Hi, I'm puzzled by two queries returning duplicate rows:
1)
SELECT LIST('Hi') FROM RDB$DATABASE
UNION
SELECT LIST('Hi') FROM RDB$DATABASE
2)
WITH TMP(DuplicateRows) AS
(SELECT LIST('Hi') FROM RDB$DATABASE
UNION
SELECT LIST('Hi') FROM RDB$DATABASE)
SELECT DISTINCT DuplicateRows
FROM TMP
I was certain UNION (as opposed to UNION ALL) should remove duplicates and
the same with DISTINCT. To get the latter query to return one row, GROUP BY
can be added, I don't know how to make the first query return only one row.
Is this a Firebird error, and if so, is it a new one or one fixed in newer
versions?
Set
