返回过去 3 个预约和接下来 3 个预约

Question

我需要获取某个日期过去 3 个预约和接下来 3 个预约。每个查询都会给出预期的结果。我的问题是我需要一起得到结果。我无法使用 UNION，因为我需要在两个查询中使用 ORDER BY。我怎样才能做到这一点？

--This is for the future appointments
SELECT TOP 3 
    e.Events, e.EventDate
FROM
    events e
JOIN 
    EventMatters em ON em.Events = e.Events
WHERE 
    Matters = '000122FD-47B6-47B6-47B6-1FCAB474CE53' 
    AND EventKind = 'D' 
    AND CONVERT(DATE, e.eventdate) > '2022/05/03'
ORDER BY 
    e.EventDate

--This is for the past appointments
SELECT TOP 3 
    e.Events, e.EventDate
FROM
    events e
JOIN 
    EventMatters em ON em.Events = e.Events
WHERE 
    Matters = '000122FD-47B6-47B6-47B6-1FCAB474CE53' 
    AND e.EventKind = 'D' 
    AND CONVERT(DATE, e.eventdate) < '2022/05/03'
ORDER BY 
    EventDate DESC

Answer 1

你可以做两个

CTE

和

UNION ALL

他们

--This is for the future appointments
WITH CTE_AFTER AS(SELECT TOP 3 
    e.Events, e.EventDate
FROM
    events e
JOIN 
    EventMatters em ON em.Events = e.Events
WHERE 
    Matters = '000122FD-47B6-47B6-47B6-1FCAB474CE53' 
    AND EventKind = 'D' 
    AND CONVERT(DATE, e.eventdate) > '2022/05/03'
ORDER BY 
    e.EventDate),  
CTE_BEFORE AS(

SELECT TOP 3 
    e.Events, e.EventDate
FROM
    events e
JOIN 
    EventMatters em ON em.Events = e.Events
WHERE 
    Matters = '000122FD-47B6-47B6-47B6-1FCAB474CE53' 
    AND e.EventKind = 'D' 
    AND CONVERT(DATE, e.eventdate) < '2022/05/03'
ORDER BY 
    EventDate DESC)
    SELECT Events, EventDate FROM CTE_AFTER
    UNION ALL 
    SELECT Events, EventDate FROM CTE_BEFORE

Answer 2

如果您不关心最终订单：

  SELECT * FROM
  (
    SELECT TOP (3) ... FROM ... WHERE ... ORDER BY EventDate
  ) x
  UNION ALL
  SELECT * FROM
  (
    SELECT TOP (3) ... FROM ... WHERE ... ORDER BY EventDate DESC
  ) AS x;

如果您希望按日期排序，最早的在前：

  ) AS x ORDER BY EventDate;

如果您希望最旧的 3 个按最旧的在前排序，而最新的 3 个按最新的在前排序，则情况会变得有点复杂，但仍然可行。