Sql Datetime convert - sql

Question

In a database table, I have two column storing date and time in this format:
D30DAT D30TIM
140224 75700
I need update a new field where store date in the format
2014-02-24 07:57:00.000
How I can use a SQL query to do it?

Answer 1

For Postgres and Oracle (assuming those columns are varchar):
select to_timestamp(dt, 'yymmdd hh24miss')
from (
select d30dat||' '||case when length(d30tim) = 5 then '0'||d30tim else d30tim end as dt
from x
) t;
The case expression adds a leading 0 if the time part only consists of 5 digits so that the format mask can be specified with always 2 digits for the hour. The blank between the two columns is essentially only a debugging aid and could be left out.
The result is a real timestamp value that can easily be formatted using to_char() to the desired format.
SQLFiddle for Postgres: http://sqlfiddle.com/#!15/ac07a/2
SQLFiddle for Oracle: http://sqlfiddle.com/#!4/ac07a2/4

Answer 2

Try this function. Its not particularly fast or great, but converts the fields you specified.
CREATE FUNCTION GetDateTimeFromINT
(
#Date INT,
#Time INT
)
RETURNS DATETIME
AS
BEGIN
DECLARE #YearNo VARCHAR(4)
DECLARE #MonthNo VARCHAR(3)
DECLARE #DayNo VARCHAR(2)
DECLARE #HourNo VARCHAR(2)
DECLARE #MinNo VARCHAR(2)
DECLARE #SecNo VARCHAR(2)
SET #YearNo = LEFT(CONVERT(VARCHAR,#Date), LEN(#Date)-4)
SET #MonthNo = SUBSTRING(CONVERT(VARCHAR,#Date),LEN(#Date)-3,2)
SET #DayNo = SUBSTRING(CONVERT(VARCHAR,#Date),LEN(#Date)-1,2)
SET #HourNo = LEFT(CONVERT(VARCHAR,#Time), LEN(#Time)-4)
SET #MinNo = SUBSTRING(CONVERT(VARCHAR,#Time),LEN(#Time)-3,2)
SET #SecNo = SUBSTRING(CONVERT(VARCHAR,#Time),LEN(#Time)-1,2)
SET #YearNo = '20' + #YearNo
IF LEN(#HourNo) = 1
BEGIN
SET #HourNo = '0' + #HourNo
END
SET #MonthNo = CASE
WHEN #MonthNo = '01' THEN 'JAN'
WHEN #MonthNo = '02' THEN 'FEB'
WHEN #MonthNo = '03' THEN 'MAR'
WHEN #MonthNo = '04' THEN 'APR'
WHEN #MonthNo = '05' THEN 'MAY'
WHEN #MonthNo = '06' THEN 'JUN'
WHEN #MonthNo = '07' THEN 'JUL'
WHEN #MonthNo = '08' THEN 'AUG'
WHEN #MonthNo = '09' THEN 'SEP'
WHEN #MonthNo = '10' THEN 'OCT'
WHEN #MonthNo = '11' THEN 'NOV'
WHEN #MonthNo = '12' THEN 'DEC'
END
RETURN CONVERT(DATETIME, #DayNo + '-' + #MonthNo + '-' + #YearNo +' ' + #HourNo + ':' + #MinNo + ':' + #SecNo)
END
GO
Call it like so:
SELECT *, dbo.GetDateTimeFromINT(D30DAT,T30DAT) OutputDT
FROM SourceTable
If you need help with the update statement, let me know

Answer 3

Because someone gave a convoluted answer in SQL Server, I want to point out that there is a much simpler way.
I also want to point out that the format is not unreasonable. It provides easy access to the date parts and it is sortable. Of course, a real date/time value has these properties as well; I am guessing that this is some legacy format from some ancient system.
In any case, try this:
with t as (select 140224 as ymd, 75700 as hms)
select cast(cast(ymd as varchar(255)) + ' ' +
stuff(stuff(right('000000' + cast(hms as varchar(255)), 6
), 3, 0, ':'
), 6, 0, ':')
from t;
This turns the numbers into the format YYMMDD HH:MM:SS which SQL Server recognizes as a date/time value. Actually it would be better to pre-pend "20" for the four-digit year, but I'm not sure what the OP wants in terms of Y2K convertibility.
Although the code would look a bit different, similar logic would work in most databases.