ZDIFF - Upstash Documentation

Use ZDIFF to get the members of the first sorted set that do not appear in any of the others.

<numkeys> states how many keys follow. Scores come from the first set and are returned only when WITHSCORES is given, and the result keeps the ordering of that set. Keys that do not exist count as empty.

The result is computed on each call and not stored; use ZDIFFSTORE to keep it. This is how you exclude one group from a ranking, for example dropping already-seen items from a scored feed.

Syntax#

ZDIFF <numkeys> <key> [<key> ...] [WITHSCORES]

Arguments#

Argument	Required	Repeatable	Description
`<numkeys>`	Yes	No	Number of key arguments that follow.
`<key>`	Yes	Yes	Redis key targeted by the command.
`WITHSCORES`	No	No	Include sorted-set scores.

Important points#

numkeys must equal the number of key arguments that immediately follow it.
Pair-based results may be flattened into one alternating array in RESP2 while RESP3 preserves nested pairs or a map.
RESP2 represents floating-point reply values as bulk strings; RESP3 may use native double replies. Client libraries commonly decode either form to a language number.

Response#

The reply reports the result of the operation. Error replies have the same shape in RESP2 and RESP3 and are surfaced as exceptions by the SDKs below.

Protocol	Reply
RESP2	Array of members, or flat member/score array with `WITHSCORES`
RESP3	Array of members, or array of member/score pairs with `WITHSCORES`

Note

Client libraries often decode bulk strings, maps, sets, and numeric strings into language-native values. The table describes the Redis wire reply.

Examples#

TCP examples use the TLS REDIS_URL from the Upstash console. REST examples use UPSTASH_REDIS_REST_URL and UPSTASH_REDIS_REST_TOKEN.

Redis CLI

ZDIFF 1 my-key

@upstash/redis

Note

This command is not supported yet in @upstash/redis.

upstash_redis

from upstash_redis import Redisredis = Redis.from_env()result = redis.zdiff(["my-key"])print(result)

ioredis

import Redis from "ioredis";const redis = new Redis(process.env.REDIS_URL!);const result = await redis.zdiff("1", "my-key");console.log(result);

node-redis

import { createClient } from "redis";const client = await createClient({ url: process.env.REDIS_URL })  .on("error", console.error)  .connect();const result = await client.zDiff("my-key");console.log(result);

redis-py

import osimport redisclient = redis.from_url(os.environ["REDIS_URL"])result = client.zdiff(["my-key"])print(result)

go-redis

package mainimport (    "context"    "fmt"    "os"    "github.com/redis/go-redis/v9")func main() {    opts, err := redis.ParseURL(os.Getenv("REDIS_URL"))    if err != nil {        panic(err)    }    client := redis.NewClient(opts)    result, err := client.ZDiff(context.Background(), "my-key").Result()    if err != nil {        panic(err)    }    fmt.Println(result)}

jedis

import java.net.URI;import redis.clients.jedis.Jedis;try (Jedis jedis = new Jedis(new URI(System.getenv("REDIS_URL")))) {  Object result = jedis.zdiff("my-key");  System.out.println(result);}

redis-rs

fn main() -> redis::RedisResult<()> {    let url = std::env::var("REDIS_URL").expect("REDIS_URL is not set");    let client = redis::Client::open(url)?;    let mut connection = client.get_connection()?;    let mut command = redis::cmd("ZDIFF");    command.arg("1");    command.arg("my-key");    let result: redis::Value = command.query(&mut connection)?;    println!("{result:?}");    Ok(())}