Redis Sorted Sets: ZSCAN

ZSCAN key cursor [MATCH pattern] [COUNT count]

Redis ZSCAN command iterates elements of Sorted Set types and their associated scores.

Basic usage of SSCAN

• ZSCAN is a cursor based iterator. This means that at every call of the command, the server returns an updated cursor that the user needs to use as the cursor argument in the next call.
• An iteration starts when the cursor is set to 0, and terminates when the cursor returned by the server is 0. The following is an example of ZSCAN iteration:

Syntax:

ZSCAN key cursor [MATCH pattern] [COUNT count]

Available since

2.8.0.

Return Value

Array reply.

Return Value Type

Array

Example: Redis ZSCAN

127.0.0.1:6379> ZADD mytestset 1 M1 2 M2 3 M3 4 N1 5 N2 6 N3 7 O1 8 O2 9 O3
(integer) 9
127.0.0.1:6379> ZSCAN mytestset 0
1) "0"
2)  1) "M1"
    2) "1"
    3) "M2"
    4) "2"
    5) "M3"
    6) "3"
    7) "N1"
    8) "4"
    9) "N2"
   10) "5"
   11) "N3"
   12) "6"
   13) "O1"
   14) "7"
   15) "O2"
   16) "8"
   17) "O3"
   18) "9"

Example: Redis ZSCAN: using count

127.0.0.1:6379> ZSCAN mytestset 0 COUNT 5
1) "0"
2)  1) "M1"
    2) "1"
    3) "M2"
    4) "2"
    5) "M3"
    6) "3"
    7) "N1"
    8) "4"
    9) "N2"
   10) "5"
   11) "N3"
   12) "6"
   13) "O1"
   14) "7"
   15) "O2"
   16) "8"
   17) "O3"
   18) "9"

Example: Redis ZSCAN: using pattern

127.0.0.1:6379> ZSCAN mytestset 0 COUNT 5
1) "0"
2)  1) "M1"
    2) "1"
    3) "M2"
    4) "2"
    5) "M3"
    6) "3"
    7) "N1"
    8) "4"
    9) "N2"
   10) "5"
   11) "N3"
   12) "6"
   13) "O1"
   14) "7"
   15) "O2"
   16) "8"
   17) "O3"
   18) "9"
127.0.0.1:6379>
127.0.0.1:6379> ZSCAN mytestset 0 MATCH N*
1) "0"
2) 1) "N1"
   2) "4"
   3) "N2"
   4) "5"
   5) "N3"
   6) "6"
127.0.0.1:6379> ZSCAN mytestset 0 MATCH *3*
1) "0"
2) 1) "M3"
   2) "3"
   3) "N3"
   4) "6"
   5) "O3"
   6) "9"
127.0.0.1:6379> ZSCAN mytestset 0 MATCH *3* COUNT 20
1) "0"
2) 1) "M3"
   2) "3"
   3) "N3"
   4) "6"
   5) "O3"
   6) "9"

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