Redis zlexcount 命令
ZLEXCOUNT key min max
When all the elements in a sorted set are inserted with the same score, in order to force lexicographical ordering, this command returns the number of elements in the sorted set at
key with a value between
max arguments have the same meaning as described for ZRANGEBYLEX.
Note: the command has a complexity of just O(log(N)) because it uses elements ranks (see ZRANK) to get an idea of the range. Because of this there is no need to do a work proportional to the size of the range.
Integer reply: the number of elements in the specified score range.
redis> ZADD myzset 0 f 0 g
redis> ZLEXCOUNT myzset – +
redis> ZLEXCOUNT myzset [b [f