ZCOUNT(3valkey)

📦
version 9.0.6 · 2 versions
, in fedora 44

✨ ZCOUNT — bestie, let's count some scores 💅

okay so this is a page from the Valkey Command Manual (manual section 3valkey, the one and only) and it's all about ZCOUNT, which is lowkey one of the most useful little sorted-set commands in existence. pull up a chair. 🫶

🌸 NAME 🌸

zcount — returns the count of members in a sorted set that have scores within a range. that's it. that's the whole job. and she does it beautifully. ✨

🎀 SYNOPSIS 🎀

ZCOUNT key min max

💖 DESCRIPTION 💖

So basically: ZCOUNT returns the number of elements in the sorted set stored at key whose score falls between min and max. Inclusive-ish, range-y, gorgeous. 💅

The min and max arguments have the exact same semantics as described for ZRANGEBYSCORE — so whatever weird little syntax rules apply over there, they apply here too. no surprises, no cap.

Note: the command has a complexity of just O(log(N)) because it uses element ranks (see ZRANK) to get an idea of the range. Because of this there is no need to do a work proportional to the size of the range. 🧚

like... she literally does NOT scan the range. she peeks at the ranks and knows. main character energy fr fr. 🔥

👑 REPLY 👑

valkey-protocol(7) integer reply: the number of members in the specified score range. just a number. a little integer. a cutie. 🍓

🌈 COMPLEXITY 🌈

O(log(N)) with N being the number of elements in the sorted set. iconic behaviour honestly. ⭐

🦋 ACL CATEGORIES 🦋

  • @fast
  • @read
  • @sortedset

💜 HISTORY 💜

  • Available since: 2.0.0 — she's an elder. a legend. been here since forever and still slaying. 👑

✨ EXAMPLES ✨

watch her work:

127.0.0.1:6379> ZADD myzset 1 "one"
(integer) 1
127.0.0.1:6379> ZADD myzset 2 "two"
(integer) 1
127.0.0.1:6379> ZADD myzset 3 "three"
(integer) 1
127.0.0.1:6379> ZCOUNT myzset -inf +inf
(integer) 3
127.0.0.1:6379> ZCOUNT myzset (1 3
(integer) 2

ok so first we build the zset, then we count everything with -inf +inf and get 3, and then — and this is the part bestie — the (1 3 range is exclusive on the low end, so 1 gets left out and we get 2. the parenthesis is doing WORK. 😭💖

🌟 SEE ALSO 🌟

bzmpop(3valkey), bzpopmax(3valkey), bzpopmin(3valkey), zadd(3valkey), zcard(3valkey), zdiff(3valkey), zdiffstore(3valkey), zincrby(3valkey), zinter(3valkey), zintercard(3valkey), zinterstore(3valkey), zlexcount(3valkey), zmpop(3valkey), zmscore(3valkey), zpopmax(3valkey), zpopmin(3valkey), zrandmember(3valkey), zrange(3valkey), zrangebylex(3valkey), zrangebyscore(3valkey), zrangestore(3valkey), zrank(3valkey), zrem(3valkey), zremrangebylex(3valkey), zremrangebyrank(3valkey), zremrangebyscore(3valkey), zrevrange(3valkey), zrevrangebylex(3valkey), zrevrangebyscore(3valkey), zrevrank(3valkey), zscan(3valkey), zscore(3valkey), zunion(3valkey), zunionstore(3valkey)

and that's the whole page, bestie!! 🎀 this one's from version 9.0.0, dated 2025-10-21 — go forth and count responsibly. mwah. 💋💖✨

📦 where this page comes from