Redis 哈希

Redis 哈希简介

Redis 哈希是一种记录类型，其结构为字段值对的集合。您可以使用哈希来表示基本对象以及存储计数器分组等。

Redis 命令行工具

> HSET bike:1 model Deimos brand Ergonom type 'Enduro bikes' price 4972
(integer) 4
> HGET bike:1 model
"Deimos"
> HGET bike:1 price
"4972"
> HGETALL bike:1
1) "model"
2) "Deimos"
3) "brand"
4) "Ergonom"
5) "type"
6) "Enduro bikes"
7) "price"
8) "4972"

Python

"""
Code samples for Hash doc pages:
    https://redis.github.net.cn/docs/latest/develop/data-types/hashes/
"""
import redis

r = redis.Redis(decode_responses=True)
res1 = r.hset(
    "bike:1",
    mapping={
        "model": "Deimos",
        "brand": "Ergonom",
        "type": "Enduro bikes",
        "price": 4972,
    },
)
print(res1)
# >>> 4

res2 = r.hget("bike:1", "model")
print(res2)
# >>> 'Deimos'

res3 = r.hget("bike:1", "price")
print(res3)
# >>> '4972'

res4 = r.hgetall("bike:1")
print(res4)
# >>> {'model': 'Deimos', 'brand': 'Ergonom', 'type': 'Enduro bikes', 'price': '4972'}



res5 = r.hmget("bike:1", ["model", "price"])
print(res5)
# >>> ['Deimos', '4972']


res6 = r.hincrby("bike:1", "price", 100)
print(res6)
# >>> 5072
res7 = r.hincrby("bike:1", "price", -100)
print(res7)
# >>> 4972



res11 = r.hincrby("bike:1:stats", "rides", 1)
print(res11)
# >>> 1
res12 = r.hincrby("bike:1:stats", "rides", 1)
print(res12)
# >>> 2
res13 = r.hincrby("bike:1:stats", "rides", 1)
print(res13)
# >>> 3
res14 = r.hincrby("bike:1:stats", "crashes", 1)
print(res14)
# >>> 1
res15 = r.hincrby("bike:1:stats", "owners", 1)
print(res15)
# >>> 1
res16 = r.hget("bike:1:stats", "rides")
print(res16)
# >>> 3
res17 = r.hmget("bike:1:stats", ["crashes", "owners"])
print(res17)
# >>> ['1', '1']

Node.js

import assert from 'assert';
import { createClient } from 'redis';

const client = createClient();
await client.connect();
const res1 = await client.hSet(
  'bike:1',
  {
    'model': 'Deimos',
    'brand': 'Ergonom',
    'type': 'Enduro bikes',
    'price': 4972,
  }
)
console.log(res1) // 4

const res2 = await client.hGet('bike:1', 'model')
console.log(res2)  // 'Deimos'

const res3 = await client.hGet('bike:1', 'price')
console.log(res3)  // '4972'

const res4 = await client.hGetAll('bike:1')
console.log(res4)  
/*
{
  brand: 'Ergonom',
  model: 'Deimos',
  price: '4972',
  type: 'Enduro bikes'
}
*/


const res5 = await client.hmGet('bike:1', ['model', 'price'])
console.log(res5)  // ['Deimos', '4972']


const res6 = await client.hIncrBy('bike:1', 'price', 100)
console.log(res6)  // 5072
const res7 = await client.hIncrBy('bike:1', 'price', -100)
console.log(res7)  // 4972


const res11 = await client.hIncrBy('bike:1:stats', 'rides', 1)
console.log(res11)  // 1
const res12 = await client.hIncrBy('bike:1:stats', 'rides', 1)
console.log(res12)  // 2
const res13 = await client.hIncrBy('bike:1:stats', 'rides', 1)
console.log(res13)  // 3
const res14 = await client.hIncrBy('bike:1:stats', 'crashes', 1)
console.log(res14)  // 1
const res15 = await client.hIncrBy('bike:1:stats', 'owners', 1)
console.log(res15)  // 1
const res16 = await client.hGet('bike:1:stats', 'rides')
console.log(res16)  // 3
const res17 = await client.hmGet('bike:1:stats', ['crashes', 'owners'])
console.log(res17)  // ['1', '1']

Java

package io.redis.examples;

import redis.clients.jedis.UnifiedJedis;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class HashExample {
  public void run() {
    try (UnifiedJedis jedis = new UnifiedJedis("redis://localhost:6379")) {

      Map<String, String> bike1 = new HashMap<>();
      bike1.put("model", "Deimos");
      bike1.put("brand", "Ergonom");
      bike1.put("type", "Enduro bikes");
      bike1.put("price", "4972");

      Long res1 = jedis.hset("bike:1", bike1);
      System.out.println(res1); // 4

      String res2 = jedis.hget("bike:1", "model");
      System.out.println(res2); // Deimos

      String res3 = jedis.hget("bike:1", "price");
      System.out.println(res3); // 4972

      Map<String, String> res4 = jedis.hgetAll("bike:1");
      System.out.println(res4); // {type=Enduro bikes, brand=Ergonom, price=4972, model=Deimos}


      List<String> res5 = jedis.hmget("bike:1", "model", "price");
      System.out.println(res5); // [Deimos, 4972]


      Long res6 = jedis.hincrBy("bike:1", "price", 100);
      System.out.println(res6); // 5072
      Long res7 = jedis.hincrBy("bike:1", "price", -100);
      System.out.println(res7); // 4972


      Long res8 = jedis.hincrBy("bike:1:stats", "rides", 1);
      System.out.println(res8); // 1
      Long res9 = jedis.hincrBy("bike:1:stats", "rides", 1);
      System.out.println(res9); // 2
      Long res10 = jedis.hincrBy("bike:1:stats", "rides", 1);
      System.out.println(res10); // 3
      Long res11 = jedis.hincrBy("bike:1:stats", "crashes", 1);
      System.out.println(res11); // 1
      Long res12 = jedis.hincrBy("bike:1:stats", "owners", 1);
      System.out.println(res12); // 1
      String res13 = jedis.hget("bike:1:stats", "rides");
      System.out.println(res13); // 3
      List<String> res14 = jedis.hmget("bike:1:stats", "crashes", "owners");
      System.out.println(res14); // [1, 1]

    }
  }
}


using NRedisStack.Tests;
using StackExchange.Redis;

public class HashExample
{
    [SkipIfRedis(Is.OSSCluster)]
    public void run()
    {
        var muxer = ConnectionMultiplexer.Connect("localhost:6379");
        var db = muxer.GetDatabase();
        db.KeyDelete("bike:1");
        db.HashSet("bike:1", new HashEntry[]
        {
            new HashEntry("model", "Deimos"),
            new HashEntry("brand", "Ergonom"),
            new HashEntry("type", "Enduro bikes"),
            new HashEntry("price", 4972)
        });

        Console.WriteLine("Hash Created");
        // Hash Created

        var model = db.HashGet("bike:1", "model");
        Console.WriteLine($"Model: {model}");
        // Model: Deimos

        var price = db.HashGet("bike:1", "price");
        Console.WriteLine($"Price: {price}");
        // Price: 4972

        var bike = db.HashGetAll("bike:1");
        Console.WriteLine("bike:1");
        Console.WriteLine(string.Join("\n", bike.Select(b => $"{b.Name}: {b.Value}")));
        // Bike:1:
        // model: Deimos
        // brand: Ergonom
        // type: Enduro bikes
        // price: 4972


        var values = db.HashGet("bike:1", new RedisValue[] { "model", "price" });
        Console.WriteLine(string.Join(" ", values));
        // Deimos 4972

        var newPrice = db.HashIncrement("bike:1", "price", 100);
        Console.WriteLine($"New price: {newPrice}");
        // New price: 5072

        newPrice = db.HashIncrement("bike:1", "price", -100);
        Console.WriteLine($"New price: {newPrice}");
        // New price: 4972

        var rides = db.HashIncrement("bike:1", "rides");
        Console.WriteLine($"Rides: {rides}");
        // Rides: 1

        rides = db.HashIncrement("bike:1", "rides");
        Console.WriteLine($"Rides: {rides}");
        // Rides: 2

        rides = db.HashIncrement("bike:1", "rides");
        Console.WriteLine($"Rides: {rides}");
        // Rides: 3

        var crashes = db.HashIncrement("bike:1", "crashes");
        Console.WriteLine($"Crashes: {crashes}");
        // Crashes: 1

        var owners = db.HashIncrement("bike:1", "owners");
        Console.WriteLine($"Owners: {owners}");
        // Owners: 1

        var stats = db.HashGet("bike:1", new RedisValue[] { "crashes", "owners" });
        Console.WriteLine($"Bike stats: crashes={stats[0]}, owners={stats[1]}");
        // Bike stats: crashes=1, owners=1
    }
}

虽然哈希表可以方便地表示对象，但实际上，哈希表中可放入的字段数量没有实际限制（可用内存除外），因此，您可以在应用程序内部以多种不同的方式使用哈希表。

该命令HSET设置哈希的多个字段，而HGET检索单个字段。HMGET类似HGET但返回一个值数组：

Redis 命令行工具

> HMGET bike:1 model price no-such-field
1) "Deimos"
2) "4972"
3) (nil)

Python

"""
Code samples for Hash doc pages:
    https://redis.github.net.cn/docs/latest/develop/data-types/hashes/
"""
import redis

r = redis.Redis(decode_responses=True)
res1 = r.hset(
    "bike:1",
    mapping={
        "model": "Deimos",
        "brand": "Ergonom",
        "type": "Enduro bikes",
        "price": 4972,
    },
)
print(res1)
# >>> 4

res2 = r.hget("bike:1", "model")
print(res2)
# >>> 'Deimos'

res3 = r.hget("bike:1", "price")
print(res3)
# >>> '4972'

res4 = r.hgetall("bike:1")
print(res4)
# >>> {'model': 'Deimos', 'brand': 'Ergonom', 'type': 'Enduro bikes', 'price': '4972'}



res5 = r.hmget("bike:1", ["model", "price"])
print(res5)
# >>> ['Deimos', '4972']


res6 = r.hincrby("bike:1", "price", 100)
print(res6)
# >>> 5072
res7 = r.hincrby("bike:1", "price", -100)
print(res7)
# >>> 4972



res11 = r.hincrby("bike:1:stats", "rides", 1)
print(res11)
# >>> 1
res12 = r.hincrby("bike:1:stats", "rides", 1)
print(res12)
# >>> 2
res13 = r.hincrby("bike:1:stats", "rides", 1)
print(res13)
# >>> 3
res14 = r.hincrby("bike:1:stats", "crashes", 1)
print(res14)
# >>> 1
res15 = r.hincrby("bike:1:stats", "owners", 1)
print(res15)
# >>> 1
res16 = r.hget("bike:1:stats", "rides")
print(res16)
# >>> 3
res17 = r.hmget("bike:1:stats", ["crashes", "owners"])
print(res17)
# >>> ['1', '1']

Node.js

import assert from 'assert';
import { createClient } from 'redis';

const client = createClient();
await client.connect();
const res1 = await client.hSet(
  'bike:1',
  {
    'model': 'Deimos',
    'brand': 'Ergonom',
    'type': 'Enduro bikes',
    'price': 4972,
  }
)
console.log(res1) // 4

const res2 = await client.hGet('bike:1', 'model')
console.log(res2)  // 'Deimos'

const res3 = await client.hGet('bike:1', 'price')
console.log(res3)  // '4972'

const res4 = await client.hGetAll('bike:1')
console.log(res4)  
/*
{
  brand: 'Ergonom',
  model: 'Deimos',
  price: '4972',
  type: 'Enduro bikes'
}
*/


const res5 = await client.hmGet('bike:1', ['model', 'price'])
console.log(res5)  // ['Deimos', '4972']


const res6 = await client.hIncrBy('bike:1', 'price', 100)
console.log(res6)  // 5072
const res7 = await client.hIncrBy('bike:1', 'price', -100)
console.log(res7)  // 4972


const res11 = await client.hIncrBy('bike:1:stats', 'rides', 1)
console.log(res11)  // 1
const res12 = await client.hIncrBy('bike:1:stats', 'rides', 1)
console.log(res12)  // 2
const res13 = await client.hIncrBy('bike:1:stats', 'rides', 1)
console.log(res13)  // 3
const res14 = await client.hIncrBy('bike:1:stats', 'crashes', 1)
console.log(res14)  // 1
const res15 = await client.hIncrBy('bike:1:stats', 'owners', 1)
console.log(res15)  // 1
const res16 = await client.hGet('bike:1:stats', 'rides')
console.log(res16)  // 3
const res17 = await client.hmGet('bike:1:stats', ['crashes', 'owners'])
console.log(res17)  // ['1', '1']

Java

package io.redis.examples;

import redis.clients.jedis.UnifiedJedis;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class HashExample {
  public void run() {
    try (UnifiedJedis jedis = new UnifiedJedis("redis://localhost:6379")) {

      Map<String, String> bike1 = new HashMap<>();
      bike1.put("model", "Deimos");
      bike1.put("brand", "Ergonom");
      bike1.put("type", "Enduro bikes");
      bike1.put("price", "4972");

      Long res1 = jedis.hset("bike:1", bike1);
      System.out.println(res1); // 4

      String res2 = jedis.hget("bike:1", "model");
      System.out.println(res2); // Deimos

      String res3 = jedis.hget("bike:1", "price");
      System.out.println(res3); // 4972

      Map<String, String> res4 = jedis.hgetAll("bike:1");
      System.out.println(res4); // {type=Enduro bikes, brand=Ergonom, price=4972, model=Deimos}


      List<String> res5 = jedis.hmget("bike:1", "model", "price");
      System.out.println(res5); // [Deimos, 4972]


      Long res6 = jedis.hincrBy("bike:1", "price", 100);
      System.out.println(res6); // 5072
      Long res7 = jedis.hincrBy("bike:1", "price", -100);
      System.out.println(res7); // 4972


      Long res8 = jedis.hincrBy("bike:1:stats", "rides", 1);
      System.out.println(res8); // 1
      Long res9 = jedis.hincrBy("bike:1:stats", "rides", 1);
      System.out.println(res9); // 2
      Long res10 = jedis.hincrBy("bike:1:stats", "rides", 1);
      System.out.println(res10); // 3
      Long res11 = jedis.hincrBy("bike:1:stats", "crashes", 1);
      System.out.println(res11); // 1
      Long res12 = jedis.hincrBy("bike:1:stats", "owners", 1);
      System.out.println(res12); // 1
      String res13 = jedis.hget("bike:1:stats", "rides");
      System.out.println(res13); // 3
      List<String> res14 = jedis.hmget("bike:1:stats", "crashes", "owners");
      System.out.println(res14); // [1, 1]

    }
  }
}


using NRedisStack.Tests;
using StackExchange.Redis;

public class HashExample
{
    [SkipIfRedis(Is.OSSCluster)]
    public void run()
    {
        var muxer = ConnectionMultiplexer.Connect("localhost:6379");
        var db = muxer.GetDatabase();
        db.KeyDelete("bike:1");
        db.HashSet("bike:1", new HashEntry[]
        {
            new HashEntry("model", "Deimos"),
            new HashEntry("brand", "Ergonom"),
            new HashEntry("type", "Enduro bikes"),
            new HashEntry("price", 4972)
        });

        Console.WriteLine("Hash Created");
        // Hash Created

        var model = db.HashGet("bike:1", "model");
        Console.WriteLine($"Model: {model}");
        // Model: Deimos

        var price = db.HashGet("bike:1", "price");
        Console.WriteLine($"Price: {price}");
        // Price: 4972

        var bike = db.HashGetAll("bike:1");
        Console.WriteLine("bike:1");
        Console.WriteLine(string.Join("\n", bike.Select(b => $"{b.Name}: {b.Value}")));
        // Bike:1:
        // model: Deimos
        // brand: Ergonom
        // type: Enduro bikes
        // price: 4972


        var values = db.HashGet("bike:1", new RedisValue[] { "model", "price" });
        Console.WriteLine(string.Join(" ", values));
        // Deimos 4972

        var newPrice = db.HashIncrement("bike:1", "price", 100);
        Console.WriteLine($"New price: {newPrice}");
        // New price: 5072

        newPrice = db.HashIncrement("bike:1", "price", -100);
        Console.WriteLine($"New price: {newPrice}");
        // New price: 4972

        var rides = db.HashIncrement("bike:1", "rides");
        Console.WriteLine($"Rides: {rides}");
        // Rides: 1

        rides = db.HashIncrement("bike:1", "rides");
        Console.WriteLine($"Rides: {rides}");
        // Rides: 2

        rides = db.HashIncrement("bike:1", "rides");
        Console.WriteLine($"Rides: {rides}");
        // Rides: 3

        var crashes = db.HashIncrement("bike:1", "crashes");
        Console.WriteLine($"Crashes: {crashes}");
        // Crashes: 1

        var owners = db.HashIncrement("bike:1", "owners");
        Console.WriteLine($"Owners: {owners}");
        // Owners: 1

        var stats = db.HashGet("bike:1", new RedisValue[] { "crashes", "owners" });
        Console.WriteLine($"Bike stats: crashes={stats[0]}, owners={stats[1]}");
        // Bike stats: crashes=1, owners=1
    }
}

还有一些命令可以对单个字段执行操作，例如HINCRBY：

Redis 命令行工具

> HINCRBY bike:1 price 100
(integer) 5072
> HINCRBY bike:1 price -100
(integer) 4972

Python

"""
Code samples for Hash doc pages:
    https://redis.github.net.cn/docs/latest/develop/data-types/hashes/
"""
import redis

r = redis.Redis(decode_responses=True)
res1 = r.hset(
    "bike:1",
    mapping={
        "model": "Deimos",
        "brand": "Ergonom",
        "type": "Enduro bikes",
        "price": 4972,
    },
)
print(res1)
# >>> 4

res2 = r.hget("bike:1", "model")
print(res2)
# >>> 'Deimos'

res3 = r.hget("bike:1", "price")
print(res3)
# >>> '4972'

res4 = r.hgetall("bike:1")
print(res4)
# >>> {'model': 'Deimos', 'brand': 'Ergonom', 'type': 'Enduro bikes', 'price': '4972'}



res5 = r.hmget("bike:1", ["model", "price"])
print(res5)
# >>> ['Deimos', '4972']


res6 = r.hincrby("bike:1", "price", 100)
print(res6)
# >>> 5072
res7 = r.hincrby("bike:1", "price", -100)
print(res7)
# >>> 4972



res11 = r.hincrby("bike:1:stats", "rides", 1)
print(res11)
# >>> 1
res12 = r.hincrby("bike:1:stats", "rides", 1)
print(res12)
# >>> 2
res13 = r.hincrby("bike:1:stats", "rides", 1)
print(res13)
# >>> 3
res14 = r.hincrby("bike:1:stats", "crashes", 1)
print(res14)
# >>> 1
res15 = r.hincrby("bike:1:stats", "owners", 1)
print(res15)
# >>> 1
res16 = r.hget("bike:1:stats", "rides")
print(res16)
# >>> 3
res17 = r.hmget("bike:1:stats", ["crashes", "owners"])
print(res17)
# >>> ['1', '1']

Node.js

import assert from 'assert';
import { createClient } from 'redis';

const client = createClient();
await client.connect();
const res1 = await client.hSet(
  'bike:1',
  {
    'model': 'Deimos',
    'brand': 'Ergonom',
    'type': 'Enduro bikes',
    'price': 4972,
  }
)
console.log(res1) // 4

const res2 = await client.hGet('bike:1', 'model')
console.log(res2)  // 'Deimos'

const res3 = await client.hGet('bike:1', 'price')
console.log(res3)  // '4972'

const res4 = await client.hGetAll('bike:1')
console.log(res4)  
/*
{
  brand: 'Ergonom',
  model: 'Deimos',
  price: '4972',
  type: 'Enduro bikes'
}
*/


const res5 = await client.hmGet('bike:1', ['model', 'price'])
console.log(res5)  // ['Deimos', '4972']


const res6 = await client.hIncrBy('bike:1', 'price', 100)
console.log(res6)  // 5072
const res7 = await client.hIncrBy('bike:1', 'price', -100)
console.log(res7)  // 4972


const res11 = await client.hIncrBy('bike:1:stats', 'rides', 1)
console.log(res11)  // 1
const res12 = await client.hIncrBy('bike:1:stats', 'rides', 1)
console.log(res12)  // 2
const res13 = await client.hIncrBy('bike:1:stats', 'rides', 1)
console.log(res13)  // 3
const res14 = await client.hIncrBy('bike:1:stats', 'crashes', 1)
console.log(res14)  // 1
const res15 = await client.hIncrBy('bike:1:stats', 'owners', 1)
console.log(res15)  // 1
const res16 = await client.hGet('bike:1:stats', 'rides')
console.log(res16)  // 3
const res17 = await client.hmGet('bike:1:stats', ['crashes', 'owners'])
console.log(res17)  // ['1', '1']

Java

package io.redis.examples;

import redis.clients.jedis.UnifiedJedis;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class HashExample {
  public void run() {
    try (UnifiedJedis jedis = new UnifiedJedis("redis://localhost:6379")) {

      Map<String, String> bike1 = new HashMap<>();
      bike1.put("model", "Deimos");
      bike1.put("brand", "Ergonom");
      bike1.put("type", "Enduro bikes");
      bike1.put("price", "4972");

      Long res1 = jedis.hset("bike:1", bike1);
      System.out.println(res1); // 4

      String res2 = jedis.hget("bike:1", "model");
      System.out.println(res2); // Deimos

      String res3 = jedis.hget("bike:1", "price");
      System.out.println(res3); // 4972

      Map<String, String> res4 = jedis.hgetAll("bike:1");
      System.out.println(res4); // {type=Enduro bikes, brand=Ergonom, price=4972, model=Deimos}


      List<String> res5 = jedis.hmget("bike:1", "model", "price");
      System.out.println(res5); // [Deimos, 4972]


      Long res6 = jedis.hincrBy("bike:1", "price", 100);
      System.out.println(res6); // 5072
      Long res7 = jedis.hincrBy("bike:1", "price", -100);
      System.out.println(res7); // 4972


      Long res8 = jedis.hincrBy("bike:1:stats", "rides", 1);
      System.out.println(res8); // 1
      Long res9 = jedis.hincrBy("bike:1:stats", "rides", 1);
      System.out.println(res9); // 2
      Long res10 = jedis.hincrBy("bike:1:stats", "rides", 1);
      System.out.println(res10); // 3
      Long res11 = jedis.hincrBy("bike:1:stats", "crashes", 1);
      System.out.println(res11); // 1
      Long res12 = jedis.hincrBy("bike:1:stats", "owners", 1);
      System.out.println(res12); // 1
      String res13 = jedis.hget("bike:1:stats", "rides");
      System.out.println(res13); // 3
      List<String> res14 = jedis.hmget("bike:1:stats", "crashes", "owners");
      System.out.println(res14); // [1, 1]

    }
  }
}


using NRedisStack.Tests;
using StackExchange.Redis;

public class HashExample
{
    [SkipIfRedis(Is.OSSCluster)]
    public void run()
    {
        var muxer = ConnectionMultiplexer.Connect("localhost:6379");
        var db = muxer.GetDatabase();
        db.KeyDelete("bike:1");
        db.HashSet("bike:1", new HashEntry[]
        {
            new HashEntry("model", "Deimos"),
            new HashEntry("brand", "Ergonom"),
            new HashEntry("type", "Enduro bikes"),
            new HashEntry("price", 4972)
        });

        Console.WriteLine("Hash Created");
        // Hash Created

        var model = db.HashGet("bike:1", "model");
        Console.WriteLine($"Model: {model}");
        // Model: Deimos

        var price = db.HashGet("bike:1", "price");
        Console.WriteLine($"Price: {price}");
        // Price: 4972

        var bike = db.HashGetAll("bike:1");
        Console.WriteLine("bike:1");
        Console.WriteLine(string.Join("\n", bike.Select(b => $"{b.Name}: {b.Value}")));
        // Bike:1:
        // model: Deimos
        // brand: Ergonom
        // type: Enduro bikes
        // price: 4972


        var values = db.HashGet("bike:1", new RedisValue[] { "model", "price" });
        Console.WriteLine(string.Join(" ", values));
        // Deimos 4972

        var newPrice = db.HashIncrement("bike:1", "price", 100);
        Console.WriteLine($"New price: {newPrice}");
        // New price: 5072

        newPrice = db.HashIncrement("bike:1", "price", -100);
        Console.WriteLine($"New price: {newPrice}");
        // New price: 4972

        var rides = db.HashIncrement("bike:1", "rides");
        Console.WriteLine($"Rides: {rides}");
        // Rides: 1

        rides = db.HashIncrement("bike:1", "rides");
        Console.WriteLine($"Rides: {rides}");
        // Rides: 2

        rides = db.HashIncrement("bike:1", "rides");
        Console.WriteLine($"Rides: {rides}");
        // Rides: 3

        var crashes = db.HashIncrement("bike:1", "crashes");
        Console.WriteLine($"Crashes: {crashes}");
        // Crashes: 1

        var owners = db.HashIncrement("bike:1", "owners");
        Console.WriteLine($"Owners: {owners}");
        // Owners: 1

        var stats = db.HashGet("bike:1", new RedisValue[] { "crashes", "owners" });
        Console.WriteLine($"Bike stats: crashes={stats[0]}, owners={stats[1]}");
        // Bike stats: crashes=1, owners=1
    }
}

您可以在文档中找到哈希命令的完整列表。

值得注意的是，小哈希值（即少数具有小值的元素）以特殊方式在内存中编码，这使得它们的内存效率非常高。

基本命令

HSET：设置哈希表中一个或多个字段的值。
HGET：返回给定字段的值。
HMGET：返回一个或多个给定字段的值。
HINCRBY：将给定字段的值增加提供的整数。

查看哈希命令的完整列表。

示例

存储自行车：1 被骑行、撞车或更换主人的次数的计数器：

Redis 命令行工具

> HINCRBY bike:1:stats rides 1
(integer) 1
> HINCRBY bike:1:stats rides 1
(integer) 2
> HINCRBY bike:1:stats rides 1
(integer) 3
> HINCRBY bike:1:stats crashes 1
(integer) 1
> HINCRBY bike:1:stats owners 1
(integer) 1
> HGET bike:1:stats rides
"3"
> HMGET bike:1:stats owners crashes
1) "1"
2) "1"

Python

"""
Code samples for Hash doc pages:
    https://redis.github.net.cn/docs/latest/develop/data-types/hashes/
"""
import redis

r = redis.Redis(decode_responses=True)
res1 = r.hset(
    "bike:1",
    mapping={
        "model": "Deimos",
        "brand": "Ergonom",
        "type": "Enduro bikes",
        "price": 4972,
    },
)
print(res1)
# >>> 4

res2 = r.hget("bike:1", "model")
print(res2)
# >>> 'Deimos'

res3 = r.hget("bike:1", "price")
print(res3)
# >>> '4972'

res4 = r.hgetall("bike:1")
print(res4)
# >>> {'model': 'Deimos', 'brand': 'Ergonom', 'type': 'Enduro bikes', 'price': '4972'}



res5 = r.hmget("bike:1", ["model", "price"])
print(res5)
# >>> ['Deimos', '4972']


res6 = r.hincrby("bike:1", "price", 100)
print(res6)
# >>> 5072
res7 = r.hincrby("bike:1", "price", -100)
print(res7)
# >>> 4972



res11 = r.hincrby("bike:1:stats", "rides", 1)
print(res11)
# >>> 1
res12 = r.hincrby("bike:1:stats", "rides", 1)
print(res12)
# >>> 2
res13 = r.hincrby("bike:1:stats", "rides", 1)
print(res13)
# >>> 3
res14 = r.hincrby("bike:1:stats", "crashes", 1)
print(res14)
# >>> 1
res15 = r.hincrby("bike:1:stats", "owners", 1)
print(res15)
# >>> 1
res16 = r.hget("bike:1:stats", "rides")
print(res16)
# >>> 3
res17 = r.hmget("bike:1:stats", ["crashes", "owners"])
print(res17)
# >>> ['1', '1']

Node.js

import assert from 'assert';
import { createClient } from 'redis';

const client = createClient();
await client.connect();
const res1 = await client.hSet(
  'bike:1',
  {
    'model': 'Deimos',
    'brand': 'Ergonom',
    'type': 'Enduro bikes',
    'price': 4972,
  }
)
console.log(res1) // 4

const res2 = await client.hGet('bike:1', 'model')
console.log(res2)  // 'Deimos'

const res3 = await client.hGet('bike:1', 'price')
console.log(res3)  // '4972'

const res4 = await client.hGetAll('bike:1')
console.log(res4)  
/*
{
  brand: 'Ergonom',
  model: 'Deimos',
  price: '4972',
  type: 'Enduro bikes'
}
*/


const res5 = await client.hmGet('bike:1', ['model', 'price'])
console.log(res5)  // ['Deimos', '4972']


const res6 = await client.hIncrBy('bike:1', 'price', 100)
console.log(res6)  // 5072
const res7 = await client.hIncrBy('bike:1', 'price', -100)
console.log(res7)  // 4972


const res11 = await client.hIncrBy('bike:1:stats', 'rides', 1)
console.log(res11)  // 1
const res12 = await client.hIncrBy('bike:1:stats', 'rides', 1)
console.log(res12)  // 2
const res13 = await client.hIncrBy('bike:1:stats', 'rides', 1)
console.log(res13)  // 3
const res14 = await client.hIncrBy('bike:1:stats', 'crashes', 1)
console.log(res14)  // 1
const res15 = await client.hIncrBy('bike:1:stats', 'owners', 1)
console.log(res15)  // 1
const res16 = await client.hGet('bike:1:stats', 'rides')
console.log(res16)  // 3
const res17 = await client.hmGet('bike:1:stats', ['crashes', 'owners'])
console.log(res17)  // ['1', '1']

Java

package io.redis.examples;

import redis.clients.jedis.UnifiedJedis;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class HashExample {
  public void run() {
    try (UnifiedJedis jedis = new UnifiedJedis("redis://localhost:6379")) {

      Map<String, String> bike1 = new HashMap<>();
      bike1.put("model", "Deimos");
      bike1.put("brand", "Ergonom");
      bike1.put("type", "Enduro bikes");
      bike1.put("price", "4972");

      Long res1 = jedis.hset("bike:1", bike1);
      System.out.println(res1); // 4

      String res2 = jedis.hget("bike:1", "model");
      System.out.println(res2); // Deimos

      String res3 = jedis.hget("bike:1", "price");
      System.out.println(res3); // 4972

      Map<String, String> res4 = jedis.hgetAll("bike:1");
      System.out.println(res4); // {type=Enduro bikes, brand=Ergonom, price=4972, model=Deimos}


      List<String> res5 = jedis.hmget("bike:1", "model", "price");
      System.out.println(res5); // [Deimos, 4972]


      Long res6 = jedis.hincrBy("bike:1", "price", 100);
      System.out.println(res6); // 5072
      Long res7 = jedis.hincrBy("bike:1", "price", -100);
      System.out.println(res7); // 4972


      Long res8 = jedis.hincrBy("bike:1:stats", "rides", 1);
      System.out.println(res8); // 1
      Long res9 = jedis.hincrBy("bike:1:stats", "rides", 1);
      System.out.println(res9); // 2
      Long res10 = jedis.hincrBy("bike:1:stats", "rides", 1);
      System.out.println(res10); // 3
      Long res11 = jedis.hincrBy("bike:1:stats", "crashes", 1);
      System.out.println(res11); // 1
      Long res12 = jedis.hincrBy("bike:1:stats", "owners", 1);
      System.out.println(res12); // 1
      String res13 = jedis.hget("bike:1:stats", "rides");
      System.out.println(res13); // 3
      List<String> res14 = jedis.hmget("bike:1:stats", "crashes", "owners");
      System.out.println(res14); // [1, 1]

    }
  }
}


using NRedisStack.Tests;
using StackExchange.Redis;

public class HashExample
{
    [SkipIfRedis(Is.OSSCluster)]
    public void run()
    {
        var muxer = ConnectionMultiplexer.Connect("localhost:6379");
        var db = muxer.GetDatabase();
        db.KeyDelete("bike:1");
        db.HashSet("bike:1", new HashEntry[]
        {
            new HashEntry("model", "Deimos"),
            new HashEntry("brand", "Ergonom"),
            new HashEntry("type", "Enduro bikes"),
            new HashEntry("price", 4972)
        });

        Console.WriteLine("Hash Created");
        // Hash Created

        var model = db.HashGet("bike:1", "model");
        Console.WriteLine($"Model: {model}");
        // Model: Deimos

        var price = db.HashGet("bike:1", "price");
        Console.WriteLine($"Price: {price}");
        // Price: 4972

        var bike = db.HashGetAll("bike:1");
        Console.WriteLine("bike:1");
        Console.WriteLine(string.Join("\n", bike.Select(b => $"{b.Name}: {b.Value}")));
        // Bike:1:
        // model: Deimos
        // brand: Ergonom
        // type: Enduro bikes
        // price: 4972


        var values = db.HashGet("bike:1", new RedisValue[] { "model", "price" });
        Console.WriteLine(string.Join(" ", values));
        // Deimos 4972

        var newPrice = db.HashIncrement("bike:1", "price", 100);
        Console.WriteLine($"New price: {newPrice}");
        // New price: 5072

        newPrice = db.HashIncrement("bike:1", "price", -100);
        Console.WriteLine($"New price: {newPrice}");
        // New price: 4972

        var rides = db.HashIncrement("bike:1", "rides");
        Console.WriteLine($"Rides: {rides}");
        // Rides: 1

        rides = db.HashIncrement("bike:1", "rides");
        Console.WriteLine($"Rides: {rides}");
        // Rides: 2

        rides = db.HashIncrement("bike:1", "rides");
        Console.WriteLine($"Rides: {rides}");
        // Rides: 3

        var crashes = db.HashIncrement("bike:1", "crashes");
        Console.WriteLine($"Crashes: {crashes}");
        // Crashes: 1

        var owners = db.HashIncrement("bike:1", "owners");
        Console.WriteLine($"Owners: {owners}");
        // Owners: 1

        var stats = db.HashGet("bike:1", new RedisValue[] { "crashes", "owners" });
        Console.WriteLine($"Bike stats: crashes={stats[0]}, owners={stats[1]}");
        // Bike stats: crashes=1, owners=1
    }
}

字段过期

Redis Community Edition 7.4 中的新功能是能够为各个哈希字段指定过期时间或生存时间 (TTL) 值。此功能与密钥过期功能类似，并且包含许多类似的命令。

使用以下命令为特定字段设置确切的到期时间或 TTL 值：

HEXPIRE：设置剩余TTL（秒数）。
HPEXPIRE：设置剩余TTL，单位为毫秒。
HEXPIREAT：将过期时间设置为以秒为单位指定的时间戳¹。
HPEXPIREAT：将过期时间设置为以毫秒为单位指定的时间戳。

使用以下命令检索特定字段过期的确切时间或剩余 TTL：

HEXPIRETIME：以秒为单位的时间戳形式获取到期时间。
HPEXPIRETIME：以毫秒为单位的时间戳形式获取到期时间。
HTTL：获取剩余TTL，单位为秒。
HPTTL：获取剩余的TTL，单位为毫秒。

使用以下命令删除特定字段的过期时间：

HPERSIST：删除有效期。

常见字段过期用例

事件跟踪：使用哈希键存储过去一小时的事件。将每个事件的 TTL 设置为一小时。用于HLEN统计过去一小时的事件。
欺诈检测：创建一个包含事件每小时计数器的哈希。将每个字段的 TTL 设置为 48 小时。查询哈希以获取过去 48 小时内每小时的事件数。
客户会话管理：将客户数据存储在哈希键中。为每个会话创建一个新的哈希键，并将会话字段添加到客户的哈希键中。会话过期时，会话键和客户哈希键中的会话字段都会自动过期。
活动会话跟踪：将所有活动会话存储在哈希键中。将每个会话的 TTL 设置为在不活动后自动过期。用于HLEN计算活动会话。

字段过期示例

官方客户端库尚不支持哈希字段过期，但您现在可以使用Python（redis-py）和Java（Jedis）客户端库的测试版本来测试哈希字段过期。

以下是一些 Python 示例，演示如何使用字段过期。

考虑一个用于存储传感器数据的哈希数据集，其结构如下：

event = {
    'air_quality': 256,
    'Battery_level':89
}

client.hset('sensor:sensor1', mapping=event)

设置并检索哈希中多个字段的 TTL：

# set the TTL for two hash fields to 60 seconds
client.hexpire('sensor:sensor1', 60, 'air_quality', 'battery_level')
ttl = client.httl('sensor:sensor1', 'air_quality', 'battery_level')
print(ttl)
# prints [60]

以毫秒为单位设置和检索哈希字段的 TTL：

# set the TTL of the 'air_quality' field in milliseconds
client.hpexpire('sensor:sensor1', 60000, 'air_quality')
# and retrieve it
pttl = client.hpttl('sensor:sensor1', 'air_quality')
print(pttl)
# prints [60000]

设置并检索哈希字段的过期时间戳：

# set the expiration of 'air_quality' to now + 24 hours
# (similar to setting the TTL to 24 hours)
client.hexpireat('sensor:sensor1', 
    datetime.now() + timedelta(hours=24), 
    'air_quality')
# and retrieve it
expire_time = client.hexpiretime('sensor:sensor1', 'air_quality')
print(expire_time)
# prints [1717668041]

表现

大多数 Redis 哈希命令都是 O(1)。

一些命令（例如HKEYS、、HVALS）HGETALL以及大多数与到期相关的命令都是 O(n)，其中n是字段值对的数量。

限制

每个哈希最多可以存储 4,294,967,295 (2^32 - 1) 个字段值对。实际上，您的哈希仅受托管 Redis 部署的虚拟机上的总内存限制。

了解更多

Redis Hashes Explained是一个简短、全面的视频解释器，涵盖了 Redis 哈希。
Redis University 的 RU101详细介绍了 Redis 哈希。

所有时间戳均以Unix 纪元以来的秒或毫秒为单位指定。↩︎

Redis 哈希

基本命令

示例

字段过期

常见字段过期用例

字段过期示例

表现

限制

了解更多

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