Returns the members of the set resulting from the union of all the given sets.
For example:
key1 = {a,b,c,d}
key2 = {c}
key3 = {a,c,e}
SUNION key1 key2 key3 = {a,b,c,d,e}
Keys that do not exist are considered to be empty sets.
*Return value
Array reply: list with members of the resulting set.
*Examples
redis>
SADD key1 "a"
(integer) 1redis> SADD key1 "b"
(integer) 1redis> SADD key1 "c"
(integer) 1redis> SADD key2 "c"
(integer) 1redis> SADD key2 "d"
(integer) 1redis> SADD key2 "e"
(integer) 1redis> SUNION key1 key2
1) "c" 2) "e" 3) "b" 4) "a" 5) "d"