Re: generate_series with left join

On Wed, 2006-06-28 at 13:34 -0500, Aaron Bono wrote:

> select
>     year_list.year,
>     count(one.*),
>     count(two.*)
> from (
>     select years
>     from generate_series(2006,2009) as years
> ) year_list
> left outer join mytable as one on ( 
>     date_part('year', one.date) = year_list.years
>     and one.cause = 1
> )
> left outer join mytable as two on (
>     date_part('year', two.date) = year_list.years
>     and two.cause = 2
> )
> group by
>     year_list.year
> ;
> 
> 
> select
>     year_list.year,
>     mytable.cause,
>     count(mytable.*)
> from (
>     select years
>     from generate_series(2006,2009) as years
> ) year_list
> left outer join mytable on ( 
>     date_part('year', mytable.date) = year_list.years
> )
> group by
>     year_list.year,
>     mytable.cause
> ;
> 
Aaron, 
Thank you so much for your reply.
However, the 2 examples you provided have "weird" outputs:

The first:years |  count  |  count
-------+---------+--------- 2009 |       0 |       0 2008 |       0 |       0 2007 |       0 |       0 2006 | 7802080 |
7802080
(4 rows)

Time: 87110.753 ms  << yay.


The second:
years | cause | count
-------+---------+------- 2009 |         |     0 2008 |         |     0 2007 |         |     0 2006 |       6 |     1
2006|       1 |  4030 2006 |       2 |  1936 2006 |       3 |  4078 2006 |     100 |  3159 2006 |      98 |  2659 2006
|     99 |  2549
 

My need is really to only group the counts of where cause=1 and cause=2
for each year, none of the others.

> I think one of the problems many people have is the writing of their
> SQL in paragraph form.  It makes the SQL really hard to read and even
> harder to understand and debug.  Formatting your SQL like I did above
> may make it easier to see what is wrong. 

Indeed. Note taken, i'll improve my formatting.

\\pb


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