SDIFFSTORE

计算给定所有集合的差集，并将结果存储在指定的集合中。如果目标集合已存在，则会被覆盖。

Syntax

SDIFFSTORE destination key [key ...]

Return

Integer reply: 结果集合中的元素数量。

Examples

redis> SADD myset1 "a"
(integer) 1
redis> SADD myset1 "b"
(integer) 1
redis> SADD myset1 "c"
(integer) 1
redis> SADD myset2 "c"
(integer) 1
redis> SADD myset2 "d"
(integer) 1
redis> SDIFFSTORE myset3 myset1 myset2
(integer) 2
redis> SMEMBERS myset3
1) "a"
2) "b"
redis> SADD myset1 "d"
(integer) 1
redis> SADD myset2 "e"
(integer) 1
redis> SDIFFSTORE myset3 myset1 myset2
(integer) 2
redis> SMEMBERS myset3
1) "a"
2) "b"