MDAC 2.5 SDK - ADO


 

What's New in ADO

See Also

The following new features, new reference topics, and new and enhanced documentation are included in the ADO 2.5 release.

New Features

Records and Streams

This release of ADO introduces the Record object, which can represent and manage things like directories and files in a file system, and folders and messages in an e-mail system. A Record can also represent a row in a Recordset, although Record and Recordset objects have different methods and properties.

The new Stream object provides the means to read, write, and manage the binary stream of bytes or text that comprise a file or message stream.

URL Usage

This release also introduces the use of Uniform Resource Locators (URLs), as an alternative to connection strings and command text, to name data store objects. URLs may be used with the existing Connection and Recordset objects, as well as with the new Record and Stream objects.

With this release, ADO supports OLE DB providers that recognize their own URL schemes. For example, the OLE DB Provider for Internet Publishing, which accesses the Windows 2000 file system, recognizes the existing HTTP scheme.

Special Fields for Document Source Providers

A special class of providers, called document source providers, manage folders and documents. When a Record object represents a document, or a Recordset object represents a folder of documents, the document source provider populates those objects with a unique set of fields that describe characteristics of the document. These fields constitute a resource Record or Recordset.

New Reference Topics

The following new properties are included in this release.

Property Description
Charset Indicates the character set into which the contents of a text Stream object should be translated.
EOS Indicates whether the current position is at the end of the stream.
LineSeparator Indicates the binary character to be used as the line separator in text Stream objects.
Mode Indicates the available permissions for modifying data in a Connection, Record, or Stream object.
ParentURL Indicates an absolute URL string that points to the parent Record of the current Record object.
Position Indicates the current position within a Stream object.
RecordType Indicates the type of Record object.
Size Indicates the size of the stream in number of bytes.
Source Indicates the entity represented by the Record object.
State Indicates for all applicable objects whether the state of the object is open or closed.

Indicates for all applicable objects executing an asynchronous method, whether the current state of the object is connecting, executing, or retrieving.

Type Indicates the type of data contained in the Stream object (binary or text).

The following new methods are included in this release.

Method Description
CopyRecord Copies a file or directory, and its contents, to another location.
CopyTo Copies the specified number of characters or bytes (depending on Type) in the Stream object to another Stream object.
DeleteRecord Deletes a file or directory, and all its subdirectories.
Flush Forces the contents of the Stream object remaining in the ADO buffer to the underlying object with which the Stream object is associated.
GetChildren Returns a Recordset whose rows represent the files and subdirectories in the directory represented by this Record.
LoadFromFile Loads the contents of an existing file into a Stream object.
MoveRecord Moves a file, or a directory and its contents, to another location.
Open Opens an existing Record object, or creates a new file or directory.
Open Opens a Stream object to manipulate streams of binary or text data.
Read Reads a specified number of bytes from a binary Stream object.
ReadText Reads specified number of characters from a text Stream object.
SaveToFile Saves the binary contents of a Stream to a file.
SetEOS Sets the position that is the end of the stream.
SkipLine Skips one entire line when reading a text Stream object.
Write Writes binary data to a Stream object.
WriteText Writes a specified text string to a Stream object.

New and Enhanced Documentation

Code Example Topics

The examples have been expanded to contain code examples written in Microsoft Visual C++® and Microsoft Visual J++®. You can copy and paste these code examples into your editor.

Provider Topics

A new topic is included that explains how to use ADO with the OLE DB Provider for Internet Publishing.

Programming with ADO

This new section contains tips and tricks for using ADO with various programming languages. It contains the existing syntax indexes for the Visual C++ Extensions for ADO and ADO/WFC, as well as new information specific to developers using Microsoft Visual Basic®, Microsoft Visual Basic® Scripting Edition, Microsoft JScript®, Microsoft Visual C++, or Microsoft Visual J++.