Question

我有一张名为Orders的表格。它有id，orderid，qty，cost，location，currency ......等列。

我必须将此订单表中的值插入到给定order id的另一个表中，但问题出在currency。

对于每个orderid，order表格中会有多行，每行可能有差异currency。

因此，当从此表中为orderid插入新行时，我需要计算不同的货币并插入具有最高计数的货币。

如何比较列中不同值的计数？这是在SQL Server中。

Answer 1

with cte as
(
select orderid,currency, row_number() over
    (partition by orderid,currency order by orderid,currency) rownumber
  from orders 
)  

select cte.orderid,cte.currency 
from cte
join
(select orderid,max(rownumber) rownumber2
  from cte group by orderid) A
on cte.orderid=a.orderid and cte.rownumber=a.rownumber2

演示SQLFIDDLE：http://sqlfiddle.com/#!3/1c046/25

感谢bluefeet提供样本数据

Answer 2

您的要求并不十分清楚，但您似乎可以使用以下内容：

select o.id,
  o.orderid,
  o.currency,
  o.cost
from orders o
inner join
(
  select orderid, currency,
    CountCurrency,
    max(CountCurrency) over(partition by orderid) mx
  from
  (
    select orderid, currency, count(currency) CountCurrency
    from orders
    group by orderid, currency
  ) o
) m
  on o.orderid = m.orderid
  and o.currency = m.currency
where m.CountCurrency = m.mx
order by o.orderid, o.id

请参阅SQL Fiddle with Demo

这将返回包含orderid最常出现的货币的所有行。使用样本数据：

CREATE TABLE orders
    ([id] int, [orderid] int, [currency] varchar(3), [cost] int)
;

INSERT INTO orders
    ([id], [orderid], [currency], [cost])
VALUES
    (1, 10, 'USD', 1000),
    (2, 10, 'EUR', 522),
    (3, 10, 'USD', 999),
    (4, 10, 'INR', 999),
    (5, 20, 'TST', 557),
    (6, 25, 'GRB', 24),
    (7, 20, 'TST', 78),
    (8, 30, 'HYT', 3)
;

结果是：

| ID | ORDERID | CURRENCY | COST |
----------------------------------
|  1 |      10 |      USD | 1000 |
|  3 |      10 |      USD |  999 |
|  5 |      20 |      TST |  557 |
|  7 |      20 |      TST |   78 |
|  6 |      25 |      GRB |   24 |
|  8 |      30 |      HYT |    3 |

Answer 3

如果我正确理解了您的问题，那么您正在尝试在Orders表中找到具有最多记录的货币，并给出具体的OrderId？

这样的事情 - 如果多个货币用相同的计数表示，它可以返回多个记录吗？

SELECT MAX(c.CurrencyCount), c.currency
FROM 
(
    SELECT currency, Count(currency) as CurrencyCount
    FROM Orders
    WHERE OrderId = 12345
    GROUP BY currency
) c
GROUP BY c.currency

Answer 4

据我所知，您是否希望将行从Orders迁移到otherTable，包括另外两列：maxCurrency和totalDistinctCurrency。

如果我的理解是正确的，那么你可以这样做：

INSERT INTO otherTable(
  maxCurrency, 
  totalDistinctCurrency, 
  otherColsFromOrders) 
SELECT 
  MAX(currency), 
  COUNT(DISTINCT currency), 
  * 
FROM Orders  
WHERE orderid = SOME_ORDER_ID_YOU_WANT;

注意两点：

您可以通过所需的 orderid 更改SOME_ORDER_ID_YOU_WANT;
您可以将 otherColsFromOrders 更改为otherTable中相应列的名称，这些列将与Orders表中列的顺序相匹配，因为选择时为*。

希望它有所帮助！

Answer 5

还有一个选项

SELECT *
FROM Orders t
WHERE EXISTS(
             SELECT CASE WHEN MAX(COUNT(t2.currency)) OVER() = COUNT(t2.currency) THEN t2.currency END
             FROM Orders t2             
             WHERE t2.orderid = t.orderid            
             GROUP BY t2.currency
             INTERSECT
             SELECT t.currency
             )

SQLFiddle上的演示

比较表中的列值计数

5 个答案: