different between || and && in a statement

Hi,

I hope theis is the last question for the next time:

1st statement:

SELECT (sum(case when dict.word = 'museum' then 1 else 0 end)
&& sum(case when dict.word = 'immer' then 1 else 0 end)) as qu , dict.url_id
^^ FROM dict, url
WHERE url.rec_id = dict.url_id
AND url.url LIKE '%%'
AND dict.word in ('museum','immer')
GROUP BY dict.url_id
HAVING sum(case when dict.word = 'museum' then 1 else 0 end) &&
sum(case when dict.word = 'immer' then 1 else 0 end) > 0 ^^

The result is:

ERROR: Unable to identify an operator '&&' for types 'int4' and 'int4'
You will have to retype this query using an explicit cast

but if a do it with :

SELECT (sum(case when dict.word = 'museum' then 1 else 0 end)
|| sum(case when dict.word = 'immer' then 1 else 0 end)) as qu , dict.url_id
^^ FROM dict, url
WHERE url.rec_id = dict.url_id
AND url.url LIKE '%%'
AND dict.word in ('museum','immer')
GROUP BY dict.url_id
HAVING sum(case when dict.word = 'museum' then 1 else 0 end) ||
sum(case when dict.word = 'immer' then 1 else 0 end) > 0 ^^

.... all is OK

Whats the different between the logical expression && and || and is there
a way to get && working?

Thanks for any hints. I hope the isn't a stupid question.

Christian

--
Christian Guenther Kunsthistoriker
Fax: +49 030 4464152 E-mail: cg(at)kunst-und-kultur(dot)de
Tel: +49 030 4442931 http://kunst-und-kultur.de/
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