Redis Sdiff Command

Redis Sets (Set)

The Redis Sdiff command returns the difference between the first set and other sets, which can also be said to be the unique elements in the first set. Non-existing set key will be treated as an empty set.

The result of the difference set comes from the FIRST_KEY in front, not the OTHER_KEY behind1It is neither the entire FIRST_KEY OTHER_KEY1..OTHER_KEYN of the difference set.

Example:

key1　= {a,b,c,d}
key2　= {c}
key3　= {a,c,e}
SDIFF key1　key2　key3　= {b,d}

Syntax

Basic syntax of the redis Sdiff command is as follows:

redis　127.0.0.1:6379> SDIFF FIRST_KEY OTHER_KEY1..OTHER_KEYN

Available Version

>= 1.0.0

Return Value

List containing the members of the difference set.

Online Examples

redis> SADD key1　"a"
(integer)　1
redis> SADD key1　"b"
(integer)　1
redis> SADD key1　"c"
(integer)　1
redis> SADD key2　"c"
(integer)　1
redis> SADD key2　"d"
(integer)　1
redis> SADD key2　"e"
(integer)　1
redis> SDIFF key1　key2
1) "a"
2) "b"
redis>

Redis Sets (Set)