OpenEdge Data Management: DataServer for Microsoft SQL Server

Chapter 7: The DataServer Tutorial
Using computed columns to enable PROGRESS_RECID
support of the ROWID function
Use the following procedures to create PROGRESS_RECID to support the ROWID
function. Note that computed column technology is available only in MS SQL Server
2005 and later versions.
To modify a table to support the ROWID function using a computed column:
1. Add new columns PROGRESS_RECID, PROGRESS_RECID_IDENT_, and
PROGRESS_RECID_ALT_, as shown:
ALTER TABLE table ADD PROGRESS_RECID AS
CASE WHEN PROGRESS_RECID_ALT_ is NULL
THEN PROGRESS_RECID_IDENT_
ELSE PROGRESS_RECID_ALT_
END PERSISTED NOT NULL,
PROGRESS_RECID_IDENT_ bigint identity,
PROGRESS_RECID_ALT_ bigint null default NULL,
CONSTRAINT table#_#table progress_recid UNIQUE(PROGRESS_RECID)
2. If you have already created your schema holder, delete and recreate it.
Migrating RECID-trigger mechanism to RECID computed
column mechanism
Use the following procedure to convert a table that supports the ROWID function from
one that is trigger-enabled to the more reliable computed column-enabled. Computed
column enablement is available only through MS SQL Server 2005 and later.
Note: Prior to performing the following steps, ensure you have backed up the tables
with which you will be working.
To adopt a table to support the ROWID function using computed column from
trigger mechanism:
1. Drop the trigger on INSERT for PROGRESS_RECID column as:
DROP TRIGGER _TI_tbl-name
GO
2. Store the current identity value on the table as follows:
select ident_current('') as old_identity_value
go
316 OpenEdge Data Management: DataServer for Microsoft SQL Server