[ 
https://issues.apache.org/jira/browse/FLINK-34147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17810723#comment-17810723
 ] 

Jark Wu commented on FLINK-34147:
---------------------------------

I agree it is ambiguous. Currently, {{TimestampData}} represents both 
{{Instant}} and {{LocalDateTime}}. 
* When it represents as an {{Instant}}, you can use conversion methods 
{{fromInstant()/toInstant()}} to convert an {{Instant}} to {{TimestampData}}, 
but do not use {{fromLocalDateTime()/toLocalDateTime()}}. 
* When it represents as an {{LocalDateTime}}, you can use conversion methods 
{{fromLocalDateTime()/toLocalDateTime()}} to convert a {{LocalDateTime}} to 
{{TimestampData}}, but do not use {{fromInstant()/toInstant()}}. 

Therefore, if you have a Java {{LocalDateTime}} and want to convert it into an 
Instant {{TimestampData}}, you need to convert the {{LocalDateTime}} into Java 
{{Instant}} with a specific time zone first. And then use the {{Instant}} to 
create the {{TimestampData}}.

This is not very clear from the javadoc of {{TimestampData}} and I agree we 
need to improve the doc. 

> TimestampData to/from LocalDateTime is ambiguous
> ------------------------------------------------
>
>                 Key: FLINK-34147
>                 URL: https://issues.apache.org/jira/browse/FLINK-34147
>             Project: Flink
>          Issue Type: Bug
>          Components: Table SQL / API
>            Reporter: Rui Li
>            Priority: Major
>
> It seems TimestampData is essentially an {{Instant}}. Therefore an implicit 
> time zone is used in the {{fromLocalDateTime}} and {{toLocalDateTime}} 
> methods. However neither the method name nor the API doc indicates which time 
> zone is used. So from caller's perspective, the results of these two methods 
> are ambiguous.



--
This message was sent by Atlassian Jira
(v8.20.10#820010)

Reply via email to