如何从以下 SQL 查询中仅返回 yyyy-mm-dd [重复]

Posted 2023-03-29

【中文标题】如何从以下 SQL 查询中仅返回 yyyy-mm-dd [重复]

【英文标题】：How to return just the yyyy-mm-dd from the following SQL queries [duplicate]

【发布时间】：2018-07-03 20:15:36

【问题描述】：

以下是我创建的查询。查询#1 返回2018-07-06 00:00:00.000，查询#2 返回2018-07-31 23:59:59.997。

我不知道如何修改查询，以便它们以yyyy-mm-dd 格式返回结果。请指教。

查询 #1 - 获取每月的第五个工作日

SELECT 
    FifthWeekDay = DATEADD(dd, CASE 
                                  WHEN DATEDIFF(dd, -1, ca.FirstOfMonth) % 7 > 1 -- -1 is a Sunday
                                     THEN 7 
                                     ELSE 6 - DATEDIFF(dd, -1, ca.FirstOfMonth) % 7 -- -1 is a Sunday
                               END, ca.FirstOfMonth - 1)
FROM 
    (SELECT 
         DATEADD(mm, (SELECT DATEPART(YEAR, GETDATE())) * 12 - 22801 +
                     (SELECT DATEPART(M, GETDATE())), 0)) ca(FirstOfMonth)

查询 #2 - 获取本月的最后一个工作日

SELECT 
    DATEADD(ms, -3, DATEADD(mm, DATEDIFF(mm, 0, GETDATE()) + 1, 0))
    - CASE DATENAME(dw, DATEADD(ms, -3, DATEADD(mm, DATEDIFF(mm, 0, GETDATE()) + 1, 0)))
         WHEN 'SUNDAY' THEN 2
         WHEN 'SATURDAY' THEN 1
         ELSE 0
      END AS LastBusinessCurrentMonth

【问题讨论】：

您使用的是哪个 dbms？ （这些查询是特定于产品的。）

jarlh- 我正在使用 SQL Server 2014

【参考方案1】：

您可以对已有的结果进行子查询并添加演员表（作为日期）：

SELECT CAST(LastBusinessCurrentMonth AS DATE) AS LastBusinessCurrentMonth FROM(
SELECT 
    DATEADD(ms, -3, DATEADD(mm, DATEDIFF(mm, 0, GETDATE()) + 1, 0))
    - CASE DATENAME(dw, DATEADD(ms, -3, DATEADD(mm, DATEDIFF(mm, 0, GETDATE()) + 1, 0)))
         WHEN 'SUNDAY' THEN 2
         WHEN 'SATURDAY' THEN 1
         ELSE 0
      END AS LastBusinessCurrentMonth) AS X

SELECT CAST(FIFTHWEEKDAY AS DATE) AS FIFTHWEEKDAY FROM(
SELECT 
    FifthWeekDay = DATEADD(dd, CASE 
                                  WHEN DATEDIFF(dd, -1, ca.FirstOfMonth) % 7 > 1 -- -1 is a Sunday
                                     THEN 7 
                                     ELSE 6 - DATEDIFF(dd, -1, ca.FirstOfMonth) % 7 -- -1 is a Sunday
                               END, ca.FirstOfMonth - 1)
FROM 
    (SELECT 
         DATEADD(mm, (SELECT DATEPART(YEAR, GETDATE())) * 12 - 22801 +
                     (SELECT DATEPART(M, GETDATE())), 0)) ca(FirstOfMonth)) AS X

或者您可以将变量声明为 Date 并将查询结果设置为该变量：

DECLARE @DATEVAR DATE

SET @DATEVAR =(
SELECT 
    DATEADD(ms, -3, DATEADD(mm, DATEDIFF(mm, 0, GETDATE()) + 1, 0))
    - CASE DATENAME(dw, DATEADD(ms, -3, DATEADD(mm, DATEDIFF(mm, 0, GETDATE()) + 1, 0)))
         WHEN 'SUNDAY' THEN 2
         WHEN 'SATURDAY' THEN 1
         ELSE 0
      END AS LastBusinessCurrentMonth)

SELECT @DATEVAR AS LastBusinessCurrentMonth

SET @DATEVAR = (SELECT 
    DATEADD(ms, -3, DATEADD(mm, DATEDIFF(mm, 0, GETDATE()) + 1, 0))
    - CASE DATENAME(dw, DATEADD(ms, -3, DATEADD(mm, DATEDIFF(mm, 0, GETDATE()) + 1, 0)))
         WHEN 'SUNDAY' THEN 2
         WHEN 'SATURDAY' THEN 1
         ELSE 0
      END AS LastBusinessCurrentMonth)

SELECT @DATEVAR AS LastBusinessCurrentMonth