Redis Sets are an unordered collection of unique strings. Unique means sets does not allow repetition of data in a key.
In Redis set add, remove, and test for the existence of members in O(1) (constant time regardless of the number of elements contained inside the Set). The maximum length of a list is 232 – 1 elements (4294967295, more than 4 billion of elements per set).
Example
redis 127.0.0.1:6379> SADD Adglob redis (integer) 1 redis 127.0.0.1:6379> SADD Adglob mongodb (integer) 1 redis 127.0.0.1:6379> SADD Adglob mysql (integer) 1 redis 127.0.0.1:6379> SADD Adglob mysql (integer) 0 redis 127.0.0.1:6379> SMEMBERS Adglob 1) "mysql" 2) "mongodb" 3) "redis"
In the above example, three values are inserted in Redis set named ‘Adglob’ by the command SADD.
Redis Sets Commands
Following table lists some basic commands related to sets.
| Sr.No | Command & Description |
|---|---|
| 1 | SADD keyhttps://adglob.in/blog/redis-set-sadd-command/ Adds one or more members to a set |
| 2 | SCARD keyhttps://adglob.in/blog/redis-set-scard-command/ Gets the number of members in a set |
| 3 | SDIFF https://adglob.in/blog/redis-set-sdiff-command/ Subtracts multiple sets |
| 4 | SDIFFSTORE https://adglob.in/blog/redis-set-sdiffstore-command/ Subtracts multiple sets and stores the resulting set in a key |
| 5 | SINTER key1 https://adglob.in/blog/redis-set-sinter-command/ Intersects multiple sets |
| 6 | SINTERSTORE destination key1 https://adglob.in/blog/redis-set-sinterstore-command/ Intersects multiple sets and stores the resulting set in a key |
| 7 | SISMEMBER key https://adglob.in/blog/redis-set-sismember-command/ Determines if a given value is a member of a set |
| 8 | SMEMBERS keyhttps://adglob.in/blog/redis-set-sismember-command-2/ Gets all the members in a set |
| 9 | SMOVE https://adglob.in/blog/redis-set-smove-command/ Moves a member from one set to another |
| 10 | SPOP keyhttps://adglob.in/blog/redis-set-spop-command/ Removes and returns a random member from a set |
| 11 | SRANDMEMBER key https://adglob.in/blog/redis-set-srandmember-command/ Gets one or multiple random members from a set |
| 12 | SREM keyhttps://adglob.in/blog/redis-set-srem-command/ Removes one or more members from a set |
| 13 | SUNIONhttps://adglob.in/blog/redis-set-sunion-command/ Adds multiple sets |
| 14 | SUNIONSTORE https://adglob.in/blog/redis-set-sunionstore-command/ Adds multiple sets and stores the resulting set in a key |
| 15 | SSCAN key https://adglob.in/blog/redis-set-sscan-command/ Incrementally iterates set elements |