Hi Flink folks,

We have a custom date formatting function that we use to format the output
of columns containing dates. Ideally what we want is to format the output
in the select statement but be able to order by the underlying datetime (so
that and output with formatted dates "February 2019" and "April 2019" is
guaranteed to have the rows sorted in time order rather than alphabetical
order).

When I go to add the unformatted column to the order by, however, that gets
appended as an extra column to the select statement during the query
planning process within Calcite. (In the order by parsing, it's considering
this a different column from the one in the select statement.) When the
group by column is different in the same way but there's no order by
column, the extra column isn't added. I've included a couple of simple
examples below.

Is this the intended behavior of the query planner? Does anyone know of a
way around this without needing to change the formatting so that it makes
the output dates correctly sortable?

Thanks for your help!

Morrisa



Example query and output with order by using formatted date:

SELECT

formatDate(floor(`testTable`.`timestamp` TO MONTH), 'MONTH'),

sum(`testTable`.`count`)

FROM `testTable`

GROUP BY formatDate(floor(`testTable`.`timestamp` TO MONTH), 'MONTH')

ORDER BY formatDate(floor(`testTable`.`timestamp` TO MONTH), 'MONTH') ASC

Month

SUM VALUE

April 2019

1052

February 2019

1


Example query and output without order by but group by using unformatted
date:

SELECT

formatDate(floor(`testTable`.`timestamp` TO MONTH), 'MONTH'),

sum(`testTable`.`count`)

FROM `testTable`

GROUP BY floor(`testTable`.`timestamp` TO MONTH)

Month

SUM VALUE

February 2019

1

April 2019

1052

We would like to enforce the ordering, so although this output is what we
want, I don't think we can use this solution.

Example query and output with order by using unformatted date:

SELECT

formatDate(floor(`testTable`.`timestamp` TO MONTH), 'MONTH'),

sum(`testTable`.`count`)

FROM `testTable`

GROUP BY floor(`testTable`.`timestamp` TO MONTH)

ORDER BY floor(`testTable`.`timestamp` TO MONTH) ASC

Month

SUM VALUE

February 2019

1

2/1/2019 12:00 AM

April 2019

1052

4/1/2019 12:00 AM


-- 
Morrisa Brenner
Software Engineer
225 Franklin St, Boston, MA 02110
klaviyo.com <https://www.klaviyo.com>
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