DATEADD should support fractional value for MILLISECOND [CORE4457]

[firebird-issue-importer]

Submitted by: @mrotteveel

Timestamps in Firebird have a 100 microsecond resolution, however the built-in DATEADD takes only integer values this makes it impossible to modify the 100 microsecond value of a TIMESTAMP.

For example:

SELECT CAST(DATEADD(-1 * EXTRACT(MILLISECOND FROM ts) MILLISECOND TO ts) AS VARCHAR(30)), EXTRACT(MILLISECOND FROM ts)
FROM (
SELECT TIMESTAMP'2014-06-09 13:50:17.4971' as ts
FROM RDB$DATABASE
) a

has output:
2014-06-09 13:50:17.0001 497.1

I would expect (or prefer) output:
2014-06-09 13:50:17.0000

Commits: 33a9510 FirebirdSQL/fbt-repository@06b88e0

[firebird-issue-importer]

Modified by: @asfernandes

assignee: Adriano dos Santos Fernandes [ asfernandes ]

[firebird-issue-importer]

Modified by: @asfernandes

status: Open [ 1 ] => Resolved [ 5 ]

resolution: Fixed [ 1 ]

Fix Version: 3.0 Beta 1 [ 10332 ]

[firebird-issue-importer]

Modified by: @pavel-zotov

status: Resolved [ 5 ] => Resolved [ 5 ]

QA Status: Done successfully

[firebird-issue-importer]

Modified by: @pavel-zotov

status: Resolved [ 5 ] => Closed [ 6 ]