DevWebPro

DQL is the language used to query Documentum, which is a content management system used to create, manage, deliver, and archive all types of content from text documents and spreadsheets to digital images, HTML, and XML components.

Contents

• Define DQL

• Behind the scenes

• Describe a SELECT statement

• Describe how search conditions are specified in a WHERE clause

• Using DQL to search a specific cabinet/folder location

• Describe the DQL REGISTER statement

DQL (Documentum Query Language) is a query language which allows you to do very complex queries involving:

1. Property searches

2. Searches for words and phrases within documents

3. Other specialized searching capabilities added for document and content management

DQL uses syntax that is a superset of ANSI-standard SQL (Structured Query Language)

• In fact, part of your DQL statements are translated automatically into SQL before being executed by the eContent Server

Behind the Scenes

• A DQL query is sent to the eContent Server using one of four API methods readquery, execquery, query, or cachequery

• A DQL engine on eContent Server generates

- SQL queries for the RDBMS

- Verity queries for the full-text search engine

The results of the query are stored on the server in a non-persistent collection object. Typically, a Documentum client will automatically present the results of the query to the user in some useful way.

Alternatively, a Developer may want to use the resulting collection object or manipulate the results programmatically.

Basic Select Statement

Select (list the properties you want returned)

>From (list the type of objects you want searched)

Using WHERE clause

Allows the search to be narrowed by imposing search conditions on your Query

select [all | distinct] value [as name] {,value [as name] } from
source_list [(all)]
...
[where qualification ]

Eg : SELECT object_name, title FROM dm_document WHERE FOLDER
(ID('0b9af3ce800001ff')) AND title LIKE '%SOP%'

Searching folders and cabinets

The scope of the search can be specified as folder and cabinet in the where clause to provide a way to search the cabinet/folder hierarchy.

Eg : select object_name from dm_document where folder('/Sales')

REGISTER statement

• Registers an RDBMS table so the eContent Server can "see" it

• Allows access to data in an existing RDBMS table that may be

- created to support additional application data

- part of another application

- owned by someone else

• Does not verify that the table or its columns exist

• All columns in a table need not be registered

• Creates a dm_registered object in the System cabinet which provides a description of the table and user access to it

REGISTER permissions

• Only the Docbase owner with a SUPERUSER privilege can register a table from within Documentum.

• To register a table, you must have at least READ permission on the table (through the RDBMS grant command).

• The eContent Server account (installation owner) needs the appropriate RDBMS privileges on the table to perform different operations on rows in the table.