1. DATABASES IN VISUAL BASIC.NET
ADO.NET

2. ADO .NET
 ADO.NET is an OO framework that allows
you to interact with DBs
 Can use ADO.NET through code, or by using
bounded controls
 ADO.NET extremely flexible and efficient

3. ADO.NET
 Previously applications would talk to Database
using SQL
 The application would be constantly connected
to the DB
 We still use SQL but the data is disconnected
 It will connect to a database server when it
needs to run a query and then disconnects
immediately
 ADO.NET still provides the connection
oriented traditional approach.

4. Traditional Data Access
Architecture
1. Makes a Connection
2. Pass some query to DB and reads result
3. Pass another query to DB and reads result
4. Disconnects from DB System

5. ADO.NET Disconnected Model
1. Make a connection
2. Pass query and gets back result
3. Disconnects
4. Makes connection again
5. Passes another query and gets result
6. Disconnects from the DB

6. ADO.NET
 Keeps a local virtual copy of the database in
your application
 All of the generic classes for data access are
stored in the System.Data Namespace.

7. ADO.NET
 ADO.NET uses managed providers to
connect to databases
 Managed providers allow fast data streams
from databases
 Deals with security such as database locks,
passwords etc.,

8. Main Components of ADO.NET
Object Description
Connection Creates a connection to the data
source
Command Provides access to commands
that can be executed against the
data source
DataAdapter Serves as an ambassador
between your dataset and
datasource, maps instructions
between the two
DataSet Provides an in-memory
representation of your data source
DataReader Read-Only forward stream
containing your data

9. Advantages
 Interoperability
 Data is transported as XML
 Can be read by anyone on any platform
 Scalability
 Client Server model is gone
 ADO promotes the use of disconnected datasets
 Productivity
 Quicker
 Less Bugs

10. Advantages Cont’d
 Performance
 Disconnected datasets
 Database Server is no longer a bottleneck
 Performance boost
 Concurrency
 Database not locked out all the time

11. Using ADO.NET in Code
1. Set up your objects
2. Connect to DB using connection object
3. Set up the data adapter
4. Copy data from data adapter to Dataset

13. Connecting to a DB in Code
USING ADO.NET WITH ACCESS DB

14. A Simple DB Application

15. Code Cont’d

16. Code Cont’d

17. Code Cont’d

18. Doing it In Code
 An access Database Table
 It will be represented in our DataSet as a Table
 The first table is given an index of 0
 The first row in the table has an index value of 0
also
 The first column has a value of 0

20. Code Cont’d

21. The Code
Set up the objects

23. The Code
Set up the objects

25. The Code
Set up the objects

27. The Code
Set up the objects

29. The Code
Set up the objects

31. The Code
Fill the DataSet using the DataAdapter

32. The Code – Displaying the
DataSet Contents
 Point a textbox to a row and column of the dataset
Table
 Point a DataGrid control at a DataSet
.........................................................................................................
.

33. The Code: Counting the
Number of Rows

34.  Point a textbox to a row and column of the dataset
Table
 Point a DataGrid control at a DataSet
.........................................................................................................
.

35. Customising the Generic
Code

36. Set Up the Objects

37. The Form Load Code

38. The UpdateTextBoxes Sub
Procedure

39. Navigation Code: Previous
Record

40. Navigation Code: Next Record

41. Navigation Code: Find Record