[英]Query to separate, then count a field of comma separated values in postgresql
我在postgresql中有一个表,其开始如下:
car_id part_ids total_inventory
------ -------- ----------
10134 101,506,589 50
12236 201,506,101 20
78865 201,399,304 10
我正在尝试编写一个查询和/或视图,该查询和/或视图将逗号分隔每个part_id,将每个part_id的总total_inventory计数在一起,然后将所有part_id包括在这样的单个列中:
part_ids total_inventory
-------- ----------
101 70
506 70
589 50
201 30
399 10
304 10
我试过在part_ids列上使用unnest(string_to_array)以获得最终结果-但运气还不算太高。
有人有想法么? 感谢您的帮助!
附言:这是我的第一个问题-任何建议/编辑,请让我知道
这样的事情应该工作
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
在线示例: http : //rextester.com/NVTCG56767
尝试这个:
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,我创建一个临时表来保存未嵌套的值。
然后,我将part_id分组并对其相关的total_inventory求和。
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