Question

我有一个带有日期列的简单表。我需要获取最大日期，然后今天进行比较，看看它是否早于或晚于getdate（）

以下是我的表现方式。是否有更简洁的方式来表达它？

declare @maxDate datetime
declare @todayDate datetime

with firsttable as (
  select max(ColumnA) as MaxColumnA from tbl
  )
  select @maxDate = MaxColumnA from firsttable
  select @todayDate = GETDATE()
  if (@maxDate > @todayDate)
  begin
    select 'variable date is later than today' 
  end
  else
  begin
    select 'variable date is earlier than today'
  end

See my SQL Fiddle

Answer 1

你不能用＆＃34;如果存在＆＃34;像这样？

if exists (select 1 from tbl where ColumnA > getdate()) begin
   select 'variable date is later than today' 
end else begin
    select 'variable date is earlier than today'
end

Answer 2

FIDDLE DEMO

尝试：

select case when cast(max(date1)  as date)>cast(getdate() as date) 
then 'variable date is later than today' else 'variable date is earlier than 
today' end from tab1

Answer 3

这是另一种选择：

declare @tbl TABLE 
(
    Id INT PRIMARY KEY IDENTITY(1,1)
    ,Date DATETIME
)

INSERT INTO @tbl
(
    Date
)
VALUES ('3/26/2015'),('3/26/2025')

SELECT TOP 1
    CASE 
        WHEN Date > GETDATE() THEN 'variable date is later than today'
        ELSE 'variable date is earlier than today'
    END
FROM 
    @tbl
ORDER BY 
    Date DESC

获取最新日期并立即进行比较

3 个答案: