Re: Any limitation in size for return result from SELECT?

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От Joe Conway
Тема Re: Any limitation in size for return result from SELECT?
Дата
Msg-id 3E617D7F.1010600@joeconway.com
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Ответ на Any limitation in size for return result from SELECT?  ("Natasa Bulatovic" <n.bulatovic@zim.mpg.de>)
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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



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