Redis命令及应用场景

目录

• 核心数据结构
  • string
  • list
  • set
  • zset
  • hash

核心数据结构

string

内部sds，动态扩容。小于1M加倍扩，大于1M每次扩容1M。最大长度512M。

常用命令：

SET name value
GET name
SETNX name value
EXISTS name
DEL name

# 批量
MGET name1 name2 name3
MSET name1 value1 [name2 value2 ...]

# 过期
EXPIRE name timeout
SETEX name timeout value # set+expire
SETNX name value # 不存在创建

# 计数，value是数字，不超过signed long
>SET age 30
OK
>INCR age
31
>INCRBY age 5
36
>INCRBY age -5
31
类似的还有DECR key ,DECRBY key decrement

应用场景：

1. 单值缓存
   SET key value
   GET key

2. 对象缓存
   SET user:1 value(json)
   MSET user:1:name 1880 user:2:name 2000
   MGET user:1:name user:2:name

3. 分布式锁
   SETNX product:10001 true // 1代表成功
   SETNX product:10001 false // 0代表失败
   DEL produce:10001
   SET product:10001 true ex 10 nx

4. 计数器
   INCR article:readcount:{id}
   GET article:readcount:{id}

5. Web集群session共享
   spring session + redis实现session共享

6. 分布式系统全局序列号
   INCRBY orderid 1000

list

RPUSH key val1 val2 val3
LLEN key
LPOP key
RPOP key

# 下标操作
LINDEX
LRANGE
LTRIM

set

SADD key member1 [member2]
SMEMBERS key
SISMEMBER key member
SCARD key
SPOP key

zset

ZADD key score1 member1 [score2 member2]
ZRANGE key start stop [WITHSCORES]
ZREVRANGE key start stop [WITHSCORES]
ZCARD key
ZSCORE key member
ZRANK key member
ZRANGEBYSCORE key min max [WITHSCORES] [LIMIT]
ZREM key member [member ...]

hash

HSET key field val
HGET key field
HGETALL key
HLEN key
HMSET key field1 val1 [field2 value2]
HINCRBY key field increment
HKEYS key
HLEN key

1. 对象缓存

HMSET user {userId}:name value [{userId}:name value ...]
HMGET user {userId}:name [{userId}:name ...]