Using ADO.NET Chapter Microsoft Visual Basic.NET: Reloaded 1

2 Objectives Define the terms used when talking about databases Explain the purpose of the DataAdapter, Connection, and DataSet objects Explain the role of the provider Create and configure an OleDbDataAdapter object Write SQL SELECT statements

3 Microsoft Visual Basic.NET: Reloaded Objectives ( continued ) Create a dataset Display a dataset in various controls in an interface Position the record pointer in a dataset

4 Microsoft Visual Basic.NET: Reloaded Database Terminology Database Organized collection of related information stored in a file on a disk Relational database stores information in tables composed of columns and rows Table is a group of related records Each row represents a record Each column represents a row Primary key is a field that uniquely identities a record in a table Foreign key is a field in one table used as the primary key in another table Tables are related by a common field or fields

5 Microsoft Visual Basic.NET: Reloaded Database Terminology ( continued )

6 Microsoft Visual Basic.NET: Reloaded Database Terminology ( continued )

7 Microsoft Visual Basic.NET: Reloaded ADO.NET A Connection object is used to establish a temporary connection to a database Requests for information are then submitted using a DataAdapter object The DataAdapter uses a provider which translates the request into a language the database understands A DataSet stores a copy of the records and fields requested in a internal memory location

8 Microsoft Visual Basic.NET: Reloaded ADO.NET ( continued )

9 Microsoft Visual Basic.NET: Reloaded ADO.NET ( continued )

10 Microsoft Visual Basic.NET: Reloaded Creating and Configuring a DataAdapter Object

11 Microsoft Visual Basic.NET: Reloaded Creating and Configuring a DataAdapter Object ( continued )

12 Microsoft Visual Basic.NET: Reloaded Creating and Configuring a DataAdapter Object ( continued )

13 Microsoft Visual Basic.NET: Reloaded Creating and Configuring a DataAdapter Object ( continued )

14 Microsoft Visual Basic.NET: Reloaded Creating and Configuring a DataAdapter Object ( continued )

15 Microsoft Visual Basic.NET: Reloaded Creating and Configuring a DataAdapter Object ( continued )

16 Microsoft Visual Basic.NET: Reloaded SQL Structured Query Language (SQL) A set of commands that allows you to access and manipulate the data stored in many database management systems on computers of all sizes SELECT statement allow you to specify which fields and records you want to view WHERE clause limits records to be selected ORDER BY clause sorts record display order

17 Microsoft Visual Basic.NET: Reloaded HOW TO…

18 Microsoft Visual Basic.NET: Reloaded HOW TO… ( continued )

19 Microsoft Visual Basic.NET: Reloaded Using the Query Builder to Enter a SELECT Statement

20 Microsoft Visual Basic.NET: Reloaded Using the Query Builder to Enter a SELECT Statement ( continued )

21 Microsoft Visual Basic.NET: Reloaded Using the Query Builder to Enter a SELECT Statement ( continued )

22 Microsoft Visual Basic.NET: Reloaded Using the Query Builder to Enter a SELECT Statement ( continued )

23 Microsoft Visual Basic.NET: Reloaded Using the Query Builder to Enter a SELECT Statement ( continued )

24 Microsoft Visual Basic.NET: Reloaded Using the Query Builder to Enter a SELECT Statement ( continued )

25 Microsoft Visual Basic.NET: Reloaded Using the Query Builder to Enter a SELECT Statement ( continued )

26 Microsoft Visual Basic.NET: Reloaded Creating a DataSet

27 Microsoft Visual Basic.NET: Reloaded Creating a DataSet ( continued )

28 Microsoft Visual Basic.NET: Reloaded Creating a DataSet ( continued ) XML (Extensible Markup Language) XML schema definition file defines the tables and fields that make up the data set Schema file is automatically generated by VB.NET Contents of file may be viewed in IDE Contents of dataset can be preview by right clicking the DataAdapter object in the component tray and clicking Preview Data

29 Microsoft Visual Basic.NET: Reloaded Creating a DataSet ( continued )

30 Microsoft Visual Basic.NET: Reloaded Using the Fill Method Method of the DataAdapter object Fills a dataset with data while the application is running

31 Microsoft Visual Basic.NET: Reloaded Binding the Dataset Object to a DataGrid Control Connecting a DataSet object to a control is called “binding” Connected controls are referred to as “bound controls”

32 Microsoft Visual Basic.NET: Reloaded HOW TO…

33 Microsoft Visual Basic.NET: Reloaded Binding the Dataset Object to a DataGrid Control ( continued )

34 Microsoft Visual Basic.NET: Reloaded Reconfiguring the DataAdapter Object

35 Microsoft Visual Basic.NET: Reloaded Reconfiguring the DataAdapter Object ( continued )

36 Microsoft Visual Basic.NET: Reloaded Reconfiguring the DataAdapter Object ( continued )

37 Microsoft Visual Basic.NET: Reloaded Binding the Dataset Object to a Label Control or Text box

38 Microsoft Visual Basic.NET: Reloaded Binding the Dataset Object to a Label Control or Text box ( continued )

39 Microsoft Visual Basic.NET: Reloaded Binding the Dataset Object to a Label Control or Text box ( continued )

40 Microsoft Visual Basic.NET: Reloaded Binding the Dataset Object to a Label Control or Text box ( continued )

41 Microsoft Visual Basic.NET: Reloaded Programming Example – Cartwright Industries Application Carl Simons, the sales manager at Cartwright Industries, records the item number, name, and price of each product the company sells in a database named Items.mdb The database is contained in the VbDotNet\Chap12\Databases folder. Mr. Simons wants an application that the sales clerks can use to enter an item number and then display the item’s price

42 Microsoft Visual Basic.NET: Reloaded Programming Example – Cartwright Industries Application ( continued ) Items.mdb database opened in Microsoft Access. Database contains one table tblItems

43 Microsoft Visual Basic.NET: Reloaded TOE Chart

44 Microsoft Visual Basic.NET: Reloaded User Interface

45 Microsoft Visual Basic.NET: Reloaded Objects, Properties, and Settings

46 Microsoft Visual Basic.NET: Reloaded Tab Order

47 Microsoft Visual Basic.NET: Reloaded Pseudocode btnExit Click event procedure 1. close application frmCartwright Load event procedure 1. fill the dataset with the item numbers and prices from the Items.mdb database

48 Microsoft Visual Basic.NET: Reloaded Code

49 Microsoft Visual Basic.NET: Reloaded Summary Databases created by Microsoft Access are relational databases: Can contain one or more tables Most tables contain a primary key that uniquely identifies each record Data in relational database can be displayed in any order, and you can control the amount of information you want to view Visual Basic.NET uses a technology called ADO.NET to access the data stored in a database

50 Microsoft Visual Basic.NET: Reloaded Summary ( continued ) Connection between a database and an application that uses ADO.NET is only temporary To access data stored in a database, first create and configure a DataAdapter object, which is the link between the application and the Connection object Use an OleDbDataAdapter object and an OleDbConnection object in applications that access Microsoft Access databases

51 Microsoft Visual Basic.NET: Reloaded Summary ( continued ) DataAdapter, Connection, and DataSet objects are stored in component tray Use SQL SELECT statement to specify fields and records for a dataset Query Builder provides a convenient way to create a SELECT statement Dataset contains data you want to access from the database Data specified in SELECT statement associated with DataAdapter object

52 Microsoft Visual Basic.NET: Reloaded Summary ( continued ) Use DataAdapter object’s Fill method to fill a dataset with data while an application is running Users view data stored in a dataset through controls that are bound to DataSet object Use DataGrid control to display records contained in a dataset When you change the SELECT statement associated with a DataAdapter object, you must regenerate the dataset