The document discusses ADO.NET and how it provides disconnected data access through the use of datasets, data adapters, and data providers. It covers the core ADO.NET objects like connection, command, data reader, and data adapter. It provides examples of loading data from databases into datasets using data adapters and binding datasets to controls for display and editing. The .NET framework supports multiple data providers for different database systems like SQL Server, Oracle, OLE DB, and ODBC.

1. ADO.NET
database connection
@wong
Ref:: http://www.anekwong.com

2. ADO.NET
• ADO.NET
.NET
• ADO => ActiveX Data Object
.NET

3. ADO NET Architecture
• NET Framework data providers
• The DataSet

4. windows Data Sources
Windows Data sources
(data source)
-
-
IDE
,
(bind)

5. Data Provider
•
Query
•
Object
DataSet
•
VS2005
–
–
–
–
SQL Server Data Provider
OLEDB Data Provider
Oracle Data Provider
ODBC Data Provider
MS SQL Server
MS Access
V.7

6. Data Provider
• Data Provider
– Connection
– Command
Query
SQL
– DataAdapter
fill
DataSet
– DataReader
result set
read-only
forward-only /

7. NET Framework Data Providers
NET Framework
data provider
Description
NET Framework Data Provider for SQL Server
Provides data access for Microsoft SQL
Server version 7.0 or later Uses the
System.Data.SqlClient namespace
NET Framework Data Provider for OLE DB
For data sources exposed using OLE DB
Uses the System.Data.OleDb namespace
NET Framework Data Provider for ODBC
For data sources exposed using ODBC Uses
the System.Data.Odbc namespace
NET Framework Data Provider for Oracle
For Oracle data sources The NET Framework
Data Provider for Oracle supports Oracle
client software version 8.1.7 and later, and
uses the System.Data.OracleClient
namespace

8. Core Objects of NET Framework Data Providers
Object Description
Connection
Establishes a connection to a specific data source The base
class for all Connection objects is the DbConnection class
Command
Executes a command against a data source Exposes
Parameters and can execute within the scope of a
Transaction from a Connection. The base class for all
Command objects is the DbCommand class
DataReader
Reads a forward-only, read-only stream of data from a data
source The base class for all DataReader objects is the
DbDataReader class
DataAdapter
Populates a DataSet and resolves updates with the data
source The base class for all DataAdapter objects is the
DbDataAdapter class

9. - The NET Framework Data Provider for SQL Server
Imports Provider
Imports System Data SqlClient
- The .NET Framework Data Provider for OLE DB
Imports Provider
Imports System Data OleDb
Driver
Provider
SQLOLEDB
Microsoft OLE DB Provider for SQL Server
MSDAORA
Microsoft OLE DB Provider for Oracle
Microsoft Jet OLEDB 4.0
OLE DB Provider for Microsoft Jet

10. - The NET Framework Data Provider for ODBC
Imports Provider
Imports System Data Odbc
Driver
SQL Server
Microsoft ODBC for Oracle
Microsoft Access Driver
mdb
- The NET Framework Data Provider for Oracle
Imports Provider
Imports System.Data
Imports System.Data.OracleClient

11. Choosing a NET Framework Data Provider
Provider
Notes
NET Framework
Data Provider
for SQL Server
Recommended for middle-tier applications using Microsoft SQL Server
7.0 or later
Recommended for single-tier applications using Microsoft Database
Engine MSDE or SQL Server 7.0 or later
Recommended over use of the OLE DB Provider for SQL Server
SQLOLEDB with the NET Framework Data Provider for OLE DB
For SQL Server 6.5 and earlier, you must use the OLE DB Provider for
SQL Server with the NET Framework Data Provider for OLE DB
NET Framework
Data Provider
for OLE DB
Recommended for middle-tier applications using SQL Server 6.5 or
earlier
For SQL Server 7.0 or later, the NET Framework Data Provider for SQL
Server is recommended
Also recommended for single-tier applications using Microsoft Access
databases Use of an Access database for a middle-tier application is
not recommended
NET Framework
Data Provider
for ODBC
Recommended for middle and single-tier applications using ODBC data
sources
NET Framework
Data Provider
for Oracle
Recommended for middle and single-tier applications using Oracle data
sources

12. 2. Data Set Designer
Vs
DataSet
.Net Framework
disconnected data access
(
Data Table)
)
DataSet (
DataSet

13. ADO NET DataSet

14. dataSet
Data Table
Customers
Orders
Table Adapter
SME
Table Adapter
Customer
Orders

15. DataSet
•
DataSet
Disconnected data access
•
– DataTable

16. dataSet
TableAdapter
TableAdapter
DataSet
DataSet
Tableadapter.Fill(datatable)
Tableadapter
Datatable
DataSet
DataTable TableAdapter
Data Table

17. Dataset.table(row).field
Dataset
Table
Row
count-1
Field
Dataset
count

18. Tableadapter.Fill(datatable)
Fill
GetData
GetData
DataTable
TableAdap
D
GetData

19. Data Binding
Data Binding
(bind)
DataBinding
code
Dat
Dat

20. ADO NET Sample Application
Option Explicit On
Option Strict On
Provider
SqlClient
Imports System
Imports System Data
Imports System Data SqlClient
Public Class Program
Public Shared Sub Main
Dim connectionString As String GetConnectionString
Dim queryString As String _
SELECT CategoryID, CategoryName FROM dbo Categories;
Using connection As New SqlConnection connectionString
Dim command As SqlCommand connection CreateCommand
command CommandText queryString

21. Try
connection Open
Dim dataReader As SqlDataReader _
command ExecuteReader
Do While dataReader Read
Console WriteLine vbTab & {0} & vbTab & {1} , _
dataReader 0 , dataReader 1
Loop
dataReader Close
Catch ex As Exception
Console WriteLine ex Message
End Try
End Using
End Sub
Private Shared Function GetConnectionString As String
' To avoid storing the connection string in your code,
' you can retrieve it from a configuration file
Return Data Source local ;Initial Catalog Northwind; _
& Integrated Security SSPI;
End Function
End Class

22. ADO NET Sample Application
Option Explicit On
Option Strict On
Provider
Imports System
Imports System Data
Imports System Data OleDb
Public Class Program
Public Shared Sub Main
Dim connectionString As String GetConnectionString
Dim queryString As String _
SELECT CategoryID, CategoryName FROM Categories;
Using connection As New OleDbConnection connectionString
Dim command As OleDbCommand connection CreateCommand
command CommandText queryString
Try
OleDb

23. Try
connection Open
Dim dataReader As OleDbDataReader _
command ExecuteReader
Do While dataReader Read
Console WriteLine vbTab & {0} & vbTab & {1} , _
dataReader 0 , dataReader 1
Loop
dataReader Close
Catch ex As Exception
Console WriteLine ex Message
End Try
End Using
End Sub
Private Shared Function GetConnectionString As String
' To avoid storing the connection string in your code,
' you can retrieve it from a configuration file
' Assumes Northwind mdb is located in c Data folder
Return Provider Microsoft Jet OLEDB 4.0;Data Source _
& c DataNorthwind mdb;User Id admin;Password ;

24. Just do it!
•
•
OleDB Provider
Northwind
Ms Access
Import
Provider
Imports System.Data.OleDB
Dim objConn As New System.Data.OleDbConnection()
objConn.ConnectionString = “Provider=Microsoft.Jet.OLEDB.4.0;
Data Source=C:Northwind.mdb”

25. objConn.Open()
objConn.Close()

26. Command
Sql
Select, Update, Delete, Insert
Dim objComm As New OleDb.OleDbCommand()
Provider
CommandText
objComm.CommandText = “Select * from Employyes”
objComm.ExecuteNonQury
objComm.ExecuteScalar
objComm.ExecuteReader

27. Command
Sql
Select, Update, Delete, Insert
Dim objComm As New OleDb.OleDbCommand()
Provider
CommandText
objComm.CommandText = “Select * from Employyes”
objComm.ExecuteNonQury
objComm.ExecuteScalar
objComm.ExecuteReader

28. objComm.ExecuteReader
Set
dataReader
Dim dr As OleDb.OleDbDataReader
dr = objComm.ExcuteReader
Item
DataReader
While dr.read()
Dim myObj As object = dr.Item(3)
Dim myOtherObj As object = dr.Item(“Customer”)
End While

29. objComm.ExecuteReader
Set
dataReader
Dim dr As OleDb.OleDbDataReader
dr = objComm.ExcuteReader
Item
DataReader
While dr.read()
Dim myObj As object = dr.Item(3)
Dim myOtherObj As object = dr.Item(“Customer”)
End While

30. DataReader
Click
ListBox1

31. Dim strSQL As String = “Select CustomerID,CompanyName F
Sub
Dim objConn As New OleDbConnection(StrConn)
Dim objComm As New OleDbCommand(strSQL,objConn)
Dim dr As OleDbDataReader
objConn.Open()
dr = objComm.ExecuteReader()
ListBox1.Items.Add(“
” & ControlChars.Tab & “
Do while dr.Read()
Dim strRecord As String = dr.Item(“CustomerID”).tostring(
Item(“CompanyName”).Tostring()
ListBox1.Items.Add(strRecord)
Loop

32. DataReader

33. DataAdapter
DataAdapter => Dim da As New OleDb.OleDbDataAdapter
Method Fill
DataSet => dataAdapter.Fill(dataSet,tab
Dim objConn As New Data.OleDbConnection(“Provider=Microsoft.Jet.OL _
EDB.4.0;Data Source=C:Northwind.mdb”)
Dim strSQL As String = “Select * from Employees”
Dim da As New OleDb.OleDbDataAdapter
Da.SelectCommand = New OleDb.OleDbCommand(strSQL,objConn)
Dim ds As New DataSet
da.Fill(ds,”Employees”)
dataSet
dataSet.Tables(table).rows(row).(field)
textbox1.text = ds.Tables(“employees”).row(0).(“FirstName”)
ds.Tables(“employees”).row(0).(“FirstName”

34. DataAdapter
Method Update
=> dataAdapter.Update(dataSet,table)

35. DataSet
•
DataSet
Dim tb As DataTable = ds.Tables(“Employees”)
Dim row As DataRow = tb.NewRow()
row(“FirstName”) = “Chaimard”
row(“LastName”) = “Kama”
tb.Rows.Add(row)

36. 
DataSet
Dim tb As DataTable = ds.Tables(“Employees”)
For Each row As DataRow In tb.Rows
if row(“FirstName”) = “Chaimard” Then
row.(“FirstName”) = “Superman”
end if
Next

37. 
DataSet
Dim tb As DataTable = ds.Tables(“Employees”)
For Each row As DataRow In tb.Rows
if row(“FirstName”) = “Chaimard” Then
row.dalete()
end if
Next

38. Binding
Data
• Simple Binding Data
textbox, Label
• Complex Binding Data
ListBox, ComboBox

39. 
Simple Binding Data
:
object.DataBindings.Add(propertyName,dataSource,dataMember)
: textbox1.dataBindings.Add(“text”,ds.Tables(“emp”), “FirstName”)

Listbox1.DataSource = ds.Tables(“emp”)
Listbox1.DisplayMember = “FirstName”
:
Complex Binding Data
With cboStudent
ComboBox
.datasource = ds.Tables(“Faculty”)
.displaymember = “DescriptionThai”
.ValueMember = “FacultyCode”
.DataBindings.Add(“SelectValue”,objBS,“facultyCode”)
End with
2.
Student
Student

40. 
: me.bindingContext(ds.Tables.(“emp”)).position = 0
: me.bindingContext(ds.Tables.(“emp”)).position +=
1
: me.bindingContext(ds.Tables.(“emp”)).position =1
:
me.bindingContext(ds.Tables.(“emp”)).position =
me.bindingContext(ds.Tables.(“emp”)).count - 1

BindingSource
Dim objBS As New BindingSource
objBS.DataSource =
ds.Tables(“emp”)
(ds.Tables(“emp”)
emp )
: objBS.MoveFirst
: objBS.MoveNext