Question

以下查询提供了特定年份的名称，id，已订阅，开张，关门，总计明细，即posted_date是查询的输入。

select la.name,la.id,la.parent_id,la.is_group,tb1.opening op_1,tb1.closing cl_1,
coalesce((select sum(j.amount) from journal j,voucher v , ledger_account le where j.voucher_id=v.id and le.id=j.ledger_account_id and la.id=le.id and
 v.posted_date::date>='2020-04-01' and v.posted_date::date<='2021-03-31'),0) balance_2020
from ledger_account la left join trialb tb1 on tb1.ledger_account_id=la.id and tb1.fy_id=1

上面的查询给出了2020年的总数据和余额，例如：如果我需要2005年的余额，则需要再次粘贴以下逻辑

coalesce((select sum(j.amount) from journal j,voucher v , ledger_account le where j.voucher_id=v.id and le.id=j.ledger_account_id and la.id=le.id and v.posted_date::date>='2020-04-01' and v.posted_date::date<='2021-03-31'),0) balance_2020

，并将v.posted日期和列名更改为
v.posted_date :: date> ='2005-04-01'和v.posted_date :: date <='2006-03-31'），0）balance_2005 等，将近15次直到2020年为止的总余额，查询的规模每年都在增加，所需的时间也在不断增加。

那么，是否有任何替代或可能的方法，可以根据需要根据提供给查询的输入动态地生成balance_2005，balance_2006 ..等列？

Answer 1

将子查询移至from子句，并使用条件聚合获得各种总和：

select
  la.name,
  la.id,
  la.parent_id,
  la.is_group,
  tb1.opening op_1,
  tb1.closing cl_1,
  sums.balance_2018,
  sums.balance_2019,
  sums.balance_2020
from ledger_account la
left join trialb tb1 on tb1.ledger_account_id = la.id and tb1.fy_id = 1
left join
(
  select
    j.ledger_account_id,
    sum(case when v.posted_date::date >= date '2018-04-01' and v.posted_date::date <= date '2019-03-31') then j.amount else 0 end) as balance_2018,
    sum(case when v.posted_date::date >= date '2019-04-01' and v.posted_date::date <= date '2020-03-31') then j.amount else 0 end) as balance_2019,
    sum(case when v.posted_date::date >= date '2020-04-01' and v.posted_date::date <= date '2021-03-31') then j.amount else 0 end) as balance_2020
  from journal j
  join voucher v on v.id = j.voucher_id
  group by j.ledger_account_id
) sums on sums.ledger_account_id = la.id
order by la.name;

如果您不希望使用固定的年份，则不能使用列，而必须使用行。您需要进行从日期到会计年度的计算，但这只是从中减去三个月。

select
  la.name,
  la.id,
  la.parent_id,
  la.is_group,
  tb1.opening op_1,
  tb1.closing cl_1,
  sums.fiscal_year
  sums.balance
from ledger_account la
left join trialb tb1 on tb1.ledger_account_id = la.id and tb1.fy_id = 1
left join
(
  select
    j.ledger_account_id,
    extract(year from v.posted_date - interval '3 months') as fiscal_year
    sum(j.amount) as balance
  from journal j
  join voucher v on v.id = j.voucher_id
  group by j.ledger_account_id, extract(year from v.posted_date - interval '3 months')
) sums on sums.ledger_account_id = la.id
order by la.name, sums.fiscal_year;

让您的应用循环处理帐户的年度数据。

如果您想避免获得非常大的结果集并将其限制为某些年份，则可以添加此条件，例如

  ...
  where extract(year from v.posted_date - interval '3 months') between 2010 and 2020
  group by j.ledger_account_id, extract(year from v.posted_date - interval '3 months')
  ...

动态生成postgres子查询中的列

1 个答案: