Redis 命令详解与实战案例

# 设置用户会话
> SET user:1000:session "session_token" EX 3600# 1小时后过期
# 网站访问计数器
> SET visits 0
> INCR visits# 访问量+1
(integer) 1
> INCR visits
(integer) 2
# 缓存商品信息
> SET product:1234:name "iPhone 15 Pro"
> GET product:1234:name
"iPhone 15 Pro"

# 存储用户信息
> HSET user:1000 name "Alice" age 30 email "alice@example.com"
(integer) 3
# 获取用户信息
> HGET user:1000 name
"Alice"
> HGETALL user:1000
1) "name"
2) "Alice"
3) "age"
4) "30"
5) "email"
6) "alice@example.com"
# 更新用户年龄
> HINCRBY user:1000 age 1
(integer) 31

# 消息队列（生产者）
> LPUSH notifications "Order #1001 shipped"
> LPUSH notifications "User login alert"
# 消息队列（消费者）
> RPOP notifications
"Order #1001 shipped"
# 最新动态（保留最近的10条）
> LPUSH user:1000:activity "Liked post #123"
> LTRIM user:1000:activity 0 9# 只保留前10条

# 用户标签系统
> SADD user:1000:tags "sports" "music" "tech"
> SADD user:1001:tags "music" "food" "travel"
# 查找共同兴趣
> SINTER user:1000:tags user:1001:tags
1) "music"
# 内容去重
> SADD article:1234:viewers "user1000" "user1001"
> SADD article:1234:viewers "user1000"# 重复添加无效
(integer) 0

# 游戏排行榜
> ZADD leaderboard 2500 "PlayerA"
> ZADD leaderboard 3200 "PlayerB"
> ZADD leaderboard 1800 "PlayerC"
# 获取前3名
> ZREVRANGE leaderboard 0 2 WITHSCORES
1) "PlayerB"
2) "3200"
3) "PlayerA"
4) "2500"
5) "PlayerC"
6) "1800"
# 更新玩家分数
> ZADD leaderboard 3500 "PlayerB"# 更新分数

> SET session:abc123 "user_data" EX 1800# 30分钟后过期
> TTL session:abc123
(integer) 1798
> KEYS session:*# 查找所有会话键
1) "session:abc123"

> MULTI# 开始事务
> SET balance:1000 500
> DECRBY balance:1000 100# 扣款100
> INCRBY sales:2023 100# 增加销售额
> EXEC# 执行事务
1) OK
2) (integer) 400
3) (integer) 100

# 原子性更新计数器并返回新值
> EVAL "local current = redis.call('GET', KEYS[1]);
if current then
current = tonumber(current) + 1
else
current = 1
end;
redis.call('SET', KEYS[1], current);
return current" 1 page:views

# 终端1：订阅频道
> SUBSCRIBE news
# 终端2：发布消息
> PUBLISH news "Breaking: Redis 7 released!"

# 使用哈希压缩小型对象
> HSET user:1000 name "Alice" age 30
# 比多个独立键更节省内存：
# SET user:1000:name "Alice"
# SET user:1000:age 30

# 管道（Pipeline）操作
(echo -en "PING\r\nPING\r\nPING\r\n"; sleep 1) | nc localhost 6379
# 现代客户端支持（如Redis-py）
pipe = redis.pipeline()
pipe.set('key1', 'value1')
pipe.get('key2')
pipe.execute()

# 布隆过滤器防止缓存穿透
> BF.RESERVE products 0.01 1000000
> BF.ADD products "product:1234"
> BF.EXISTS products "product:5678"# 返回0表示不存在

# 获取锁（SET扩展命令）
> SET lock:order_1234 UUID NX EX 30
# 释放锁（Lua脚本保证原子性）
> EVAL "if redis.call('GET', KEYS[1]) == ARGV[1] then
return redis.call('DEL', KEYS[1])
else
return 0
end" 1 lock:order_1234 UUID

# 添加分数
> ZADD leaderboard 95 "PlayerA" 87 "PlayerB" 92 "PlayerC"
# 获取前10名
> ZREVRANGE leaderboard 0 9 WITHSCORES
# 获取玩家排名
> ZREVRANK leaderboard "PlayerB"