redis五种数据结构及常用命令

String

>set a 1
"OK"  
>get a
"1"  
>del a
"1"
>get a
null

LIST

//向list放入元素
>rpush list-key item
"1"
>rpush list-key item1
"2"
>rpush list-key item2
"3"
>rpush list-key item
"4"

//查询list所有元素
>lrange list-key 0 -1
 1)  "item"
 2)  "item1"
 3)  "item2"
 4)  "item"
 
 //查询list指定元素
 >lindex list-key 1
 "item1"
 
 //从头部弹出元素(先进先出)
 >lpop list-key
 "item"
 >lpop list-key
 "item"

SET

//向set放入元素(不可重复)
>sadd set-key item
"1"
>sadd set-key item1
"1"
>sadd set-key item2
"1"
>sadd set-key item
"0"

//查询set中所有元素
>smembers set-key
 1)  "item"
 2)  "item1"
 3)  "item2"
 
 //查询set中是否存在指定元素
>sismember set-key item
"1"

//删除set指定元素
>srem set-key item2
"1"

HASH

//向hash中放入元素（key相同覆盖）
>hset hash-key sub-key1 value1
"1"
>hset hash-key sub-key2 value2
"1"
>hset hash-key sub-key1 value1
"0"

//查询hash所有键值对
>hgetall hash-key
 1)  "sub-key1"
 2)  "value1"
 3)  "sub-key2"
 4)  "value2"

//获取指定key的值 
>hget hash-key sub-key1
"value1"

//删除指定的key的键值对
>hdel hash-key sub-key1
"1"
//必须指定key
>hdel hash-key
"ERR wrong number of arguments for 'hdel' command"

ZSET

//放入键值对（前面为值（float），后面为key）
>zadd zset-key 1 member1
"1"
>zadd zset-key 2 member2
"1"

//查询所有键值对，默认按值升序,不加withscores只显示key
>zrange zset-key 0 -1 withscores
 1)  "member1"
 2)  "1"
 3)  "member2"
 4)  "2"
 
//移除指定key的元素
>zrem zset-key member1
"1"

HyperLogLog

//超级厉害的数据结构
>pfadd alist a b c d 1 2 3 4 a c 1
"1"

//基数聚合统计，误差率0.83左右
>pfcount alist
 "8"