| From: | Filip Rembiałkowski <plk(dot)zuber(at)gmail(dot)com> |
|---|---|
| To: | Jon Smark <jon(dot)smark(at)yahoo(dot)com> |
| Cc: | "pgsql-general(at)postgresql(dot)org" <pgsql-general(at)postgresql(dot)org> |
| Subject: | Re: Let-bindings in SQL statements |
| Date: | 2012-01-26 19:18:10 |
| Message-ID: | CAP_rwwk3VAU7YLAy+vO1OY0R4f0JhkES-ojLufvWsRvqMs3X1w@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-general |
On Thu, Jan 26, 2012 at 3:37 PM, Jon Smark <jon(dot)smark(at)yahoo(dot)com> wrote:
> Hi,
>
> Is it possible to do the equivalent of let-bindings in a pure SQL function?
> I have a SELECT that invokes "now" multiple times. It would be nicer
> to do it only once and reuse the value. Something like this:
>
> LET right_now = SELECT now () IN
> SELECT * FROM my_table WHERE right_now >= start AND ...
>
> In PL/pgSQL this is easy, but I wonder about SQL...
>
>
WITH param AS ( select now() as p_start, somefunc() as p_something )
SELECT * FROM param,my_table WHERE right_now >= param.p_start AND ...
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