While in SQL DISTINCT applies to the result set, in CQL it applies
to the table being selected, and doesn't allow GROUP BY with clustering
keys. So reject the combination like Cassandra does.
While this is not an important issue to fix, it blocks un-xfailing
other issues, so I'm clearing it ahead of fixing those issues.
An issue is unmarked as xfail, and other xfails lose this issue
as a blocker.
Fixes#12479Closes#14970
This patch adds a few simple functional test for the SELECT DISTINCT
feature, and how it interacts with other features especiall GROUP BY.
2 of the 5 new tests are marked xfail, and reproduce one old and one
newly-discovered issue:
Refs #5361: LIMIT doesn't work when using GROUP BY (the test here uses
LIMIT and GROUP BY together with SELECT DISTINCT, so the
LIMIT isn't honored).
Refs #12479: SELECT DISTINCT doesn't refuse GROUP BY with clustering
column.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes#12480
