Re: Question about WHERE CASE

From: Martin Stöcker <martin(dot)stoecker(at)stb-datenservice(dot)de>
To: pgsql-sql(at)lists(dot)postgresql(dot)org
Subject: Re: Question about WHERE CASE
Date: 2019-09-05 11:42:57
Message-ID: da8bed3e-b178-a788-075e-93c3cbfb8b88@stb-datenservice.de
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-sql


Hi,

where requires a boolean expression, for instance
select * from stuff where true;

Hence "CASE WHEN $1=dir THEN TRUE ELSE metadir=$1 END" returns a boolean
value everything is fine.

Regards martin

Am 05.09.2019 um 13:04 schrieb Mike Martin:
> I have come across the following construct which works in postgres
>
> WHERE CASE WHEN $1=dir THEN TRUE ELSE metadir=$1 END
>
> via
> (https://stackoverflow.com/questions/49859153/filter-with-yes-no-and-all-in-postgres)
> |casewhen('yes'=lower($1))then(phone_number
> isnotnull)when('no'=lower($1))then(phone_number isnull)elsetrue end |
> |I was always under the impression that a case expression could only
> be on the right side of a where expression ie: |
> |WHERE fieldname=<cse expression> |
> |Is this a postgres extention, cant find any documentation on this |
> |thanks |
> |Mike |

--

Widdersdorfer Str. 415, 50933 Köln; Tel. +49 / 221 / 9544 010
HRB Köln HRB 75439, Geschäftsführer: Dr. Dirk Goldner, ppa. Melanie Lillich

In response to

Browse pgsql-sql by date

  From Date Subject
Next Message Tom Lane 2019-09-05 13:46:30 Re: Question about WHERE CASE
Previous Message Mike Martin 2019-09-05 11:04:39 Question about WHERE CASE