yangzhg opened a new issue #3483: URL: https://github.com/apache/incubator-doris/issues/3483
if the subquery of case when clause in when condition and it returns empty set, then the whole query return empty set, this is because doris rewrite subquery in case when to cross join, if a subqery return empty the cross join return empty. e.g. ``` select case when (select k1 sum from t1 where k1 <0) > t2. then t2.k1 else 0 end a from t2; ``` this query will rewrite to ``` select case when tt.k1 > t2. then t2.k1 else 0 end a from t2, (select k1 sum from t1 where k1 <0 ) as tt; ``` if `select k1 sum from t1 where k1 <0` is an empty set, then the query is empty, but in mysql this returns `else 0` branch as the resulet. in doris we can not handle subquery very well, so shoud report an error when subquery is empty ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
