我有一个表，上面列出了人们的出生日期(目前是nvarchar(25))
我如何将其转换为日期，然后以年为单位计算他们的年龄?
我的数据如下所示
ID Name DOB
1 John 1992-01-09 00:00:00
2 Sally 1959-05-20 00:00:00
我希望看到:
ID Name AGE DOB
1 John 17 1992-01-09 00:00:00
2 Sally 50 1959-05-20 00:00:00
当前回答
DECLARE @FromDate DATETIME = '1992-01-2623:59:59.000',
@ToDate DATETIME = '2016-08-10 00:00:00.000',
@Years INT, @Months INT, @Days INT, @tmpFromDate DATETIME
SET @Years = DATEDIFF(YEAR, @FromDate, @ToDate)
- (CASE WHEN DATEADD(YEAR, DATEDIFF(YEAR, @FromDate, @ToDate),
@FromDate) > @ToDate THEN 1 ELSE 0 END)
SET @tmpFromDate = DATEADD(YEAR, @Years , @FromDate)
SET @Months = DATEDIFF(MONTH, @tmpFromDate, @ToDate)
- (CASE WHEN DATEADD(MONTH,DATEDIFF(MONTH, @tmpFromDate, @ToDate),
@tmpFromDate) > @ToDate THEN 1 ELSE 0 END)
SET @tmpFromDate = DATEADD(MONTH, @Months , @tmpFromDate)
SET @Days = DATEDIFF(DAY, @tmpFromDate, @ToDate)
- (CASE WHEN DATEADD(DAY, DATEDIFF(DAY, @tmpFromDate, @ToDate),
@tmpFromDate) > @ToDate THEN 1 ELSE 0 END)
SELECT @FromDate FromDate, @ToDate ToDate,
@Years Years, @Months Months, @Days Days
其他回答
闰年/日和以下方法有问题，请参阅下面的更新:
try this: DECLARE @dob datetime SET @dob='1992-01-09 00:00:00' SELECT DATEDIFF(hour,@dob,GETDATE())/8766.0 AS AgeYearsDecimal ,CONVERT(int,ROUND(DATEDIFF(hour,@dob,GETDATE())/8766.0,0)) AS AgeYearsIntRound ,DATEDIFF(hour,@dob,GETDATE())/8766 AS AgeYearsIntTrunc OUTPUT: AgeYearsDecimal AgeYearsIntRound AgeYearsIntTrunc --------------------------------------- ---------------- ---------------- 17.767054 18 17 (1 row(s) affected)
以下是一些更准确的方法:
多年来最好的方法
DECLARE @Now datetime, @Dob datetime
SELECT @Now='1990-05-05', @Dob='1980-05-05' --results in 10
--SELECT @Now='1990-05-04', @Dob='1980-05-05' --results in 9
--SELECT @Now='1989-05-06', @Dob='1980-05-05' --results in 9
--SELECT @Now='1990-05-06', @Dob='1980-05-05' --results in 10
--SELECT @Now='1990-12-06', @Dob='1980-05-05' --results in 10
--SELECT @Now='1991-05-04', @Dob='1980-05-05' --results in 10
SELECT
(CONVERT(int,CONVERT(char(8),@Now,112))-CONVERT(char(8),@Dob,112))/10000 AS AgeIntYears
您可以将上面的10000更改为10000.0并获得小数，但它不会像下面的方法那样准确。
用十进制表示年份的最佳方法
DECLARE @Now datetime, @Dob datetime
SELECT @Now='1990-05-05', @Dob='1980-05-05' --results in 10.000000000000
--SELECT @Now='1990-05-04', @Dob='1980-05-05' --results in 9.997260273973
--SELECT @Now='1989-05-06', @Dob='1980-05-05' --results in 9.002739726027
--SELECT @Now='1990-05-06', @Dob='1980-05-05' --results in 10.002739726027
--SELECT @Now='1990-12-06', @Dob='1980-05-05' --results in 10.589041095890
--SELECT @Now='1991-05-04', @Dob='1980-05-05' --results in 10.997260273973
SELECT 1.0* DateDiff(yy,@Dob,@Now)
+CASE
WHEN @Now >= DATEFROMPARTS(DATEPART(yyyy,@Now),DATEPART(m,@Dob),DATEPART(d,@Dob)) THEN --birthday has happened for the @now year, so add some portion onto the year difference
( 1.0 --force automatic conversions from int to decimal
* DATEDIFF(day,DATEFROMPARTS(DATEPART(yyyy,@Now),DATEPART(m,@Dob),DATEPART(d,@Dob)),@Now) --number of days difference between the @Now year birthday and the @Now day
/ DATEDIFF(day,DATEFROMPARTS(DATEPART(yyyy,@Now),1,1),DATEFROMPARTS(DATEPART(yyyy,@Now)+1,1,1)) --number of days in the @Now year
)
ELSE --birthday has not been reached for the last year, so remove some portion of the year difference
-1 --remove this fractional difference onto the age
* ( -1.0 --force automatic conversions from int to decimal
* DATEDIFF(day,DATEFROMPARTS(DATEPART(yyyy,@Now),DATEPART(m,@Dob),DATEPART(d,@Dob)),@Now) --number of days difference between the @Now year birthday and the @Now day
/ DATEDIFF(day,DATEFROMPARTS(DATEPART(yyyy,@Now),1,1),DATEFROMPARTS(DATEPART(yyyy,@Now)+1,1,1)) --number of days in the @Now year
)
END AS AgeYearsDecimal
因为没有一个简单的答案总是能给出正确的年龄，下面是我想到的。
SELECT DATEDIFF(YY, DateOfBirth, GETDATE()) -
CASE WHEN RIGHT(CONVERT(VARCHAR(6), GETDATE(), 12), 4) >=
RIGHT(CONVERT(VARCHAR(6), DateOfBirth, 12), 4)
THEN 0 ELSE 1 END AS AGE
这将获得出生日期和当前日期之间的年差。如果出生日期还没过，就减去一年。
任何时候都是准确的——不管闰年或离生日有多近。
最棒的是——没有功能。
这个怎么样:
SET @Age = CAST(DATEDIFF(Year, @DOB, @Stamp) as int)
IF (CAST(DATEDIFF(DAY, DATEADD(Year, @Age, @DOB), @Stamp) as int) < 0)
SET @Age = @Age - 1
SELECT ID,
Name,
DATEDIFF(yy,CONVERT(DATETIME, DOB),GETDATE()) AS AGE,
DOB
FROM MyTable
select datediff(day,'1991-03-16',getdate()) \\for days,get date refers today date
select datediff(year,'1991-03-16',getdate()) \\for years
select datediff(month,'1991-03-16',getdate()) \\for month
