Connect Timeout=30;User
Instance=True")
Dim cmd As New SqlCommand()
Dim dr As SqlDataReader
cmd = New SqlCommand("select * from emp_info ", con)
dr = cmd.ExecuteReader()
While dr.Read()
MsgBox(dr(0) & " , " & dr(1) & " , " & dr(2) & " , " & dr(3))
End While
dr.Close()
con.Close()

Working with the Dataset:
 Dataset is a disconnected, in-memory representation of the data.
 It can be consider as local copy of portion of database.
 It can be manipulated and updated independent of the database.
 Creating, filling and modifying DataSet
o Create object of dataset
o Create DataTable object
o Create DataColumn object
o Add Column in DataTable
o Create DataTable row
o Assign value in each column
o Add DataTable in DataSet
Example
Dim idCoulumn As DataColumn
Dim nameCoulumn As DataColumn
dt = New DataTable()
dt.TableName = "Data"
idCoulumn = New DataColumn("ID", Type.GetType("System.Int32"))
nameCoulumn = New DataColumn("Name", Type.GetType("System.String"))
dt.Columns.Add(idCoulumn)
dt.Columns.Add(nameCoulumn)
dr = dt.NewRow()
dr("ID") = 1
dr("Name") = "Name1"
dt.Rows.Add(dr)
dr = dt.NewRow()
dr("ID") = 2
dr("Name") = "Name2"
dt.Rows.Add(dr)
ds.Tables.Add(dt)
End Sub

Executing stored procedure
The data provider is a set of components that include the Connection, Command, DataReader,
and DataAdapter Objects.
The command Object provides a number of Execute methods that can be used to perform the
SQL queries in a variety of fashions.
A stored procedure is a precompiled executable object that contains one or more SQL
statements. A sample Stored Procedure is given below:
CREATE PROCEDURE Procedure_name
AS
Procedure Command
GO
Example
CREATE PROCEDURE SPPUBLISHER
AS
SELECT PUB_NAME FROM publishers
GO
The above code creates a procedure named as 'SPPUBLISHER' and it execute SQL statement
that selects all publisher names from publishers table from the PUB database.
Using stored procedures, database operations can be encapsulated in a single command,
optimized for best performance, and enhanced with additional security.
To call a stored procedure from VB.NET application, set the CommandType of the Command
object to StoredProcedure.
Command.CommandText=”StoreProcedure Name”
command.CommandType = CommandType.StoredProcedure

From the following source code you can see how to call a stored procedure from VB.NET
application.
Imports System.Data.SqlClient
Public Class Form1
Dim connetionString As String
Dim command As New SqlCommand
Dim i As Integer
connetionString = "Data Source=servername;Initial
Catalog=PUBS;User ID=sa;Password=yourpassword"
connection = New SqlConnection(connetionString)
connection.Open()
command.Connection = connection
command.CommandType = CommandType.StoredProcedure
command.CommandText = "SPPUBLISHER"
adapter = New SqlDataAdapter(command)
adapter.Fill(ds)
For i = 0 To ds.Tables(0).Rows.Count - 1
MsgBox(ds.Tables(0).Rows(i).Item(0))
Next
connection.Close()
End Sub
End Class

Unit4

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