How to write a crosstab which returns empty row results

On 12/24/2022 9:03 PM, David Goldsmith wrote:

How do I force "empty rows" to be included in my query output? (I've
tried LEFT JOINing to the row header results, and using CASE
statements; but due to my unfamiliarity w/ using crosstab, I'm not
sure if I've used those correctly in the current context;

Can you give us a head start by showing the query you have now that is
not working.

Extra points if you give simple create/populate statements that
demonstrate the problem.

Hope that helps,
Brad.

Here you go:

SELECT *

FROM crosstab(

'SELECT s.s_n AS Pop

, ad.a_d_y::text AS Yr

, ad.s_a_qty::text --for some Pop all of
these are null for every Yr

FROM st AS s

JOIN s_d_s AS sds ON s.s_id = sds.s_id

JOIN a_d_d AS ad ON sds.sds_id = ad.sds_id

JOIN d_t_l AS dtl ON dtl.dtl_id = sds.dtl_id

WHERE dtl.dtl_id =
''3edcb910-fc0c-49e0-be93-a93e98cb12bb''

AND s.s_id IN (

''9adfe0ee-af21-4ec7-a466-c89bbfa0f750''

,
''8714b2e3-d7ba-4494-a3ed-99c6d3aa2a9c''

,
''45ecb932-ece9-43ce-8095-54181f33419e''

,
''fa934121-67ed-4d10-84b0-c8f36a52544b''

,
''b7d5e226-e036-43c2-bd27-d9ae06a87541''

)

ORDER BY 1,2',

'SELECT DISTINCT a_d_y FROM a_d_d WHERE a_d_y BETWEEN 2017
AND 2021 ORDER BY 1')

AS final_result(Pop TEXT,

"2017" TEXT,

"2018" TEXT,

"2019" TEXT,

"2020" TEXT,

"2021" TEXT

);

A row for each one of the matching s.s_id values should be displayed, even
if all the ad.s_a_qty values for that Yr are NULL; right now, the query
works, but it only returns matching rows for which at least one year has a
non-NULL ad.s_a_qty.

Thanks in advance for your help.

On Sat, Dec 24, 2022 at 7:25 PM Brad White <b55white@gmail.com> wrote:

On Sun, Dec 25, 2022 at 12:25 AM David Goldsmith <d.l.goldsmith@gmail.com>
wrote:

(

''9adfe0ee-af21-4ec7-a466-c89bbfa0f750''

,
''8714b2e3-d7ba-4494-a3ed-99c6d3aa2a9c''

,
''45ecb932-ece9-43ce-8095-54181f33419e''

,
''fa934121-67ed-4d10-84b0-c8f36a52544b''

,
''b7d5e226-e036-43c2-bd27-d9ae06a87541''

)

This is basically your issue - specifying the items you want as individual
items in an IN construct instead of making them into a set (in this case an
array so the set is compactified into a single value):

Something like:

WITH sids (sid_array) AS (
SELECT ARRAY[
'.........',
'........'.
etc...
]
)
SELECT usids.sid, ct.*
FROM (SELECT unnest(sid_array) AS sid FROM sids) AS usids (sid)
LEFT JOIN crosstab( format($$SELECT ... s.s_id = ANY(%L) ...$$, (SELECT
sids.sid_array::text FROM sids) ) AS ct ( pop text, YYYY text, etc... ) ON
usids.sid = ct.pop

David J.

Thanks, David. There's a lot of stuff i'm not familiar with in there: I
don't suppose you know of a tutorial they covers this?

On Sun, Dec 25, 2022 at 8:46 AM David G. Johnston <
david.g.johnston@gmail.com> wrote:

*That* covers this.

On Sun, Dec 25, 2022 at 8:56 AM David Goldsmith <d.l.goldsmith@gmail.com>
wrote: