在SQL中将字符串yyyymmddhhmmss转换为hh：mm：ss格式

Question

With the string DATETIME yyyymmddhhmmss like 20160125173013 , I would like to convert this string into hh:mm:ss (17:30:13) as a new column called "Time" in a table with sql update statement. However I am only able to convert it into 17:30 using the stuff function. Is there any possible solution to convert?

In my statement

UPDATE db
SET Time =convert(time, stuff(substring(DATETIME,9,6),3,2,':'))
FROM db
WHERE Time IS NULL

Real Output= 17:13:00.0000000

But my expected output is 17:13:00

Thanks a lot!

Answer 1

这是mysql的奇迹：

SELECT time(str_to_date('20160125173013', '%Y%m%d%H%i%s'));

Answer 2

If you ar eusing SQL server then use Convert function

 Declare  @VarCharDate  varchar(max)
 Declare  @VarCharDate1 varchar(max)

--Declare

set  @VarCharDate = '20160125173013' --- YYYYMMDDHHMMSS

--Convert

 set @VarCharDate1 =(select SUBSTRING(@VarCharDate,0,5) + '/' +
SUBSTRING(@VarCharDate,5,2)  + '/' + SUBSTRING(@VarCharDate,7,2)
  +  ' ' + SUBSTRING(@VarCharDate,9,2)
  +':'+SUBSTRING(@VarCharDate,11,2) +':' + RIGHT(@VarCharDate,2))

   select @VarCharDate1



 select  Convert(varchar(8),convert(datetime, @VarCharDate1, 120),114)

Answer 3

Do you have an actual DATETIME field? If so you can use DATE_FORMAT() :

UPDATE mytable SET my_time=DATE_FORMAT(my_date, '%H:%i:%s')

If you don't have a native DATETIME field I hope you can convert it to one, as irregular, quirky formats cause trouble and introduce a lot of overhead when parsing to convert. STR_TO_DATE() can do the opposite of DATE_FORMAT() and convert from arbitrary strings to native DATE or DATETIME values.

Answer 4

Don't confuse STORAGE with PRESENTATION

Declare @YourTable table (DateTime varchar(25),Time time)
Insert Into @YourTable values
('20160125173013',null)

Update @YourTable
   Set Time = stuff(left(right(DateTime,6),4),3,0,':')

Select * 
      ,FormatedTime = Format(cast(Time as datetime),'HH:mm')
 From @YourTable

Returns

DateTime        Time                FormatedTime
20160125173013  17:30:00.0000000    17:30

Answer 5

Based on the use of the STUFF function I believe this is Microsoft SQL Server, and not MySql. Therefor, you can do something like this:

UPDATE db
SET [Time] = CAST(SUBSTRING([DATETIME], 9, 2) +':'+ 
                  SUBSTRING([DATETIME], 11, 2) +':'+ 
                  RIGHT([DATETIME], 2) As Time)
WHERE [Time] IS NULL

Answer 6

Your string is no format, SQL Server will cast implicitly

DECLARE @YourDateTimeString VARCHAR(100)='20160125173013';

The following query will cut the first 8 digits and cast them to DATE , which works implicitly (unseparated format). The time is cut from the right side, then the two : -signs are stuffed into the right places:

SELECT CAST(LEFT(@YourDateTimeString,8) AS DATE)
      ,CAST(STUFF(STUFF(RIGHT(@YourDateTimeString,6),5,0,':'),3,0,':') AS TIME);

The result

2016-01-25  17:30:13.0000000

If you need this as string without the trailing .0000000 ( which is a pure output format question and should be done in your presentation layer! ) you can just use LEFT() . The input of this function is string (again implicitly casted), the output is a text which looks like a time .

SELECT CAST(LEFT(@YourDateTimeString,8) AS DATE)
      ,LEFT(CAST(STUFF(STUFF(RIGHT(@YourDateTimeString,6),5,0,':'),3,0,':') AS TIME),8);

The result

2016-01-25  17:30:13