Increments the score of member in the sorted set stored at key by
increment. If member does not exist in the sorted set, it is added with
increment as its score (as if its previous score was 0.0). If key does
not exist, a new sorted set with the specified member as its sole member is
created.
An error is returned when key exists but does not hold a sorted set.
The score value should be the string representation of a numeric value, and
accepts double precision floating point numbers. It is possible to provide a
negative value to decrement the score.
Return value
Bulk reply: the new score of member (a double precision floating point
number), represented as string.
Examples
redis>
ZADD myzset 1 "one"
(integer) 1redis> ZADD myzset 2 "two"
(integer) 1redis> ZINCRBY myzset 2 "one"
"3"redis> ZRANGE myzset 0 -1 WITHSCORES
1) "two" 2) "2" 3) "one" 4) "3"