Microsoft® ActiveX® Data Objects (ADO) is a data access interface used to communicate with OLE DB-compliant data sources, such as Microsoft SQL Server™. Data consumer applications can use ADO to connect to, and retrieve, manipulate, and update data from SQL Server.
Architecturally, ADO is the application-level interface to OLE DB, a library of COM interfaces that enables universal access to diverse data sources. Because ADO is built on top of OLE DB, it benefits from the rich data access infrastructure that OLE DB provides, yet shields the application developer from the necessity of programming COM interfaces. On an everyday basis, developers can use ADO for general purpose access programs in business applications (Accounting, Human Resources, and Customer Management), and OLE DB for tool, utility, or system-level development (development tools and database utilities).
The topics covered in Programming ADO emphasize the use of ADO 2.0 with SQL Server, and are not intended as a general primer in using ADO. The primary source of information on ADO 2.0 is the ADO part of the online Microsoft MSDN™ Library, Microsoft Visual Studio® version 6.0 edition. The ADO sections in the MSDN Library contain ADO getting started topics, and reference topics for each ADO object, collection, property, and method. The ADO DLLs are installed as part of SQL Server Setup in the \Program Files\Common Files\System\ADO directory; no special installation steps are required.