Ajith Prabhakar’s Weblog

A beginner’s guide to Documentum

Registered Tables in Documentum

Posted by Ajith Prabhakar on January 24, 2008


Registered tables are the tables that are present database which are registered in Documentum, so that it can be accessed using DQL. Basically Registered tables are used when the application needs to access data from the RDBMS within the Documentum. This can be either a Table or a View.  The Scenarios where I mostly used registered tables are for providing value assistance for Object attributes.  I am not getting into too much of details about Value Assistance here, Value assistance is a list of values that a client program (such as Webtop or a Custom WDK Application) displays at runtime for an object attribute. A user can select a value from this list (or, if allowed, add a new one to it). You can set the Value assistance for an Attribute using DAB (Documentum Application Builder).

As I mentioned above uou can register a Table or a view as a Registered Table, The Registered tables are stored as dm_registered objects in repositories. This extends dm_sysobject. And the r_object_id of this type always starts with 19. The following table lists the attributes of dm_registered

Name Info Description
column_count Integer  – Single Number of columns in the table.
column_datatype string(64) – Repeating List of the datatypes of the columns.
column_length. integer R Lengths of the columns that have a string data type
column_name. string(64) – Repeating List of the names of the columns in the table
group_table_permit integer  – Single Defines the RDBMS table permit level assigned to the registered table’s group.
is_key. Boolean Repeating Indicates if an index is built on the column
owner_table_permit integer  – Single Defines the RDBMS table permit level assigned to the registered table’s owner
synonym_for string(254) – Repeating Name of the table in the underlying RDBMS (can be an Oracle table synonym, or an MS SQL Server or Sybase table alias)
table_name string(64) Single Name of the table.
table_owner string(64) Single Name of the owner of the RDBMS table (the person who created the RDBMS table).
world_table_permit integer  – Single Defines the RDBMS table permit level assigned to the world

You should either own the table or have super user privileges to register a table. And since this object is linked with /system cabinet you should have write permission on /system cabinet. This is applicable only if the folder security is enabled in Repository

You cannot version a dm_registered object. And also the changes made to the table are not automatically updated in dm_registered object.  So if any changes has been made to the structure of the table or view you should unregister it first and register the table again with changes.

How to Register a Table?

Use the following DQL to register a table. REGISTER TABLE [owner_name.]table_name (column_def {,column_def}) [[WITH] KEY (column_list)][SYNONYM [FOR] ‘table_identification‘] This DQL will return the r_object_id of the newly created dm_registered object. In this owner_name is the name of the table owner. table_name is the name of the RDBMS table. column_def defines the columns in the registered table.

column_def arguments should have following syntax column_name datatype [(length)] the valid values for types are float, double, integer, int, char, character, string, date, time.

Length should be specified for character, char, or string data type.

column_list Identifies the columns in the table on which indexes have been built. column_list is usually separated with commas. table_ identification is the name of the table in the Database Example:

REGISTER TABLE “hr.users” (first_name CHAR(30), last_name (char 40), emp_id INT)KEY (“emp_id”)

Granting Rights

You need to give the permission to the users to access the registered tables.  The values for various permission levels are as follows 0 (None): No access 1 (Select): The user can retrieve data from the registered table 2 (Update): The user can update existing data in the registered table4 (Insert): The user can insert new data into the registered table8 (Delete): The user can delete rows from the registered table If a user wants update and insert permissions the value should be 2+4 = 6 , The repository owner also should have the same level of permission in the underlying database to grand those permission to those users. Granting Rights full permission to users in the above example

update dm_registered object set world_table_permit = 15 where object_name = ‘users’;

update dm_registered object set owner_table_permit = 15 where object_name =  ‘users’;

update dm_registered object set group_table_permit = 15 where object_name = ‘users’;

How to Unregister a Table?

Use the following DQL to Unregister a Table.

UNREGISTER [TABLE] [owner_name.]table_name In this owner_name is the name of the table owner. table_name is the name of the RDBMS table. You should be the owner of table or super user to do this

Accessing Data from Registered Table

Just like in RDBMS you can access registered table using the following syntax

Select [ATTRIBUTES] from dm_dbo.[REGISTERED_TABLE_NAME] where [CLAUSE]

The Operations such as update/ delete also has the same RDBMS syntax that’s used for a ordinary SQL, Only difference is prefixing dm_dbo to the table name

Example:
Select first_name, last_name, emp_id from dm_dbo.users ;

Updating Data in a Registered Table

Example
Update dm_dbo.users set first_name=’John’ where first_name=’Smith’

Deleting from a Registered Table

Example

Delete from dm_dbo.users  where first_name=’Smith’

Download this note on Registered Table (PDF)

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