ZrangebyscoreCommand

- -

- ï»¿#sidebar SortedSetCommandsSidebar

ZRANGEBYSCORE _key_ _min_ _max_ `[`LIMIT _offset_ _count_`]` (Redis >

1.1) = -

ZRANGEBYSCORE _key_ _min_ _max_ `[`LIMIT _offset_ _count_`]` `[`WITHSCORES`]` (Redis >

1.3.4) = -

ZCOUNT _key_ _min_ _max_

-Time complexity: O(log(N))+O(M) with N being the number of elements in the sorted set and M the number of elements returned by the command, so if M is constant (for instance you always ask for the first ten elements with LIMIT) you can consider it O(log(N))

Return the 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 having the same score are returned sorted lexicographically asASCII strings (this follows from a property of Redis sorted sets and does notinvolve further computation).

Using the optional LIMIT it's possible to get only a range of the matchingelements in an SQL-alike way. Note that if offset is large the commandsneeds to traverse the list for offset elements and this adds up to theO(M) figure.

The ZCOUNT command is similar to ZRANGEBYSCORE but instead of returningthe actual elements in the specified interval, it just returns the numberof matching elements.

Exclusive intervals and infinity

-min and max can be -inf and +inf, so that you are not required to know what's the greatest or smallest element in order to take, for instance, elements "up to a given value".

Also while the interval is for default closed (inclusive) it's possible to specify open intervals prefixing the score with a "(" character, so for instance: -

-ZRANGEBYSCORE zset (1.3 5
-

-Will return all the values with score > 1.3 and <= 5, while for instance: -

-ZRANGEBYSCORE zset (5 (10
-

-Will return all the values with score > 5 and < 10 (5 and 10 excluded). -

Return value

ZRANGEBYSCORE returns a Multi bulk reply specifically a list of elements in the specified score range.

ZCOUNT returns a Integer reply specifically the number of elements matching the specified score range. -

Examples

-redis> zadd zset 1 foo
-(integer) 1
-redis> zadd zset 2 bar
-(integer) 1
-redis> zadd zset 3 biz
-(integer) 1
-redis> zadd zset 4 foz
-(integer) 1
-redis> zrangebyscore zset -inf +inf
-1. "foo"
-2. "bar"
-3. "biz"
-4. "foz"
-redis> zcount zset 1 2
-(integer) 2
-redis> zrangebyscore zset 1 2
-1. "foo"
-2. "bar"
-redis> zrangebyscore zset (1 2
-1. "bar"
-redis> zrangebyscore zset (1 (2
-(empty list or set)
-

- -