[
https://issues.apache.org/jira/browse/DRILL-6242?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16455608#comment-16455608
]
ASF GitHub Bot commented on DRILL-6242:
---------------------------------------
Github user jiang-wu commented on the issue:
https://github.com/apache/drill/pull/1184
@parthchandra Just to clarify on the JDBC comment. What do you mean by
"Json representation"? Do you instead mean the "Local[Date|Time]" class
representation? There are no "Json" being returned from the JDBC layer. It
uses Java collections Map or List objects. Inside the Map | List, the change
in this pull request properly uses objects of different classes: Local
[Date|Time|DateTime] to represent the various date/time/timestamp values.
So far so good. Now, it is possible in the future, we may want to further
translate the Local [Date|Time|DateTime] objects inside the Map|List to
java.sql.[Date|Time|Timestamp] upon access. But to do that inside the
SqlAccessor, you would need to deep copy the Map|List and build another version
with the date|time translated into java.sql.date|time. That would seem like a
lot of work for little gain.
I would say let's hold off on that for now. A few databases seem to be
moving toward using non-timezone based representation in JDBC if the database
does not support timezones:
https://jdbc.postgresql.org/documentation/head/8-date-time.html It would make
sense to consider changing the class used after deciding on what to do with
Drill handling of timezones.
> Output format for nested date, time, timestamp values in an object hierarchy
> ----------------------------------------------------------------------------
>
> Key: DRILL-6242
> URL: https://issues.apache.org/jira/browse/DRILL-6242
> Project: Apache Drill
> Issue Type: Bug
> Components: Execution - Data Types
> Affects Versions: 1.12.0
> Reporter: Jiang Wu
> Assignee: Jiang Wu
> Priority: Major
> Fix For: 1.14.0
>
>
> Some storages (mapr db, mongo db, etc.) have hierarchical objects that
> contain nested fields of date, time, timestamp types. When a query returns
> these objects, the output format for the nested date, time, timestamp, are
> showing the internal object (org.joda.time.DateTime), rather than the logical
> data value.
> For example. Suppose in MongoDB, we have a single object that looks like
> this:
> {code:java}
> > db.test.findOne();
> {
> "_id" : ObjectId("5aa8487d470dd39a635a12f5"),
> "name" : "orange",
> "context" : {
> "date" : ISODate("2018-03-13T21:52:54.940Z"),
> "user" : "jack"
> }
> }
> {code}
> Then connect Drill to the above MongoDB storage, and run the following query
> within Drill:
> {code:java}
> > select t.context.`date`, t.context from test t;
> +--------+---------+
> | EXPR$0 | context |
> +--------+---------+
> | 2018-03-13 |
> {"date":{"dayOfYear":72,"year":2018,"dayOfMonth":13,"dayOfWeek":2,"era":1,"millisOfDay":78774940,"weekOfWeekyear":11,"weekyear":2018,"monthOfYear":3,"yearOfEra":2018,"yearOfCentury":18,"centuryOfEra":20,"millisOfSecond":940,"secondOfMinute":54,"secondOfDay":78774,"minuteOfHour":52,"minuteOfDay":1312,"hourOfDay":21,"zone":{"fixed":true,"id":"UTC"},"millis":1520977974940,"chronology":{"zone":{"fixed":true,"id":"UTC"}},"afterNow":false,"beforeNow":true,"equalNow":false},"user":"jack"}
> |
> {code}
> We can see that from the above output, when the date field is retrieved as a
> top level column, Drill outputs a logical date value. But when the same
> field is within an object hierarchy, Drill outputs the internal object used
> to hold the date value.
> The expected output is the same display for whether the date field is shown
> as a top level column or when it is within an object hierarchy:
> {code:java}
> > select t.context.`date`, t.context from test t;
> +--------+---------+
> | EXPR$0 | context |
> +--------+---------+
> | 2018-03-13 | {"date":"2018-03-13","user":"jack"} |
> {code}
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
