SQL to JSON datetime conversion queries

SQL to JSON datetime queries.sql

DECLARE @sqlData datetime2 = '2017-03-28 12:45:00.1234567'

-- Let's first try the simplest SQL to JSON conversion first using FOR JSON PATH
SELECT @sqlData as SQLDateTime2 FOR JSON PATH
-- Output: [{"SQLDateTime2":"2017-03-28T12:45:00"}]

-- Honestly that's not too bad!
-- The datetime gets created in the YYYY-MM-DDTHH:MM:SS.fffffff format
-- Although this is pretty much what we need, what if we want to be explicit and specify that we are in UTC?
-- Just add the AT TIME ZONE modifier and we will get our JSON "Z" indicating UTC
SELECT @sqlData AT TIME ZONE 'UTC' AS SQLDateTime2 FOR JSON PATH
-- Output: [{"SQLDateTime2":"2017-03-28T12:45:00.1234567Z"}]

-- And if we provide a different time zone offset, the JSON is formatted correctly with the +/-HH:MM suffix:
SELECT @sqlData AT TIME ZONE 'Eastern Standard Time' AS SQLDateTime2 FOR JSON PATH
-- Output: [{"SQLDateTime2":"2017-03-28T12:45:00.1234567-04:00"}]

-- You might notice that there are 7 fractional second decimal places in all of the above examples.
-- Although out of JSON spec, this is ok!

-- What if we just want to insert the date?  Just specify with a SQL CONVERT()
SELECT CONVERT(date, @sqlData) as SQLDateTime2 FOR JSON PATH
-- Output: [{"SQLDateTime2":"2017-03-28"}]

-- And the same goes with the time portion
SELECT CONVERT(time, @sqlData) as SQLDateTime2 FOR JSON PATH
-- Output: [{"SQLDateTime2":"12:45:00.1234567"}]