SUNIONSTORE - Upstash Documentation

Use SUNIONSTORE to compute the union of sets and store it in another key.

The destination is overwritten if it exists and deleted when the union is empty, and the reply is the number of members stored. Materializing the union is the usual way to build a combined audience once and then intersect or difference it with other sets, instead of recomputing it on every query.

Syntax#

SUNIONSTORE <destination> <key> [<key> ...]

Arguments#

Argument	Required	Repeatable	Description
`<destination>`	Yes	No	Redis key used as destination.
`<key>`	Yes	Yes	Redis key targeted by the command.

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	Integer
RESP3	Integer

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

SUNIONSTORE destination set1 set2

@upstash/redis

import { Redis } from "@upstash/redis";const redis = Redis.fromEnv();await redis.sadd("set1", "a", "b", "c");await redis.sadd("set2", "c", "d", "e");await redis.sunionstore("destination", "set1", "set2");

upstash_redis

from upstash_redis import Redisredis = Redis.from_env()result = redis.sunionstore("destination-key", "my-key")print(result)

ioredis

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

redis-py

import osimport redisclient = redis.from_url(os.environ["REDIS_URL"])result = client.sunionstore("destination-key", ["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.SUnionStore(context.Background(), "destination-key", "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.sunionstore("destination-key", "my-key");  System.out.println(result);}

redis-rs

use redis::TypedCommands;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 result = connection.sunionstore("destination-key", &["my-key"])?;    println!("{result:?}");    Ok(())}