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1. 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. Objectives ( continued ). Create a dataset
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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 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 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 Microsoft Visual Basic .NET: Reloaded
Database Terminology (continued) Microsoft Visual Basic .NET: Reloaded
Database Terminology (continued) 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 Microsoft Visual Basic .NET: Reloaded
ADO.NET (continued) Microsoft Visual Basic .NET: Reloaded
ADO.NET (continued) Microsoft Visual Basic .NET: Reloaded
Creating and Configuring a DataAdapter Object Microsoft Visual Basic .NET: Reloaded
Creating and Configuring a DataAdapter Object (continued) Microsoft Visual Basic .NET: Reloaded
Creating and Configuring a DataAdapter Object (continued) Microsoft Visual Basic .NET: Reloaded
Creating and Configuring a DataAdapter Object (continued) Microsoft Visual Basic .NET: Reloaded
Creating and Configuring a DataAdapter Object (continued) Microsoft Visual Basic .NET: Reloaded
Creating and Configuring a DataAdapter Object (continued) 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 Microsoft Visual Basic .NET: Reloaded
HOW TO… Microsoft Visual Basic .NET: Reloaded
HOW TO… (continued) Microsoft Visual Basic .NET: Reloaded
Using the Query Builder to Enter a SELECT Statement Microsoft Visual Basic .NET: Reloaded
Using the Query Builder to Enter a SELECT Statement(continued) Microsoft Visual Basic .NET: Reloaded
Using the Query Builder to Enter a SELECT Statement(continued) Microsoft Visual Basic .NET: Reloaded
Using the Query Builder to Enter a SELECT Statement (continued) Microsoft Visual Basic .NET: Reloaded
Using the Query Builder to Enter a SELECT Statement (continued) Microsoft Visual Basic .NET: Reloaded
Using the Query Builder to Enter a SELECT Statement (continued) Microsoft Visual Basic .NET: Reloaded
Using the Query Builder to Enter a SELECT Statement (continued) Microsoft Visual Basic .NET: Reloaded
Creating a DataSet Microsoft Visual Basic .NET: Reloaded
Creating a DataSet (continued) 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 Microsoft Visual Basic .NET: Reloaded
Creating a DataSet (continued) Microsoft Visual Basic .NET: Reloaded
Using the Fill Method • Method of the DataAdapter object • Fills a dataset with data while the application is running 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” Microsoft Visual Basic .NET: Reloaded
HOW TO… Microsoft Visual Basic .NET: Reloaded
Binding the Dataset Object to a DataGrid Control (continued) Microsoft Visual Basic .NET: Reloaded
Reconfiguring the DataAdapter Object Microsoft Visual Basic .NET: Reloaded
Reconfiguring the DataAdapter Object (continued) Microsoft Visual Basic .NET: Reloaded
Reconfiguring the DataAdapter Object (continued) Microsoft Visual Basic .NET: Reloaded
Binding the Dataset Object to a Label Control or Text box Microsoft Visual Basic .NET: Reloaded
Binding the Dataset Object to a Label Control or Text box (continued) Microsoft Visual Basic .NET: Reloaded
Binding the Dataset Object to a Label Control or Text box (continued) Microsoft Visual Basic .NET: Reloaded
Binding the Dataset Object to a Label Control or Text box (continued) 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 Microsoft Visual Basic .NET: Reloaded
Programming Example – Cartwright Industries Application (continued) • Items.mdb database opened in Microsoft Access. Database contains one table tblItems Microsoft Visual Basic .NET: Reloaded
TOE Chart Microsoft Visual Basic .NET: Reloaded
User Interface Microsoft Visual Basic .NET: Reloaded
Objects, Properties, and Settings Microsoft Visual Basic .NET: Reloaded
Tab Order 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 Microsoft Visual Basic .NET: Reloaded
Code 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 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 Microsoft Visual Basic .NET: Reloaded