ADO 2.5

The ADO Object Model

ADO requires only nine objects and four collections to provide its entire functionality. The following table introduces them.

Object or Collection Description
Connection 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. Depending on the functionality supported by the provider, some collections, methods, or properties of a Connection object may not be available.
Command object Used to define a specific command, such as a SQL query, intended to run against a data source.
Recordset object Represents the entire set of records from a base table or the results of an executed command. All Recordset objects consist of records (rows) and fields (columns).
Record object Represents a single row of data, either from a Recordset or from the provider. This record could represent a database record or some other type of object such as a file or directory, depending upon your provider.
Stream object Represents a stream of binary or text data. For example, an XML document can be loaded into a stream for command input or returned from certain providers as the results of a query. A Stream object can be used to manipulate fields or records containing these streams of data.
Parameter object Represents a parameter or argument associated with a Command object, based on a parameterized query or stored procedure.
Field object Represents a column of data with a common data type. Each Field object corresponds to a column in the Recordset.
Property object Represents a characteristic of an ADO object that is defined by the provider. ADO objects have two types of properties: built-in and dynamic. Built-in properties are those properties implemented in ADO and immediately available to any new object. The Property object is a container for dynamic properties, defined by the underlying provider.
Error object Contains details about data access errors that pertain to a single operation involving the provider.
Fields collection Contains all the Field objects of a Recordset or Record object.
Properties collection Contains all the Property objects for a specific instance of an object.
Parameters collection Contains all the Parameter objects of a Command object.
Errors collection Contains all the Error objects created in response to a single provider-related failure.

The following figures show the ADO objects and their collections. Click an object or collection for more information from the ADO Programmer's Reference.















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