Re: Is it safe to use DEFAULT currval() - Mailing list pgsql-general

From Tom Lane
Subject Re: Is it safe to use DEFAULT currval()
Date
Msg-id 6626.1064684440@sss.pgh.pa.us
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In response to Is it safe to use DEFAULT currval()  (Richard Huxton <dev@archonet.com>)
Responses Re: Is it safe to use DEFAULT currval()
List pgsql-general
Richard Huxton <dev@archonet.com> writes:
> CREATE TABLE foo (
>   id       SERIAL,
>   blah     text,
>   tracking int4 DEFAULT currval('foo_id_seq')
>   PRIMARY KEY (id)
> );

> Now - it works, but is that a design feature or just luck?

You're essentially assuming that the column expressions for an INSERT
will be evaluated left-to-right.  That's true at the moment, and I don't
see any foreseeable reason why we'd change it, but it surely is an
implementation dependency that could bite you someday.

            regards, tom lane

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