The ActiveX Data Object (ADO) Library (CXADO.DLL) provides an easy-to-use, be a high-level interface to provide ease of access to data stored in a wide variety of database sources.   ADO is a Microsoft technology which stands for ActiveX Data Objects ADO and is a Microsoft Active-X component.   The CXADO Libary provides a layer of abstraction between your application and the low-level OLE DB interfaces so that data access can be acheived without having to learn the intricacies of COM or OLE DB.

The current version of the CXADO.DLL library provides the functions that allow a Telecom Engine to establish connections to various database sources and then to excecute queries and commands (including invoking stored procedures) against the tables using Standard Query Language (SQL) statements and to browse and manipulate the returned recordsets.

Not all of the functionality of the ADO is exposed by the CXADO library, but the functions that are provided should provide the mechanisms needed for the vast majority of applications.          If any additional functionality is required that is not currently supported by the CXADO.DLL library (suchs as streams,   stored procedures that return multiple datasets etc.) then it is suggested that the developer write their own middleware application in the language of their choice and communicate with that using a client-server model using the CXSOCKETS.DLL libary.

The entire CXADO.DLL library is implemented using just two ADO objects:   The Connection object and the Recordset object.

Represents a unique session with a data source. In the case of a client/server database system, it may be equivalent to an actual network connection to the server.

An ADO Connection object represents a unique session with a data source, including a DBMS, a file store, or a comma-delimited text file. In the case of a client/server database system, the ADO connection can be an actual network connection to the server.    Data providers represent diverse sources of data such as SQL databases, indexed-sequential files, spreadsheets, document stores, and mail files. Providers expose data uniformly using a common abstraction called the rowset.

ADO is powerful and flexible because it can connect to any of several different data providers and still expose the same programming model, regardless of the specific features of any given provider. However, because each data provider is unique, how your application interacts with ADO will vary by data provider.

Under the CXADO.DLL library, commands and queries are not executed through the connection object itself (which is possible under ADO), instead all commands and queries must be executed through a Recordset object.          Some SQL queries return data as a set of rows in a table (E.g. SELECT query),  whereas other queries excecute commands that do not return data (such as the CREATE TABLE query).        The CXADO.DLL library provides functions that enable both types of queries to be executed on a Recordset object.

The ADO Command object is currently not implemented by the library as most functionality can be acheived through executing commands through the Recordset object (except for executing stored procedures that return multiple recordsets, or that return both recordsets and parameter values).        Note that the Command object may be implemented in future versions if there is a pressing need for it.