Adds one or more members to a set. Creates the key if it doesn’t exist.
SADD
key member
[member…]
Add the specified members to the set stored at key
.
Specified members that are already a member of this set are ignored. If
key
does not exist, a new set is created before adding the
specified members.
An error is returned when the value stored at key
is not
a set.
Integer reply: the number of elements that were added to the set, not including all the elements already present in the set.
O(1) for each element added, so O(N) to add N elements when the command is called with multiple arguments.
@fast @set @write
127.0.0.1:6379> SADD myset "Hello"
(integer) 1
127.0.0.1:6379> SADD myset "World"
(integer) 1
127.0.0.1:6379> SADD myset "World"
(integer) 0
127.0.0.1:6379> SMEMBERS myset
1) "Hello"
2) "World"
member
arguments.SCARD, SDIFF, SDIFFSTORE, SINTER, SINTERCARD, SINTERSTORE, SISMEMBER, SMEMBERS, SMISMEMBER, SMOVE, SPOP, SRANDMEMBER, SREM, SSCAN, SUNION, SUNIONSTORE.