Question

我有小桌子

Create Table TestDates
(
  TestDateId int identity (1,1),
  RunDateTime DateTime
)

我会在表格中插入一些值

Insert into TestDates
(RunDateTime)
Values
(getdate())

Insert into TestDates
(RunDateTime)
Values
( DATEADD(DAY,  -1, GETDATE()))

Insert into TestDates
(RunDateTime)
Values
( DATEADD(DAY,  -2, GETDATE()))

Insert into TestDates
(RunDateTime)
Values
( DATEADD(DAY,  -3, GETDATE()))

Insert into TestDates
(RunDateTime)
Values
( DATEADD(Hour,  -34, GETDATE()))

Insert into TestDates
(RunDateTime)
Values
( DATEADD(Hour,  -12, GETDATE()))

我设法执行不同的查询，只给我带来时间

SELECT DISTINCT 
DATENAME(hour, RunDateTime) + ':' + 
DATENAME(mi, RunDateTime) AS  DistinctDate
from TestDates

但我需要指出今天或昨天出现的时间

例如

DistinctDate   IsToday   IsYesterday

10:33           N          Y
20:31           Y          N
8:33            N          N

请帮忙

Answer 1

可以使用带有约会的案例陈述。

SELECT DISTINCT 
DATENAME(hour, RunDateTime) + ':' + 
DATENAME(mi, RunDateTime) AS  DistinctDate,
CASE WHEN DATEDIFF(day, RunDateTime, GETDATE()) = 0 THEN 'Y' ELSE 'N' END IsToday,
CASE WHEN DATEDIFF(day, RunDateTime, GETDATE()) = 1 THEN 'Y' ELSE 'N' END IsYesterday
from TestDates

Answer 2

确定日期是今天还是昨天的一种方法是：

SELECT DISTINCT  
       DATENAME(hour, RunDateTime) + ':' + DATENAME(mi, RunDateTime) AS  DistinctDate,
       CASE WHEN DATEPART(day,RunDateTime) = DATEPART(day,GetDate()) THEN 1 
       ELSE 0 END as IsToday 
  FROM TestDates

另一种方法是：

SELECT DISTINCT  
       DATENAME(hour, RunDateTime) + ':' + DATENAME(mi, RunDateTime) AS  DistinctDate,
       CASE WHEN DATEDIFF(day,RunDateTime,getdate()) = 0 THEN 1 
       ELSE 0 END as IsToday
  FROM TestDates

IsToday列将在今天显示昨天的其他时间。当你只需要在两者之间进行识别时，这就会产生影响。

基于您的示例的最终结果是：

DistinctDate   IsToday

10:33           0
20:31           1
8:33            0

SQL Server DateTime指示今天和昨天

2 个答案: