Re: Fw: Count rows group by time intervals - Mailing list pgsql-novice

From Oliveiros Cristina
Subject Re: Fw: Count rows group by time intervals
Date
Msg-id f54607780705090750v6989abdcm99b9e798496bb0f4@mail.gmail.com
Whole thread Raw
In response to Re: Fw: Count rows group by time intervals  ("Loredana Curugiu" <loredana.curugiu@gmail.com>)
Responses Re: Fw: Count rows group by time intervals  ("Loredana Curugiu" <loredana.curugiu@gmail.com>)
List pgsql-novice
Funny thing.
In mine, it works...
On mine, If I subtract one date  from the other I get the number of days in between...which is another integer, I guess. and '%'  is the modular operator. Doesnt it work like this on yours?

Which version are you using?

try

SELECT (date - '2007-01-01') % 2
FROM table

to see if you get zeroes and ones .

Cheers,
Oliveiros

2007/5/9, Loredana Curugiu <loredana.curugiu@gmail.com >:
 
You need a query that returns the number of receivers on each theme, in two days intervals, is this correct?

yes, this is correct. Actually the interval in days is variable ( it would specified using PreparedStatemtent ).
Sorry I didn't say from the begining.

Please try something like this. I am not sure if it works, because I don't have a table like yours.
I am assuming  your  table is called table
 
SELECT  a."date",a."theme",a.receiver,COUNT(*)
FROM table a
INNER JOIN table b
ON a."theme" = b."theme" AND a.receiver = b.receiver
WHERE (((b."date" - a."date") = 1) OR (b."date" - a."date") = 0)
GROUP BY a."date",a."theme",a.receiver
HAVING (a."date" - '2007-01-01' ) % 2 = 0
ORDER BY a."date"

The query above it's not working, I've got the following error:
     ERROR:  operator does not exist: interval % integer
     HINT:  No operator matches the given name and argument type(s). You may need to add explicit type casts.




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