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ZREVRANGEBYLEX

Returns a range of members in a sorted set, by lexicographical order, within the given range, ordered from higher to lower strings.

Syntax​

ZREVRANGEBYLEX key max min [LIMIT offset count]

Parameters​

  • key: The name of the sorted set.
  • max: The maximum lexicographical value (inclusive) of the range. The range can be inclusive ([value) or exclusive ((value).
  • min: The minimum lexicographical value (inclusive) of the range. The range can be inclusive ([value) or exclusive ((value).
  • LIMIT offset count: Optional. Specifies the number of members to return starting from the offset. If not provided, the entire range is returned.

Details​

  • Available since: 2.8.9
  • Time complexity: O(log(N) + M) where N is the number of elements in the sorted set, and M is the number of elements being returned.
  • ACL categories: @read, @sortedset, @slow

The ZREVRANGEBYLEX command retrieves members in a sorted set stored at key within the specified lexicographical range, ordered from higher to lower strings. This command is useful when the elements in the sorted set are strings, and you want to perform a reverse range query on those strings.

Special Range Syntax​

  • Inclusive Range: Use [ followed by the value (e.g., [z).
  • Exclusive Range: Use ( followed by the value (e.g., (z).
  • Unbounded Range: Use + for the maximum and - for the minimum to specify an open-ended range.

Examples​

Basic Usage​

Assume we have a sorted set called myzset with the following members:

ZADD myzset 0 "apple" 0 "banana" 0 "cherry" 0 "date" 0 "fig"

To retrieve members between "date" and "banana" in reverse lexicographical order:

ZREVRANGEBYLEX myzset [date [banana

This will return:

1) "date"
2) "cherry"
3) "banana"

Using Exclusive Range​

To retrieve members between "date" (exclusive) and "banana" (exclusive) in reverse order:

ZREVRANGEBYLEX myzset (date (banana

This will return:

1) "cherry"

Using Unbounded Range​

To retrieve all members down to "cherry" in reverse lexicographical order:

ZREVRANGEBYLEX myzset [fig -

This will return:

1) "fig"
2) "date"
3) "cherry"
4) "banana"
5) "apple"

Using LIMIT​

To retrieve the first two members starting from "date" in reverse order:

ZREVRANGEBYLEX myzset [date [banana LIMIT 0 2

This will return:

1) "date"
2) "cherry"

Edge Cases​

  • If min is greater than max in lexicographical order, ZREVRANGEBYLEX returns an empty array.
  • If the key does not exist, ZREVRANGEBYLEX returns an empty array.
  • If the key exists but is not a sorted set, an error is returned.

RESP2/RESP3 Reply​

  • Array reply: list of members in the specified lexicographical range, ordered from higher to lower.