ZREM key member [member...]
This command removes the
members specified in the sorted set at
key and returns the number of
Members specified that do not exist in key are ignored. If
key does not exist, 0 is returned.
key is associated with non sorted-set data, an error is returned.
The number of
members removed from the sorted set.
$ ZADD z_key 1.0 v1 2.0 v2
$ ZREM z_key v2 v3
$ ZREM z_key v1 v2 v3
$ ZCARD z_key