在 SQL 中将日期拆分为 2 列（日期 + 时间）

Question

我正在尝试将表中的数字日期键转换为日期时间键。 我当前的查询是：

  SELECT 
  DATEADD(HOUR,-4,CONVERT(DATETIME,LEFT([Date],8)+' '+
  SUBSTRING([Date],10,2)+':'+
  SUBSTRING([Date],12,2)+':'+
  SUBSTRING([Date],14,2)+'.'+
  SUBSTRING([Date],15,3))) [Date],
  [Object] AS [Dataset],
  SUBSTRING(Parms,1,6) AS [Media]
  FROM (Select CONVERT(VARCHAR(18),[Date]) [Date], 
  [Object],
  MsgId,
  Parms
  FROM JnlDataSection) A
  Where MsgID = '325' AND
  SUBSTRING(Parms,1,6) = 'V40449' 
  Order By Date DESC;

日期栏显示： 2013-06-22 13:36:44.403

我想将其分为两列： 日期： 2013-06-22

时间（去除微秒）： 13:36:44

任何人都可以修改我现有的查询以显示所需的输出吗？我们将不胜感激。 请注意：我使用的是 SQL Server Management Studio 2008。

Answer 1

SELECT CONVERT(DATE,[Date])
SELECT CONVERT(TIME(0),[Date])

Answer 2

您可能想研究一下convert()函数：

  select convert(date, getdate()) as [Date], convert(varchar(8), convert(time, getdate())) as [Time]

给予

  Date       Time
  ---------- --------
  2013-07-16 15:05:43

将这些包裹在原始 SQL 周围会带来不可否认的非常丑陋的结果：

SELECT convert(date, 
      DATEADD(HOUR,-4,CONVERT(DATETIME,LEFT([Date],8)+' '+
        SUBSTRING([Date],10,2)+':'+
        SUBSTRING([Date],12,2)+':'+
        SUBSTRING([Date],14,2)+'.'+
        SUBSTRING([Date],15,3)))) [Date],
  convert(varchar(8), convert(time, 
      DATEADD(HOUR,-4,CONVERT(DATETIME,LEFT([Date],8)+' '+
        SUBSTRING([Date],10,2)+':'+
        SUBSTRING([Date],12,2)+':'+
        SUBSTRING([Date],14,2)+'.'+
        SUBSTRING([Date],15,3))))) [Time],

  [Object] AS [Dataset],
  SUBSTRING(Parms,1,6) AS [Media]
  FROM (Select CONVERT(VARCHAR(18),[Date]) [Date], 
  [Object],
  MsgId,
  Parms
  FROM JnlDataSection) A
  Where MsgID = '325' AND
  SUBSTRING(Parms,1,6) = 'V40449' 
  Order By Date DESC;

您可能想将其中的一部分移至视图中，只是为了降低复杂性。

Answer 3

您可以使用STUFF功能:

DECLARE @MyTable TABLE([Date] VARCHAR(20));
INSERT  @MyTable ([Date])
VALUES  ('20130622133644403');

SELECT  y.*,
        CONVERT(DATE,y.Date_AsDateTime) AS OnlyDate,
        CONVERT(TIME(0),y.Date_AsDateTime) AS OnlyTime
FROM(
    SELECT  x.[Date] AS Date_AsVarChar, CONVERT(DATETIME, STUFF(STUFF(STUFF(STUFF(x.[Date],9,0,' '),12,0,':'),15,0,':'),18,0,'.')) AS Date_AsDateTime
    FROM    @MyTable x
) y;

结果：

Date_AsVarChar       Date_AsDateTime         OnlyDate   OnlyTime
-------------------- ----------------------- ---------- --------
20130622133644403    2013-06-22 13:36:44.403 2013-06-22 13:36:44

解决方案：

SELECT 
    CONVERT(DATE,y.Date_AsDateTime) AS OnlyDate,
    CONVERT(TIME(0),y.Date_AsDateTime) AS OnlyTime
FROM(
    SELECT [Object], MsgId, Parms,
        CONVERT(DATETIME, STUFF(STUFF(STUFF(STUFF(x.[Date],9,0,' '),12,0,':'),15,0,':'),18,0,'.')) AS Date_AsDateTime
    FROM JnlDataSection
) A
WHERE   MsgID = '325' 
-- SUBSTRING(Parms,1,6) = 'V40449' is not SARG-able
AND     Parms LIKE 'V40449%' 
ORDER BY DATE DESC;

Answer 4

使用以下场景获取日期、时间、日、月、年、时、分、秒、AM/PM：

select 
   UpdatedOn , CONVERT(varchar,UpdatedOn,100) DateTime, CONVERT(varchar,UpdatedOn,10) Date , 
   CONVERT(varchar,UpdatedOn,108) Time , substring(CONVERT(varchar,UpdatedOn,106),1,2) Day, 
   substring(CONVERT(varchar,UpdatedOn,106),4,3) CMonth,    
   substring(CONVERT(varchar,UpdatedOn,105),4,2) 
   NMonth, substring(CONVERT(varchar,UpdatedOn,106),8,4) Year,      
   left(right(CONVERT(varchar,UpdatedOn,100),7),2) Hours_12, 
   substring(CONVERT(varchar,UpdatedOn,108),1,2) Hours_24, 
   substring(CONVERT(varchar,UpdatedOn,108),4,2) Minutes, 
   substring(CONVERT(varchar,UpdatedOn,108),7,2) Second, right(CONVERT(varchar,UpdatedOn,100),2)    
   AM_PM 
from 
   dbo.DeviceAssignSim where AssignSimId=55;

Answer 5

今天最简单的方法是：

SELECT 
    CAST(OrderDate AS DATE) AS OrderDateOnly, -- Extracts the date part
    CAST(OrderDate AS TIME) AS OrderTimeOnly  -- Extracts the time part
FROM 
    Orders;