[
https://issues.apache.org/jira/browse/FLINK-6895?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16400470#comment-16400470
]
Fabian Hueske commented on FLINK-6895:
--------------------------------------
Returning a superclass does not work because Flink generates de/serializers
based on the type. We would lose information that way.
I don't think we had a case yet where the return type of a function depends on
the value of a parameter (in contrast to the type of a parameter).
[~twalthr] any ideas?
> Add STR_TO_DATE supported in SQL
> --------------------------------
>
> Key: FLINK-6895
> URL: https://issues.apache.org/jira/browse/FLINK-6895
> Project: Flink
> Issue Type: Sub-task
> Components: Table API & SQL
> Affects Versions: 1.4.0
> Reporter: sunjincheng
> Assignee: Aegeaner
> Priority: Major
>
> STR_TO_DATE(str,format) This is the inverse of the DATE_FORMAT() function. It
> takes a string str and a format string format. STR_TO_DATE() returns a
> DATETIME value if the format string contains both date and time parts, or a
> DATE or TIME value if the string contains only date or time parts. If the
> date, time, or datetime value extracted from str is illegal, STR_TO_DATE()
> returns NULL and produces a warning.
> * Syntax:
> STR_TO_DATE(str,format)
> * Arguments
> **str: -
> **format: -
> * Return Types
> DATAETIME/DATE/TIME
> * Example:
> STR_TO_DATE('01,5,2013','%d,%m,%Y') -> '2013-05-01'
> SELECT STR_TO_DATE('a09:30:17','a%h:%i:%s') -> '09:30:17'
> * See more:
> ** [MySQL|
> https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_str-to-date]
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
