Skip site navigation (1) Skip section navigation (2)

Peripheral Links

Header And Logo

PostgreSQL
| The world's most advanced open source database.

Site Navigation

Search for
  Advanced Search

Re: Replacing IDENTITY with lastval()



Dmitry Samokhin wrote:
Accordind to the release notes, "Use lastval() function to replace IDENTITY on 8.1 or later servers" was introduced in release 8.2.0205. This may cause incorrect results: "<...> assumes that your database does not expect any triggers to fire when the INSERT is executed. If a trigger does fire and if that trigger adds another row to a table, the @@IDENTITY global variable would be set to point to that new Identity value—not the one your INSERT generated. <...> work for simple situations, but not when your database gets more sophisticated".
See "Managing an @@IDENTITY Crisis" on MSDN (http://msdn2.microsoft.com/en-us/library/ms971502.aspx) for more details.

The PostgreSQL documentation states that the lastval() function returns the value most recently returned by nextval in the current session. It works the same way as the @@IDENTITY variable in MSSQL. The currval(...) function returns a value of the explicitly specified sequence, this is exactly what we need.

Please consider to revert the code.

OK I would take care of it in 8.2.0402.

regards,
Hiroshi Inoue



Home | Main Index | Thread Index

Privacy Policy | PostgreSQL Archives hosted by Command Prompt, Inc. | Designed by tinysofa
Copyright © 1996 – 2008 PostgreSQL Global Development Group