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Just curious, how are you planning to display the histogram?
Are you allowed to use application code (C/C++/Perl, etc..) to generate
the
histogram? Personally, SQL is great for showing the data but not good for
making graphs with data you can show.
On Wed, Apr 30, 2008 at 5:01 PM, Alexy Khrabrov <deliverable@[EMAIL PROTECTED]
>
wrote:
> Greetings -- I have a table of the kind
>
> Ratings:
> id integer
> rating smallint
>
> -- where value can take any value in the range 1 to 5. Now I want to
have
> a statistical table Stats of the form
>
> id integer
> min smallint
> max smallint
> avg real
> r1 integer
> r2 integer
> r3 integer
> r4 integer
> r5 integer
>
> -- how can I create it in one pass over Ratings? I can use min(),
max(),
> avg() for
> insert into stats values (id,select min(rating), max(rating),
avg(rating),
> ...) from ratings
>
> -- but what to do for r1,..,r5, short of subselects (select
count(rating)
> from ratings where stats.id=ratings.id) for each, which is an overkill?
>
> Also, if a table Stats already exists with some more columns, and we
need
> to do an update, not insert, for the above, how would that work --
>
> update stats set min=min(ratings), ... from ratings where stats.id=
> ratings.id -- how do we do the histogram in this case, where the id is
> fixed explicitly?
>
> Cheers,
> Alexy
>
> --
> Sent via pgsql-sql mailing list (pgsql-sql@[EMAIL PROTECTED]
)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-sql
>
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Just curious, how are you planning to display the histogram? <br>Are you
allowed to use application code (C/C++/Perl, etc..) to generate the
histogram? Personally, SQL is great for showing the data but not good for
making graphs with data you can show.<br>
<br><br><br><div class="gmail_quote">On Wed, Apr 30, 2008 at 5:01 PM,
Alexy Khrabrov <<a
href="mailto:deliverable@[EMAIL PROTECTED]
">deliverable@[EMAIL PROTECTED]
>>
wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid
rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Greetings -- I have a table of the kind<br>
<br>
Ratings:<br>
id integer<br>
rating smallint<br>
<br>
-- where value can take any value in the range 1 to 5. Now I want to
have a statistical table Stats of the form<br>
<br>
id integer<br>
min smallint<br>
max smallint<br>
avg real<br>
r1 integer<br>
r2 integer<br>
r3 integer<br>
r4 integer<br>
r5 integer<br>
<br>
-- how can I create it in one pass over Ratings? I can use min(),
max(), avg() for<br>
insert into stats values (id,select min(rating), max(rating), avg(rating),
...) from ratings<br>
<br>
-- but what to do for r1,..,r5, short of subselects (select count(rating)
from ratings where stats.id=<a href="http://ratings.id"
target="_blank">ratings.id</a>) for each, which is an overkill?<br>
<br>
Also, if a table Stats already exists with some more columns, and we need
to do an update, not insert, for the above, how would that work --<br>
<br>
update stats set min=min(ratings), ... from ratings where stats.id=<a
href="http://ratings.id"
target="_blank">ratings.id</a> -- how do we do
the histogram in this case, where the id is fixed explicitly?<br>
<br>
Cheers,<br>
Alexy<br><font color="#888888">
<br>
-- <br>
Sent via pgsql-sql mailing list (<a href="mailto:pgsql-sql@[EMAIL PROTECTED]
"
target="_blank">pgsql-sql@[EMAIL PROTECTED]
>)<br>
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</font></blockquote></div><br>
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