Re: Any limitation in size for return result from SELECT? - Mailing list pgsql-sql

From Joe Conway
Subject Re: Any limitation in size for return result from SELECT?
Date
Msg-id 3E617D7F.1010600@joeconway.com
Whole thread Raw
In response to Any limitation in size for return result from SELECT?  ("Natasa Bulatovic" <n.bulatovic@zim.mpg.de>)
List pgsql-sql
Natasa Bulatovic wrote:
> select col1||col2||col3||.....||col100 from table
> 
> However, when the number of concatenated columns is bigger than 22 no
> result is given back (tested in psql, as well as from pgplsql)....
> 
> Most of these columns for the test data are NULL...Datatypes of

Based on your description, I'd guess column 23 is the first null one. If 
you concatenate null with any value, you'll get a null result:

regression=# select 'hello'; ?column?
---------- hello
(1 row)

regression=# select 'hello' || null; ?column?
----------

(1 row)

regression=# select ('hello' || null) is null; ?column?
---------- t
(1 row)

HTH,

Joe



pgsql-sql by date:

Previous
From: Stephan Szabo
Date:
Subject: Re: OUTER JOIN with filter
Next
From: Bruno Wolff III
Date:
Subject: Re: Dynamic SELECT condition