Hi David, I had just figured out the sub-query requirement when you replied. So now I've got this working: SELECT * FROM ( SELECT testname,os,arch,build_type,branch,current_status,last_update,rank() OVER (PARTITION BY testname,os,arch,branch,build_type ORDER BY last_update DESC) AS myrank FROM mytable WHERE current_status='FAILED' AND age(now(),last_update) <= INTERVAL '15 days') blah where myrank=2 ; However, I'm getting a bit lost at this point as to what I need to do next. I've been googling on "WITH CTE" and its mostly going over my head. Could you give me more of a hint about this 3rd layer of sub-query? thanks On Wed, Apr 13, 2011 at 10:17 PM, David Johnston <polobo@xxxxxxxxx> wrote: > You need to turn the query with the window function into a sub-query and then in the outer query you can refer to the inner-query's rank() column. ÂThe inner query should effectively get you the last two test results for each context and then you can check to see if any of those failed. > > I have a hunch you might need a third layer of sub-queries to handle the failure aspect of the requirement properly; possibly as part of a "WITH" CTE. ÂYou for sure need to in order to. Properly utilize the rank() function limiting. > > Dave > > On Apr 14, 2011, at 0:52, Lonni J Friedman <netllama@xxxxxxxxx> wrote: > >> Hi David, >> Thanks for your reply. ÂI'm using 8.4.7, so window functions are >> certainly an option, although I've admittedly never used them before. >> I've spent the past few hours reading the dox, and I now have a >> rudimentary understanding of window functions. ÂI tried to compose a >> query based on your suggestion, but I think i'm running up against my >> lack of experience. ÂThis query seems to give me all failures but not >> neccesarily when there are two in a row for a unique group (although >> I'm still not 100% certain its actually returning only last_update >> consecutive rows): >> SELECT testname,os,arch,build_type,branch,current_status,last_update,rank() >> OVER (PARTITION BY testname,os,arch,branch,build_type ORDER BY >> last_update DESC) FROM mytable WHERE current_status='FAILED' AND >> age(now(),last_update) <= INTERVAL '15 days' >> >> However, if I'm understanding how this works, what I really care about >> is when a rank=2 exists, as that's truly when something failed for two >> consecutive last_update's. ÂI thought this might do it, but apparently >> I'm doing it wrong: >> >> SELECT testname,os,arch,build_type,branch,current_status,last_update,rank() >> OVER (PARTITION BY testname,os,arch,branch,build_type ORDER BY >> last_update DESC) FROM mytable WHERE current_status='FAILED' AND >> age(now(),last_update) <= INTERVAL '15 days' AND rank()=2 ; >> ERROR: Âwindow function call requires an OVER clause >> LINE 1: ... age(now(),last_update) <= INTERVAL '15 days' AND rank()=2 ; >> >> How do I restrict the results to only show when rank=2 ? >> >> thanks! >> >> >> On Wed, Apr 13, 2011 at 9:57 AM, David Johnston <polobo@xxxxxxxxx> wrote: >>> If you have the ability to use Window functions you can group (as necessary), order by last_update, and then use rank() to number each test run sequentially. ÂThen you can limit the results to Â( rank() <= 2 AND current_status = 'FAILED' ). >>> >>> David J. >>> >>> -----Original Message----- >>> From: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general-owner@xxxxxxxxxxxxxx] On Behalf Of Lonni J Friedman >>> Sent: Wednesday, April 13, 2011 3:34 AM >>> To: pgsql-general >>> Subject: updating rows which have a common value forconsecutive dates >>> >>> Greetings, >>> I have a table full of automated test data, which continuously has new unique data inserted: >>> >>>  ÂColumn   |      ÂType       | >>> ÂModifiers >>> ----------------+-----------------------------+------------------------- >>> ----------------+-----------------------------+------------------------- >>> ----------------+-----------------------------+----------- >>> Âid       | integer           | not null default >>> nextval('dbltests_id_seq'::regclass) >>> Âtestname    | text            Â| not null >>> Âlast_update  Â| timestamp without time zone | not null default now() >>> Âcurrent_status | text            Â| not null >>> Âos       | text            Â| not null >>> Âarch      | text            Â| not null >>> Âbuild_type   | text            Â| not null >>> Âbranch     | text            Â| not null >>> >>> The 'testname' column contains many different tests, and each unique 'testname' has numerous different associated os,arch,build_type & branch values. ÂFor example, testname='foo' will run on os='Linux',arch='i686',build_type='debug',branch='t38', and also on os='Windows7',arch='x86_64',build_type='release',branch='r40', etc, and there will be many other different testname's with similar permutations of the os,arch,build_type & branch columns. ÂSo for example, there will also be testname='bar' or testname='omega' or testname='sigma' for the other assorted os,arch,build_type & branch permutations. >>> >>> The current_status column is either 'PASSED' or 'FAILED'. >>> >>> What I'm struggling with is how to put together a SQL query which shows me all instances of a given testname permutation >>> (os,arch,build_type,branch) which has a current_status value of 'FAILED' for two or more most recent consecutive 'last_update' values. >>> >>> Suggestions welcome. >>> >>> thanks in advance! -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
