What is set function in sql .E.g.What is difference between
union and union all

Answer Posted / veki

set operators are used to combine the out put of more than
one query.

union: used to combine the output Query1 and query2
and display them uniquely AND OUTPUT IS SORTED
ACCORDING TO FIRST COLUMN OF QUERY1

union all : it would combine the two query and displays then
as its duplicates AND HERE NO SORTING IS DONE.

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