[英]Query to separate, then count a field of comma separated values in postgresql
我在postgresql中有一個表,其開始如下:
car_id part_ids total_inventory
------ -------- ----------
10134 101,506,589 50
12236 201,506,101 20
78865 201,399,304 10
我正在嘗試編寫一個查詢和/或視圖,該查詢和/或視圖將逗號分隔每個part_id,將每個part_id的總total_inventory計數在一起,然后將所有part_id包括在這樣的單個列中:
part_ids total_inventory
-------- ----------
101 70
506 70
589 50
201 30
399 10
304 10
我試過在part_ids列上使用unnest(string_to_array)以獲得最終結果-但運氣還不算太高。
有人有想法么? 感謝您的幫助!
附言:這是我的第一個問題-任何建議/編輯,請讓我知道
這樣的事情應該工作
select p.part_id,
sum(t.total_inventory) as total_inventory
from parts t
cross join lateral unnest(string_to_array(part_ids, ',')::int[]) as p(part_id)
group by p.part_id
在線示例: http : //rextester.com/NVTCG56767
嘗試這個:
WITH X AS
(
SELECT car_id, UNNEST(REGEXP_SPLIT_TO_ARRAY(part_ids, ',')) AS part_ids, total_inventory FROM parts
)
SELECT part_ids, SUM(total_inventory) AS total_inventory FROM X GROUP BY part_ids
ORDER BY total_inventory DESC;
第一步,我創建一個臨時表來保存未嵌套的值。
然后,我將part_id分組並對其相關的total_inventory求和。
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