Which statement is true regarding the UNION operator?
A.
By default, the output is not sorted
B.
NULL values are not ignored during duplicate checking
C.
Names of all columns must be identical across all SELECT statements
D.
The number of columns selected in all SELECT statements need to be the same
“D” looks to be true as well…
agreed.
C and D says thay ‘all SELECT’. The select can be in a subquery