-
1.1) =
-
Time complexity: O(log(N))+O(M) with N being the number of elements in the sorted set and M the number of elements matching the min and max scoreReturn 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).
+ #sidebar
SortedSetCommandsSidebar 1.1) =
+
1.3.4) =
+
+
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).
-
Multi bulk reply, specifically a list of elements in the specified score range.
+
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.
+
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).
+
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.
+
+
+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)
+