Redis数据类型之哈希命令

痛定思痛。 2021-07-25 01:39 447阅读 0赞

**一 点睛**

Hash类型用于存储结构化数据。

Hash可以看作是Map中的Map。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70][]

**二 实战**

1 HSET命令：为哈希的域设值

127.0.0.1:6379> HSET student1 stuName 'liuhefei'
    1
    127.0.0.1:6379> HSET student1 stuID 20190102
    1
    127.0.0.1:6379> HSET student1 age 22
    1
    127.0.0.1:6379> HSET student1 sex 'nan'
    1
    127.0.0.1:6379> HSET student1 height 171
    1
    127.0.0.1:6379> HSET student1 weight 75
    1
    127.0.0.1:6379> HSET student1 birthday 1996-02-14
    1
    127.0.0.1:6379> HSET student1 className 'ruanjian1ban'
    1

2 HSETNX命令：为哈希表不存在的域设值

127.0.0.1:6379> HSETNX student1 motto 'pinggenisiwohuo'
    1
    127.0.0.1:6379> HSETNX student1 motto 'pinggechuxiaqiudong'
    0

3 HMSET命令：设置多个域和值到哈希表中

127.0.0.1:6379> HMSET student2 stuName 'xiaowang' stuID 20180920 age 24 sex 'nan' height 174 weight 71
    OK

4 HGET命令：获取哈希表中域的值

127.0.0.1:6379> HGET student1 stuName
    liuhefei
    127.0.0.1:6379> HGET student1 stuID
    20190102
    127.0.0.1:6379> HGET student1 age
    22
    127.0.0.1:6379> HGET student1 sex
    nan
    127.0.0.1:6379> HGET student1 height
    171
    127.0.0.1:6379> HGET student1 weight
    75
    127.0.0.1:6379> HGET student1 birthday
    1996-02-14
    127.0.0.1:6379> HGET student1 className
    ruanjian1ban

5 HGETALL命令：获取哈希表中所有的域和值

127.0.0.1:6379> HGETALL student2
    stuName
    xiaowang
    stuID
    20180920
    age
    24
    sex
    nan
    height
    174
    weight
    71

6 HMGET命令：获取多个域的值

127.0.0.1:6379> HMGET student1 stuName stuID age birthday className
    liuhefei
    20190102
    22
    1996-02-14
    ruanjian1ban

7 HKEYS命令：获取哈希表中所有域

127.0.0.1:6379> HKEYS student1
    stuName
    stuID
    age
    sex
    height
    weight
    birthday
    className
    motto

8 HVALS命令：获取哈希表中所有域的值

127.0.0.1:6379> HVALS student1
    liuhefei
    20190102
    22
    nan
    171
    75
    1996-02-14
    ruanjian1ban
    pinggenisiwohuo

9 HLEN命令：统计哈希表中域的数量

127.0.0.1:6379> HKEYS student2
    stuName
    stuID
    age
    sex
    height
    weight
    127.0.0.1:6379> HLEN student2
    6

10 HSTRLEN：统计域的值的字符串长度

127.0.0.1:6379> HSTRLEN student1 stuName
    8
    127.0.0.1:6379> HSTRLEN student1 stuID
    8
    127.0.0.1:6379> HSTRLEN student1 className
    12
    127.0.0.1:6379> HSTRLEN student1 motto
    15
    127.0.0.1:6379> HSTRLEN student className
    0

11 HINCRBY命令：为哈希表中的域加上增量值

127.0.0.1:6379> HINCRBY student1 age 3
    25
    127.0.0.1:6379> HINCRBY student1 height 3
    174
    127.0.0.1:6379> HINCRBY student1 weight 3
    78
    127.0.0.1:6379> HINCRBY student1 className 3
    ERR hash value is not an integer

12 HINCRBYFLOAT命令：为哈希表中的域加上浮点数增量值

127.0.0.1:6379> HINCRBYFLOAT student2 height 3.56
    177.56
    127.0.0.1:6379> HINCRBYFLOAT student2 weight 4.43
    75.430000000000007
    127.0.0.1:6379> HINCRBYFLOAT student2 className 2.54
    2.54

13 HDEL命令：删除哈希表中的多个域

127.0.0.1:6379> HDEL student2 height weight
    2
    127.0.0.1:6379> HDEL student2 height weight
    0

14 HEXISTS命令：判断哈希表中的域是否存在

127.0.0.1:6379> HEXISTS student1 stuName
    1
    127.0.0.1:6379> HEXISTS student1 age
    1
    127.0.0.1:6379> HEXISTS student1 height
    1
    127.0.0.1:6379> HEXISTS student3 className
    0

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