Combine DATETIME column with CHAR field to create DATETIME2 column - tsql

Question

I am trying to import data from a vendor's database and combine two columns into one for our database. They have two columns are CITATION_DATE which is a datetime data type and CITATION_TIME which is a char(8) data type.
I would like to combine these two columns into one column issueDate which is of datetime2(7) data type.
I tried using Aaron's logic found here but I have not been successful in getting the query to execute. My suspicion is that I need more characters in the CITATION_TIME to form a valid time stamp but I am not sure.
Is there a way to combine these two fields into a single column - that follows the datetime2 format?
My attempt was to try and clean up bad values like empty strings or non-numeric characters:
;WITH issueDate AS
(
SELECT
TRY_CAST(vt.CITATION_DATE AS DATE) AS CITATION_DATE ,
CASE WHEN RTRIM ( LTRIM ( vt.CITATION_TIME )) = '' THEN '0000'
WHEN RTRIM ( LTRIM ( vt.CITATION_TIME )) = '000' THEN '0000'
WHEN TRY_CAST(vt.CITATION_TIME AS INT) IS NULL THEN '0000'
ELSE vt.CITATION_TIME
END AS CITATION_TIME
FROM
Oklahoma_PVD_WildlifeLaw.dbo.VIOLATOR_TICKETS AS vt
--ORDER BY CITATION_TIME;
)
SELECT
CONVERT(DATETIME, CONVERT(CHAR(8), id.CITATION_DATE, 112) + ' ' +
CONVERT(CHAR(8), id.CITATION_TIME, 108))
FROM
issueDate AS id;
But I am getting the following error:
The conversion of a varchar data type to a datetime data type resulted in an out-of-range value
It does look like I do not have enough characters for the TIME portion - as this return values in a DATETIME format, but I lose all of my hours and minutes this way:
;WITH issueDate AS
(
SELECT
TRY_CAST(vt.CITATION_DATE AS DATE) AS CITATION_DATE,
CASE
WHEN RTRIM(LTRIM(vt.CITATION_TIME)) = '' THEN '00:00:00.0000000'
WHEN RTRIM(LTRIM(vt.CITATION_TIME)) = '000' THEN '00:00:00.0000000'
WHEN TRY_CAST(vt.CITATION_TIME AS INT) IS NULL THEN '00:00:00.0000000'
--ELSE vt.CITATION_TIME
END AS CITATION_TIME
FROM
Oklahoma_PVD_WildlifeLaw.dbo.VIOLATOR_TICKETS AS vt
--ORDER BY CITATION_TIME;
)
SELECT
CONVERT(DATETIME, CONVERT(CHAR(8), id.CITATION_DATE, 112) + ' ' +
CONVERT(CHAR(8), id.CITATION_TIME, 108)) AS [DateTime]
FROM
issueDate AS id
WHERE
CONVERT(DATETIME, CONVERT(CHAR(8), id.CITATION_DATE, 112) + ' ' +
CONVERT(CHAR(8), id.CITATION_TIME, 108)) IS NOT NULL;

Answer 1

Did you tried to calculate number of minutes from the time part and add them to the date using DATEADD?
select DATEADD(minute, cast(CITATION_TIME as int) % 100 + 60 * (cast(CITATION_TIME as int) / 100), CITATION_DATE)
FROM Oklahoma_PVD_WildlifeLaw.dbo.VIOLATOR_TICKETS AS vt
This code assumes all dates has zero time part (midnight) and CITATION_TIME are all digits. The code above tries to handle these by casting the datetime to date (to get rid of the time part) and using try_cast to handle non-numeric times. If you need, you can use the same code:
select DATEADD(minute, t.IntTime % 100 + 60 * (t.IntTime / 100), cast(CITATION_DATE as date))
FROM Oklahoma_PVD_WildlifeLaw.dbo.VIOLATOR_TICKETS AS vt
cross apply (select isnull(try_cast(CITATION_TIME as int), 0) as IntTime ) t
If there is invalid "times" in your data, you must decide how to handle them. Try to find these records by searching for values, where last 2 digits are >= 60 for example:
select * from Oklahoma_PVD_WildlifeLaw.dbo.VIOLATOR_TICKETS
where try_cast(right(CITATION_TIME, 2) as int) >= 60
or (len(CITATION_TIME) = 4 and try_cast(left(CITATION_TIME, 2) as int) >= 24)
or len(CITATION_TIME) > 4