Creating an ADO Application

The following components and functions are part of the ADO architecture.

Component	Function
Application	Calls ADO objects, collections, methods, and properties to communicate with a data source. Submits SQL statements, and processes result sets.
ADO	Manages communication between an application and the OLE DB provider used by the application.
OLE DB provider	Processes all ADO calls from the application, connects to a data source, passes SQL statements from the application to the data source, and returns results to the application.
Data source	Contains the information used by a provider to access a specific instance of data in a DBMS.

An application that uses ADO to communicate with Microsoft® SQL Server™ 2000 performs the following tasks:

• Connects with a data source.
  
  
• Sends SQL statements to the data source.
  
  
• Processes the results of statements from the data source.
  
  
• Processes errors and messages.
  
  
• Terminates the connection to the data source.

A more complex application written using ADO can also perform the following tasks:

• Use cursors to control location in a result set.
  
  
• Execute stored procedures on a server.
  
  
• Execute user-defined functions on a server.
  
  
• Manage queries that generate multiple result sets.
  
  
• Request commit or rollback operations for transaction control.
  
  
• Perform catalog operations to inquire about the attributes of a result set.
  
  
• Manage long data (text, ntext, and image columns) operations.
  
  
• Perform XML operations using XPath queries, annotated schemas, and Transact-SQL extensions such as FOR XML and OpenXML.

For more information, see Using ADO in Different Development Environments.