Redis 之（二） Redis的基本数据结构以及一些常用的操作

> set name codehole  //设置指定key的值
OK
> get name  //获取指定key
"codehole"
> exists name
(integer) 1
> del name
(integer) 1
> get name
(nil)

> set name1 codehole
OK
> set name2 holycoder
OK
> mget name1 name2 name3 # 返回一个列表
1) "codehole"
2) "holycoder"
3) (nil)
> mset name1 boy name2 girl name3 unknown
> mget name1 name2 name3
1) "boy"
2) "girl"
3) "unknown"...

> set name c1
OK
> get name
"c1"
> expire name 5  //设置五秒后过期
(integer) 1
//.....等待五秒
> get name
(nil)

> setex name 5 c1  //5s 后过期，等价于 set+expire
> get name
"c1"
//.....等待五秒
> get name
(nil)

> setnx name c1  // 如果 name 不存在就执行 set 创建
(integer) 1
> get name
"c1"
> setnx name c2
(integer) 0  // 因为 name 已经存在，所以 set 创建不成功
> get name
"c1"  // 没有改变...

> set age 30
OK
> incr age //通过incr命令将key中存储的数值增一，如果key不存在，key的值会被先初始化为0，然后再进行INCR操作
(integer) 31
> incrby age 5 //通过incrby命令将key中存储的数值加上指定的增加量，如果key不存在，key的值会被先初始化为0，然后再进行INCR操作
(integer) 36
> incrby age -5
(integer) 31
> set c1 9223372036854775807  // Long.Max
OK
> incr c1
(error) ERR increment or decrement would overflow...

> rpush book java
(integer) 1
> rpush book python
(integer) 2
> rpush book golong
(integer) 3//   将一个或多个值 value 插入到列表 key 的表尾(最右边)
//   也可写为 
//   > rpush books python java golang
> llen book//返回列表的长度
(integer) 3
> lpop book
"java"
> lpop book
"python"
> lpop book//移除列表左侧的头元素
"golong"

> rpush book python java golang
(integer) 3
> rpop book
"golang"
> rpop book
"java"
> rpop book
"python"
> rpop book
(nil)...

redis> LPUSH mylist "World"
(integer) 1

redis> LPUSH mylist "Hello"
(integer) 2

redis> LINDEX mylist 0
"Hello"

redis> LINDEX mylist -1
"World"

redis> LINDEX mylist 3       //index不在 mylist 的区间范围内
(nil)

> RPUSH mylist "hello"
(integer) 1
> RPUSH mylist "hello"
(integer) 2
> RPUSH mylist "foo"
(integer) 3
> RPUSH mylist "bar"
(integer) 4
> LTRIM mylist 1 -1
OK
> LRANGE mylist 0 -1
1) "hello"
2) "foo"
3) "bar"

> hset books java "think in java"  //命令行的字符串如果包含空格，要用引号括起来。。。hset 字典名 键 值
(integer) 1
> hset books golang "concurrency in go"
(integer) 1
> hset books python "python cookbook"
(integer) 1
> hgetall books  //entries()，key 和 value 间隔出现
1) "java"
2) "think in java"
3) "golang"
4) "concurrency in go"
5) "python"
6) "python cookbook"
> hlen books
(integer) 3
> hget books java
"think in java"
> hset books golang "learning go programming"  //因为是更新操作，所以返回 0
(integer) 0
> hget books golang
"learning go programming"
> hmset books java "effective java" python "learning python" golang "modern golang programming"  // 批量 set
OK...

HSET myhash field 5 (integer) 1 HINCRBY myhash field 1 (integer) 6 HINCRBY myhash field -1 (integer) 5 HINCRBY myhash field -10 (integer) -5

> sadd books python
(integer) 1
> sadd books python  #  重复
(integer) 0
> sadd books java golang
(integer) 2
> smembers books  // 注意顺序，和插入的并不一致，因为 set 是无序的
1) "java"
2) "python"
3) "golang"
> sismember books java  // 查询某个 value 是否存在，相当于 contains(o)
(integer) 1
> sismember books rust
(integer) 0
> scard books  // 获取长度相当于 count()
(integer) 3
> spop books  // 弹出一个
"java"...

> zadd books 9.0 "think in java"
(integer) 1
> zadd books 8.9 "java concurrency"
(integer) 1
> zadd books 8.6 "java cookbook"
(integer) 1
> zrange books 0 -1  // 按 score 排序列出，0表示第一个成员，-1表示倒数第一个成员
1) "java cookbook"
2) "java concurrency"
3) "think in java"
> zrevrange books 0 -1  // 按 score 逆序列出，参数区间为排名范围
1) "think in java"
2) "java concurrency"
3) "java cookbook"
> zcard books // 统计这个列表中元素的个数
(integer) 3
> zscore books "java concurrency"  // 获取指定 value 的 score
"8.9000000000000004"  // 内部 score 使用 double 类型进行存储，所以存在小数点精度问题
> zrank books "java concurrency"  // 排名
(integer) 1
> zrangebyscore books 0 8.91  //根据分值区间遍历 zset
1) "java cookbook"
2) "java concurrency"
> zrangebyscore books -inf 8.91 withscores // 根据分值区间 (-∞, 8.91] 遍历 zset，同时返回分值。inf 代表 infinite，无穷大的意思。
1) "java cookbook"
2) "8.5999999999999996"
3) "java concurrency"
4) "8.9000000000000004"
> zrem books "java concurrency"  // 删除 value
(integer) 1
> zrange books 0 -1
1) "java cookbook"
2) "think in java"...