Search Postgresql Archives

Single Table Report With Calculated Column

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



  I've read some on table partitioning and using nested select statements
with group by, but have not found the syntax to produce the needed results.

  From a table I extract row counts grouped by three columns:

select stream, sampdate, func_feed_grp, count(*) from benthos group
by stream, sampdate, func_feed_grp order by stream, sampdate,
func_feed_group;

And I want to include the proportion of each count based on the total rows
for each stream and sampdate. The totals are obtained with this statement:

select stream, sampdate, count(*) as tot_cnt from benthos group by stream,
sampdate order by stream, sampdate;

  What I do not know how to do is combine the two so the resulting table
contains the columns stream, sampdate, count, proportion. I want to learn
how to build the sub-select to get this result. Joe Celko's 'SQL for
Smarties, 4th Ed.' has a close example in the chapter on table partitioning,
but I could not apply that model to my table.

TIA,

Rich


--
Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general




[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]
  Powered by Linux