Je pense que cela correspond au résultat attendu :
select "user", "contact", "barcode", "date", "in", "out","dif"
, sum("in"-"out") over(partition by "user", "contact") as "sum"
from (
select "user", "contact", "barcode", "date", "in", "out","dif"
, lag(dif,1) over(partition by "user", "contact" order by "date" ASC) prevdif
, row_number() over(partition by "user", "contact" order by "date" DESC) rn
from "table1"
where date_trunc('day', "date") <= '2017-06-25' ::date - ( interval '1 week')::interval
and "date" > '2017-06-25'::date - ( interval '2 weeks')::interval
) d
where rn in (1,2) and prevdif is not null
order by 1,2,4 DESC
Résultat :
+----+-------+----------------+---------+---------------------+-----+-----+-----+-----+
| | user | contact | barcode | date | in | out | dif | sum |
+----+-------+----------------+---------+---------------------+-----+-----+-----+-----+
| 1 | USER2 | Guillermo Tole | 987654 | 16.06.2017 05:27:00 | 500 | 420 | 80 | 170 |
| 2 | USER2 | Guillermo Tole | 281460 | 15.06.2017 05:36:00 | 310 | 220 | 90 | 170 |
| 3 | USER3 | Juan Rulfo | 123456 | 15.06.2017 05:37:00 | 450 | 300 | 150 | 150 |
| 4 | USER3 | Pepito Marquez | 346234 | 15.06.2017 05:37:00 | 600 | 360 | 240 | 240 |
+----+-------+----------------+---------+---------------------+-----+-----+-----+-----+
Voir :http://rextester.com/ISHS42170
Pour des conditions telles que "le plus récent", je trouve que l'utilisation de ROW_NUMBER() OVER() est la plus pratique car elle permet de renvoyer la ligne entière de chaque événement "le plus récent", ce qui n'est pas si simple si vous utilisez MAX() et PAR GROUPE. Les résultats "distincts" sont renvoyés en filtrant les lignes ayant la valeur 1 renvoyées par la fonction.
+MODIFIER
Au lieu d'utiliser where rn in (1,2) Je pense qu'une meilleure façon aurait été d'utiliser le code-barres dans les conditions OVER(PARTITION BY...), comme ceci :
select "user", "contact", "barcode", "date", "in", "out","dif"
, sum("in"-"out") over(partition by "user", "contact") as "sum"
from (
select "user", "contact", "barcode", "date", "in", "out","dif"
, lag(dif,1) over(partition by "user", "contact", "barcode" order by "date" ASC) prevdif
, row_number() over(partition by "user", "contact", "barcode" order by "date" DESC) rn
from "table1"
where date_trunc('day', "date") <= '2017-06-25' ::date - ( interval '1 week')::interval
and "date" > '2017-06-25'::date - ( interval '2 weeks')::interval
) d
where rn = 1 and prevdif is not null
order by 1,2,4 DESC
