hash.js

const Redis = require("ioredis");
const redis = new Redis();

async function main() {
  const user = {
    name: "Bob",
    // The field of a Redis Hash key can only be a string.
    // We can write `age: 20` here but ioredis will convert it to a string anyway.
    age: "20",
    description: "I am a programmer",
  };

  await redis.hmset("user-hash", user);

  const name = await redis.hget("user-hash", "name");
  console.log(name); // "Bob"

  const age = await redis.hget("user-hash", "age");
  console.log(age); // "20"

  const all = await redis.hgetall("user-hash");
  console.log(all); // { age: '20', name: 'Bob', description: 'I am a programmer' }

  // or `await redis.hdel("user-hash", "name", "description")`;
  await redis.hdel("user-hash", ["name", "description"]);

  const exists = await redis.hexists("user-hash", "name");
  console.log(exists); // 0 (means false, and if it's 1, it means true)

  await redis.hincrby("user-hash", "age", 1);
  const newAge = await redis.hget("user-hash", "age");
  console.log(newAge); // 21

  await redis.hsetnx("user-hash", "age", 23);
  console.log(await redis.hget("user-hash", "age")); // 21, as the field "age" already exists.
}

main();