Re: Selecting top N percent of records.
| От | Brent Wood |
|---|---|
| Тема | Re: Selecting top N percent of records. |
| Дата | |
| Msg-id | 4CBC72640200007B00030A45@gwia.niwa.co.nz обсуждение исходный текст |
| Ответ на | Selecting top N percent of records. (Tim Uckun <timuckun@gmail.com>) |
| Список | pgsql-general |
Something like this should work - (but is untested), and does require the extra subquery, so there may be a more efficient way?
However, off the top of my head:
select a,b,c
from table
where <where clause>
order by c desc
limit (select count(*)/10 from table where <same where clause>);
where c is the no of sales column
>>> Tim Uckun <timuckun@gmail.com> 10/18/10 3:40 PM >>>
Is there a way to select the top 10% of the values from a column?
For example the top 10% best selling items where number of sales is a column.
Thanks.
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However, off the top of my head:
select a,b,c
from table
where <where clause>
order by c desc
limit (select count(*)/10 from table where <same where clause>);
where c is the no of sales column
Brent Wood
DBA/GIS consultant
NIWA, Wellington
New Zealand
DBA/GIS consultant
NIWA, Wellington
New Zealand
>>> Tim Uckun <timuckun@gmail.com> 10/18/10 3:40 PM >>>
Is there a way to select the top 10% of the values from a column?
For example the top 10% best selling items where number of sales is a column.
Thanks.
--
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To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
NIWA is the trading name of the National Institute of Water & Atmospheric Research Ltd.
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