
Danny Zhang
2,014 PointsEXCEPT will return duplicate rows in table 1? or just unique rows in table 1?
select * from table 1 except select * from table 2
what if there are duplicate rows in table 1 but not in table 2? what will this query return?
1 Answer

Steven Parker
205,178 PointsEXCEPT
will only return unique items from table 1 that are not in table 2.
This came up recently in this other question where I explain that the video examples for EXCEPT
are incorrect, and show a correct Venn diagram for it.