Search Postgresql Archives

Re: Using null or not null in function arguments

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 23/01/2009 11:16, Igor Katson wrote:

> How do I write a function without complex logic, which will do:
> a) If the input argument is NULL, then the corresponding select
> statement will change from
> 
> column = arg
> to
> column IS NULL

You could build your statement dynamically as a string, then execute it
using EXECUTE:

http://www.postgresql.org/docs/8.3/static/plpgsql-statements.html#PLPGSQL-STATEMENTS-EXECUTING-DYN


> b) If the input argument is NULL, then the corresponding select
> statement will be removed, so if it was not written.

Likewise - something like

  if i_city_id is null then
    ... build statement...
    ... execute statement ...
  end if;

HTH,

Ray.


------------------------------------------------------------------
Raymond O'Donnell, Director of Music, Galway Cathedral, Ireland
rod@xxxxxx
Galway Cathedral Recitals: http://www.galwaycathedral.org/recitals
------------------------------------------------------------------

-- 
Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]
  Powered by Linux