WHERE EXISTS ( ... subquery ...) not supported and error message is confusing #6852
Description
https://www.w3schools.com/sql/sql_exists.asp
ClickHouse doesn't support such a queries and thinks that 'exists' is a column name:
select * from system.one where exists (select 1);
Expected one of: LIKE, GLOBAL NOT IN, AS, IS, OR, QuestionMark, BETWEEN, NOT LIKE, AND, Comma, alias, IN, Dot, NOT, Arrow, token, NOT IN, GLOBAL IN
select * from system.one where exists;
Received exception from server (version 19.14.1):
Code: 47. DB::Exception: Received from localhost:9000. DB::Exception: Missing columns: 'exists' while processing query: 'SELECT dummy FROM system.one WHERE exists', required columns: 'dummy' 'exists', source columns: 'dummy'.
0 rows in set. Elapsed: 0.011 sec.
PS. Not important, issue is just to document that behaviour.