Redis

ZRANGEBYSCORE key min max [WITHSCORES] [LIMIT offset count]

Returns all the elements in the sorted set at key with a score between min and max (including elements with score equal to min or max). The elements are considered to be ordered from low to high scores.

The elements having the same score are returned in lexicographical order (this follows from a property of the sorted set implementation in Redis and does not involve further computation).

The optional LIMIT argument can be used to only get a range of the matching elements (similar to SELECT LIMIT offset, count in SQL). Keep in mind that if offset is large, the sorted set needs to be traversed for offset elements before getting to the elements to return, which can add up to O(N) time complexity.

The optional WITHSCORES argument makes the command return both the element and its score, instead of the element alone. This option is available since Redis 2.0.

Exclusive intervals and infinity

min and max can be -inf and +inf, so that you are not required to know the highest or lowest score in the sorted set to get all elements from or up to a certain score.

By default, the interval specified by min and max is closed (inclusive). It is possible to specify an open interval (exclusive) by prefixing the score with the character (. For example:

ZRANGEBYSCORE zset (1 5

Will return all elements with 1 < score <= 5 while:

ZRANGEBYSCORE zset (5 (10

Will return all the elements with 5 < score < 10 (5 and 10 excluded).

Return value

Array reply: list of elements in the specified score range (optionally with their scores).

Examples

redis>  ZADD myzset 1 "one"
(integer) 1
redis>  ZADD myzset 2 "two"
(integer) 1
redis>  ZADD myzset 3 "three"
(integer) 1
redis>  ZRANGEBYSCORE myzset -inf +inf
1) "one"
2) "two"
3) "three"
redis>  ZRANGEBYSCORE myzset 1 2
1) "one"
2) "two"
redis>  ZRANGEBYSCORE myzset (1 2
1) "two"
redis>  ZRANGEBYSCORE myzset (1 (2
(empty list or set)
redis> 
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