best way to replace redis set value

Question

I want to store a key-values type data into redis, values is a set type which means no duplicate value. I opereate in redis like this:

127.0.0.1:6379> sadd a 1 2 3
(integer) 3
127.0.0.1:6379> smembers a
1) "1"
2) "2"
3) "3"
127.0.0.1:6379> sadd a 4 5 6
(integer) 3
127.0.0.1:6379> smembers a
1) "3"
2) "2"
3) "4"
4) "5,"
5) "1"
6) "6"

I want user set(4,5,6) replace set(1,2,3).

Answer 1

Your question is ambiguous.

If your intention is to replace all members:

# Setup "a" with 3 members
127.0.0.1:6379> del a
(integer) 1
127.0.0.1:6379> sadd a 1 2 3
(integer) 3

# Actions - delete entire set and add 3 new members in one go
127.0.0.1:6379> multi
OK
127.0.0.1:6379> del a
QUEUED
127.0.0.1:6379> sadd a 4 5 6
QUEUED
127.0.0.1:6379> exec
1) (integer) 1
2) (integer) 3
127.0.0.1:6379> smembers a
1) "4"
2) "5"
3) "6"

If your intention is to replace only specific members:

# Setup "a" with 4 members
127.0.0.1:6379> del a
(integer) 1
127.0.0.1:6379> sadd a 0 1 2 3
(integer) 4

# Actions - delete 3 specific members and add 3 more, leaving others unaffected
127.0.0.1:6379> multi
OK
127.0.0.1:6379> srem a 1 2 3
QUEUED
127.0.0.1:6379> sadd a 4 5 6
QUEUED
127.0.0.1:6379> exec
1) (integer) 3
2) (integer) 3
127.0.0.1:6379> smembers a
1) "0"
2) "4"
3) "5"
4) "6"
127.0.0.1:6379>