BigQuery SQL 运行算术余额视图

Question

我有 2 个 table 想加入，以便获得下面所需的视图：

Table 1：合同

Contracts*	Quantity
Contract 1	10
Contract 2	20
Contract 3	30

Table 2：交货

Date	Vehicle*	Contracts	Delivered
01/01/2022	Vehicle A	Contract 1	5
02/01/2022	Vehicle B	Contract 1	5
02/01/2022	Vehicle B	Contract 2	10
03/01/2022	Vehicle C	Contract 2	10
03/01/2022	Vehicle C	Contract 3	15

所需视图（显示当前未结数量，以抵消该特定合同的交付）

* - 表示 table

的主键

Date	Vehicle	Contracts	Quantity	Outstanding	Delivered	Balance
01/01/2022	Vehicle A	Contract 1	10	10	5	5
02/01/2022	Vehicle B	Contract 1	10	5	5	0
02/01/2022	Vehicle B	Contract 2	20	20	10	10
03/01/2022	Vehicle C	Contract 2	20	10	10	0
03/01/2022	Vehicle C	Contract 3	30	30	15	15

select

  deliveries.date,
  deliveries.vehicle, 
  contracts.contracts,
  contracts.quantity,
  outstanding (?),
  contracts.quantity - contracts.delivered as delivered
  balance (?)

from contracts
left join deliveries on deliveries.contracts = contracts.contracts

我不知道outstanding和balance的表达式怎么写。

是否涉及sum(quantity - delivered) over (partition by vehicle order by contract)？

Answer 1

考虑以下方法

select date, vehicle, contracts, quantity, 
  quantity - ifnull(sum(delivered) over prev, 0) outstanding, 
  delivered, 
  quantity - delivered - ifnull(sum(delivered) over prev, 0)  balance
from deliveries d 
left join contracts c
using (contracts)
window prev as (partition by contracts order by date rows between unbounded preceding and 1 preceding)

如果应用于您问题中的示例数据 - 输出为

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