The Novell Controls for ActiveX and Visual Basic:
Searching NDS Field Values

In the previous article I talked about the hierarchy of containers in a directory (typically, Organizations and Organizational Units). These containers may contain entries and other containers.

Entries are data structures of a specific type or Layout. For example, the layout for Printer entries specifies that directory entries that represent printer objects will have fields for the name of the print queue(s) that the printer services, the name of the print server that manages the printer, and so on. The layout specifies the type of data that can be associated with a printer. An instance of a Printer object contains data pertaining to a specific printer.

Each Field also has a data type, called the Field Type. There are four simple field types:

• Boolean
• Date
• Long
• String

There are also nine predefined structure field types, and it is possible to define new structure field types. The predefined structure field types are:

• NWACL. An Access Control List (ACL). Determines which operations a subject entry can perform on another entry. An ACL is the key component in determining Directory access control.
• NWEMailAdress. Represents an email address.
• NWNetAddress. Represents a network address.
• NWOctetString. Represents a byte string whose value is not interpreted by the Directory.
• NWPath. Represents a file system path.
• NWPostalAddress. Specifies address information for physical delivery of postal messages.
• NWStream. Contains binary data that is (like an NWOctetString) not interpreted by the Directory. Usually used to store large amounts of data, as with graphic or audio files.
• NWTimeStamp. Marks the time when an event occurred or will occur.
• NWTypedName. Represents a level and an interval associated with an entry.

The documentation for the NWDir control (available on the Web at http://developer.novell.com) has more information about the properties of structure field types.

Besides having a field type, fields can also be single-valued or multi-valued. For example, Group entries have a Member field that is a multi-valued field of type String. The Member field contains the full names of User entries that have membership in the group.