Introduction to DQL -Documentum Query Language-
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. |
