Re: short ciruit logic of plpgsql in 8.2

This keeps biting me.  In a trigger function for INSERT OR UPDATE if you try

IF TG_OP = 'UPDATE' AND OLD.foo = 'bar' THEN
...

it will blow up on inserts because there is no OLD.  I always expect
this to short circuit and am always disappointed.  Easy fix, of
course...

IF TG_OP = 'UPDATE' THEN
        IF OLD.foo = 'bar' THEN
...

In case this was what the OP was asking about in particular, it still
happens to me in 8.2

- Ian


On 5/17/07, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Richard Broersma Jr <rabroersma@yahoo.com> writes:
> > Does anyone know if logic operations in plpgsql are short circuited in 8.2?
>
> They are often optimized, but if you expect "short circuiting" following
> exactly the rules of, say, C, you are likely to be disappointed.  See
> the manual:
>
> http://www.postgresql.org/docs/8.2/static/sql-expressions.html#SYNTAX-EXPRESS-EVAL
>
>                         regards, tom lane
>
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