回复：Flink tableApi/sql calendar

[xueyu <27...@qq.com>]

hi, Sergey,


I tried on my local mysql query  `select timestampadd(YEAR,-1000,'2017-11-29 22:58:58.998');` it looks that the result of mysql is "1017-11-29 22:58:58.998000". I don't know why the results of us are different...





Maybe I could not answer your question, however there are some other info about time in flink you could refer. One is that flink should support time zone [1] and it seems that flink has julian process function [2]


Thanks




[1] https://issues.apache.org/jira/browse/FLINK-8353?jql=project%20%3D%20FLINK%20AND%20resolution%20%3D%20Unresolved%20AND%20creator%20in%20(twalthr)%20ORDER%20BY%20priority%20DESC%2C%20updated%20DESC


[2] https://github.com/apache/flink/blob/master/flink-libraries/flink-table/src/main/java/org/apache/calcite/avatica/util/DateTimeUtils.java#L365




------------------ 原始邮件 ------------------
发件人: "Sergey Nuyanzin"<sn...@gmail.com>;
发送时间: 2018年8月26日(星期天) 上午7:19
收件人: "dev"<de...@flink.apache.org>;

主题: Flink tableApi/sql calendar



Hello,

I have just faced with a question: what calendar is used by Flink
tableAPI/sql?
For instance there was a TIMESTAMPADD related issue [1] with references to
MySql documentation. However there are some contradictions like:
from one side there is a testTimestampAdd[2] in Flink which expects
1017-11-29 after adding -1000 years. From the other side there is MySql
documentation about their calendar [3] and result of the same query
1017-12-05T22:58:58.998 vs expected by Flink's test 2017-11-29 22:58:58.998

Should it be treated as an issue or just another calendar usage (without
Gregorian cutover e.g.)?

[1] https://issues.apache.org/jira/browse/FLINK-6811
[2]

https://github.com/apache/flink/blob/505dca174128ebb3bf765778ee36d58f680d6a1e/flink-libraries/flink-table/src/test/scala/org/apache/flink/table/expressions/ScalarFunctionsTest.scala#L2166


[3] https://dev.mysql.com/doc/refman/5.5/en/mysql-calendar.html
Best regards,
Sergey