- Usage:
-
ZMPOP numkeys key [ key ... ] 〈 min | max 〉 [ COUNT count ]
- Complexity:
- O(K) + O(M*log(N)) where K is the number of provided keys, N being the number of elements in the sorted set, and M being the number of elements popped.
- Since:
- 7.0.0
ZPOPMINorZPOPMAXwhich take only one key, and can return multiple elements.BZPOPMINorBZPOPMAXwhich take multiple keys, but return only one element from just one key.
Pops one or more elements, that are member-score pairs, from the first non-empty sorted set in the provided list of key names.
ZMPOP and BZMPOP are similar to the following, more limited, commands:
See BZMPOP for the blocking variant of this command.
When the MIN modifier is used, the elements popped are those with the lowest scores from the first non-empty sorted set. The MAX modifier causes elements with the highest scores to be popped.
The optional COUNT can be used to specify the number of elements to pop, and is set to 1 by default.
The number of popped elements is the minimum from the sorted set's cardinality and COUNT's value.
Examples
127.0.0.1:6379> ZMPOP 1 notsuchkey MIN
(nil)
127.0.0.1:6379> ZADD myzset 1 "one" 2 "two" 3 "three"
(integer) 3
127.0.0.1:6379> ZMPOP 1 myzset MIN
1) "myzset"
2) 1) 1) "one"
2) "1"
127.0.0.1:6379> ZRANGE myzset 0 -1 WITHSCORES
1) "two"
2) "2"
3) "three"
4) "3"
127.0.0.1:6379> ZMPOP 1 myzset MAX COUNT 10
1) "myzset"
2) 1) 1) "three"
2) "3"
2) 1) "two"
2) "2"
127.0.0.1:6379> ZADD myzset2 4 "four" 5 "five" 6 "six"
(integer) 3
127.0.0.1:6379> ZMPOP 2 myzset myzset2 MIN COUNT 10
1) "myzset2"
2) 1) 1) "four"
2) "4"
2) 1) "five"
2) "5"
3) 1) "six"
2) "6"
127.0.0.1:6379> ZRANGE myzset 0 -1 WITHSCORES
(empty array)
127.0.0.1:6379> ZMPOP 2 myzset myzset2 MAX COUNT 10
(nil)
127.0.0.1:6379> ZRANGE myzset2 0 -1 WITHSCORES
(empty array)
127.0.0.1:6379> EXISTS myzset myzset2
(integer) 0