如何从SQL Server的数据范围中选择上一个和下一个数据？

Question

我想从范围月份中选择数据。 示例： @month = 4然后是从15-03到15-05数据。 它看起来工作正常。

Wood    25-03-1990
Mary    10-04-1988
Brown   25-04-1989
White   10-05-1992

但是，当我尝试@month = 1或@month = 12 ，找不到数据。 这是数据和代码片段

NAME    BIRTHDAY
John    10-11-1988
Green   25-11-1990
Black   25-12-1989
Blue    10-12-1991
Red     10-01-1992
Candy   25-01-1989
Food    10-02-1993
Apple   25-02-1988
Wood    25-03-1990
Meat    10-03-1991
Mary    10-04-1988
Brown   25-04-1989
White   10-05-1992
Yellow  25-05-1993

和 SQL-T

SELECT * FROM ABC
WHERE 
    CONVERT(DATE,CONVERT(VARCHAR(2),DATEPART(DAY,CONVERT(DATE,BIRTHDAY,105)))+'-'+
    CONVERT(VARCHAR(2), DATEPART(MONTH,CONVERT(DATE,BIRTHDAY,105)))+'-'+
    CONVERT(VARCHAR(4),YEAR(GETDATE())),105) 
BETWEEN 

    CONVERT(DATE,'15'+'-'+CONVERT(VARCHAR(2),
    --CASE 
    --     WHEN @month = 1 THEN '12' 
    --     WHEN @month = 12 THEN '11' 
    --     WHEN @month <> 1 AND @month <> 12 THEN @month-1
    --END 
    @month-1
    )+'-'+CONVERT(VARCHAR(4),YEAR(GETDATE())),105)
AND
    CONVERT(DATE,'15'+'-'+CONVERT(VARCHAR(2),
    --CASE 
    --     WHEN @month = 1 THEN '2' 
    --     WHEN @month = 12 THEN '1' 
    --     WHEN @month <> 1 AND @month <> 12 THEN @month+1
    --END
    @month+1
    )+'-'+CONVERT(VARCHAR(4),YEAR(GETDATE())),105)

Answer 1

将列作为日期时间会使事情变得更容易，但是如何：

declare @Month int
SELECT @Month =1
-- Get start of the period
declare @baseDate date
SELECT @baseDate = CONVERT(DATE,'15-'+CONVERT(char(2), @Month)+'-'+convert(varchar(4),YEAR(GETDATE())), 105)
Print @baseDate
declare @startDate date
SELECT @startDate = DATEADD(mm,-1, @baseDate)
PRINT @startDate
declare @endDate date
SELECT @endDate = DATEADD(mm,+1, @baseDate)
PRINT @endDate

SELECT *,DATEADD(yy, YEAR(GETDATE())-YEAR(CONVERT(datetime, birthday, 105)),CONVERT(date, birthday, 105)) FROM ABC
WHERE 
DATEADD(yy, YEAR(@StartDate)-YEAR(CONVERT(datetime, birthday, 105)),CONVERT(date, birthday, 105))
BETWEEN 
@StartDate AND @EndDate
OR
DATEADD(yy, YEAR(@EndDate)-YEAR(CONVERT(datetime, birthday, 105)),CONVERT(date, birthday, 105))
BETWEEN 
@StartDate AND @EndDate

** 根据 OP 的错误报告，在将生日调整为当前年份时进行了编辑以纠正错误