使用有效日期子句从货币表计算 MS SQL 中的汇率

Question

我有一个具有以下结构的货币表，其中每种交易货币的汇率以参考货币（即欧元）维护，但不一定以其他货币为单位。

bcur|curr | effectivedt|Expressinbase|rate
EUR |SAR  |01/04/2020  |1        |12.23
EUR |SAR  |01/05/2020  |1        |12.27 
EUR |SAR  |01/06/2020  |1        |12.29
EUR |INR  |01/04/2020  |1        |77.78
EUR |INR  |01/05/2020  |1        |77.90
EUR |USD  |01/04/2020  |1        |1.34
EUR |GBP  |01/04/2020  |1        |23
EUR |GBP  |01/05/2020  |1        |32
USD |SAR  |01/04/2020  |1        |45
USD |SAR  |01/05/2020  |1        |54
USD |GBP  |01/04/2020  |2        |0.83
INR |SAR  |01/04/2020  |1        |80
.
.

我正在为一些金额选择我的销售订单表，现在我需要根据销售订单表中的交易日期将交易货币金额转换为欧元、美元和印度卢比。

When transaction currency = the currency under consideration assign the amount accordingly
When transaction currency <> the currency then
    if the relation exists is currency table.
        If the rate is maintaied with Expressinbase = 1 then Amount in <curr> = Sales Order Amount / rate
        If the rate is maintaied with Expressinbase = 2 then Amount in <curr> = Sales Order Amount * rate
    If no direct relation is maintained (for USD or INR)
        Amount in <USD or INR> = Amount in EUR/ rate of EUR to <USD or INR>

这对逻辑很有帮助，但我仍然坚持按交易日期从货币表中仅获取 1 条记录

Implicitly Calculate Exchange Rates in SQL from Exchange Rate table

Answer 1

我不知道您的订单结构是什么，但您应该能够以类似的方式解决它，只需根据您的条件进行调整

IF OBJECT_ID(N'tempdb..#currency', N'U') IS NOT NULL   
DROP TABLE #currency

create table #currency (bcurr VARCHAR(3), curr VARCHAR(3), effectivedt DATETIME, Expressinbase MONEY, rate MONEY)

INSERT INTO #currency VALUES ( 'EUR', 'SAR', '20200401' ,1 ,12.23)
INSERT INTO #currency VALUES ( 'USD', 'SAR', '20200401' ,1 ,45)
INSERT INTO #currency VALUES ( 'INR', 'SAR', '20200401' ,1 ,80)

IF OBJECT_ID(N'tempdb..#orders', N'U') IS NOT NULL   
DROP TABLE #orders

create table #orders (id int IDENTITY(1,1), description VARCHAR(500), price MONEY, currency VARCHAR(3), order_date DATETIME)
INSERT INTO #orders VALUES('first order', 23.4, 'SAR', '20200401')
INSERT INTO #orders VALUES('second order', 15.4, 'SAR', '20200401')
INSERT INTO #orders VALUES('third order', 80.4, 'SAR', '20200401')

;with prices as (select o.id, o.description, o.price, o.currency,
       priceusd = ( CASE WHEN c.bcurr = 'USD' THEN o.price / c.rate else 0 END),
       priceeur = ( CASE WHEN c.bcurr = 'EUR' THEN o.price / c.rate else 0 END),
       princeinr = ( CASE WHEN c.bcurr = 'INR' THEN o.price / c.rate else 0 END)
from #orders o 
inner join #currency c on o.currency = c.curr and o.order_date = c.effectivedt)
select id, description, price, currency, priceusd= SUM(priceusd),  priceeur = SUM(priceeur), priceinr = SUM(princeinr)
from prices 
group by id, description, price, currency