On 2013-05-02 17:32, Karol Trzcionka wrote:
W dniu 02.05.2013 17:17, Tom Lane pisze:
It should in any case be possible to do this without converting them
to reserved words; rather the implementation could be that those table
aliases are made available when parsing the UPDATE RETURNING
expressions. (This is, in fact, the way that rules use these names
now.) Probably it should work something like "add these aliases if
they don't already exist in the query", so as to avoid breaking
existing applications. I don't really see a lot of value in hacking
the behavior of either INSERT RETURNING or DELETE RETURNING.
what should happened in statement:
UPDATE old SET foo=foo+1 RETURNING old.foo;
If it returns old value, it'll break capability. If it returns new value
(as now), there is no possibility to get old value (and user cries
because of broken feature).
In Tom's proposal that would give you the "new" value.
Personally I would maybe prefer reserving NEW/OLD, but if we go through
with Tom's idea, this should work:
UPDATE old myold SET foo=foo+1 RETURNING myold.foo, old.foo;
What I'm more interested in is: how can we make this feature work in
PL/PgSQL where OLD means something different?
Regards,
Marko Tiikkaja
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