tailieunhanh - ADO.NET Databases With .NET Framework

Using Databases With the advent of the .NET Framework, Microsoft decided to update its model for accessing databases, ActiveX Data Objects (ADO) | Using Databases With the advent of the .NET Framework Microsoft decided to update its model for accessing databases ActiveX Data Objects ADO and created . contains several enhancements over the original ADO architecture providing improved interoperability and performance. If you are already familiar with ADO you will notice that the object model of is a little different. For one thing the RecordSet type no longer exists Microsoft has created the TableAdapter and DataSet classes that support disconnected data access and operations allowing greater scalability because you no longer have to be connected to the database all the time. To be fair ADO provided disconnected RecordSets but they were the exception rather than the rule when used by programmers. Therefore your applications can consume fewer resources. With the connection pooling mechanisms of database connections can be reused by different applications thereby reducing the need to continually connect to and disconnect from the database which can be a time-consuming operation. is designed to be easy to use and Visual Studio 2005 provides several wizards and other features that you can use to generate data access code. The Northwind Traders Database Northwind Traders is a fictitious company that sells edible goods with exotic names. The Northwind database contains several tables with information about the goods that Northwind Traders sells the customers they sell to orders placed by customers suppliers that Northwind Traders obtains goods from to re-sell shippers that they can use to send goods to customers and employees who work for Northwind Traders. Figure 23-1 shows all the tables in the Northwind Traders database and how they are related to each other. The tables that you will be using in this chapter are Orders and Products. Figure 23-1 The tables in the Northwind Traders database. Creating the Database Before proceeding further you need to create the .