两个条件都满足时双记录 SQL

Question

我的表中有一条记录：

我需要的是创建一个带有订单状态的列：“1”表示订单已创建，“0”表示订单已取消。

所以对于这个例子，当有创建和取消时，我需要两个状态。决赛桌应该是：

我该怎么做？

Answer 1

我认为你可以简单地做一个这样的联合：

select OrderCreateDate, OrderCancelDate, ReportDate, 1 as OrderState
  from your_table
  where orderCreateDate is not null
union all
select OrderCreateDate, OrderCancelDate, ReportDate, 0 as OrderState
  from your_table
  where orderCancelDate is not null

Answer 2

这样做的一种方法是多次加入您的表，并在连接上施加约束以限制您的结果集；这是一种简单的数据透视方法，但会影响性能。

DECLARE @a TABLE (id INT, createdate date,canceldate date,reportdate DATE)

INSERT INTO @a (id, createdate, canceldate, reportdate)
VALUES (
    1, -- id - int
    GETDATE(), -- createdate - date
    GETDATE(), -- canceldate - date
    GETDATE() -- reportdate - date
)

INSERT INTO @a (id, createdate, canceldate, reportdate)
VALUES (
    2, -- id - int
    GETDATE(), -- createdate - date
    null, -- canceldate - date
    GETDATE() -- reportdate - date
)

SELECT a.id,a.createdate,a.canceldate,a.reportdate,CASE WHEN a1.id IS NOT NULL THEN '1' ELSE 0 END AS 'createdInd'
,CASE WHEN a2.id IS NOT NULL THEN '1' ELSE 0 END AS 'CancelledInd'

FROM @a a 
LEFT  JOIN @a a1 ON a.id = a1.id AND a1.createdate IS NOT NULL
LEFT JOIN @a a2 ON a.id = a2.id AND a2.canceldate IS NOT NULL 


id  createdate  canceldate  reportdate  createdInd  CancelledInd
1   2021-04-07  2021-04-07  2021-04-07  1   1
2   2021-04-07  NULL    2021-04-07  1   0

Answer 3

将返回值 1 和 0 的查询加入表：

SELECT t.*, s.OrderState
FROM tablename AS t
INNER JOIN (SELECT 1 AS OrderState UNION ALL SELECT 0) AS s
ON (s.OrderState = 1 AND t.OrderCreateDate IS NOT NULL)
OR (s.OrderState = 0 AND t.OrderCancelDate IS NOT NULL)