Redis hash类型

Redis hash类型是键值对的集合类型。经常被用来做对象的映射。

Redis hash命令

hash格式如下 hash_key_name field value field value 。 field必须和value成对出现。

hset命令

hset命令用来创建hash对象，或者修改hash中field对应的value.如果key不存在，则创建该key对应的hash对象，返回新增的field值。如果hash中对应的field存在则修改对应的值，返回0。

127.0.0.1:6379> help hset

  HSET key field value [field value ...]
  summary: Set the string value of a hash field
  since: 2.0.0
  group: hash

127.0.0.1:6379> hset user:1 name zhangsan age 42
(integer) 2
127.0.0.1:6379> hset user:2 name lisi  age 28
(integer) 2
127.0.0.1:6379> hset user:1 name wangwu age 50
(integer) 0
127.0.0.1:6379> hset user:1 name wangwu age 50 sex m
(integer) 1

hget命令

hget命令用来获取hash中field对应的value。如果hash中field不存在或者hash不存在则返回nil。

127.0.0.1:6379> hget user:1 agea
(nil)
127.0.0.1:6379> help hget

  HGET key field
  summary: Get the value of a hash field
  since: 2.0.0
  group: hash

127.0.0.1:6379> hset user:1 name wangwu age 50 sex m
(integer) 1
127.0.0.1:6379> hget user:1 name
"wangwu"
127.0.0.1:6379> hget user:1 age
"50"
127.0.0.1:6379> hget user:1 agea
(nil)

hsetnx命令

hsetnx命令只有当field的field在hash中不存在时才创建该field，并返回创建的filed个数。如果hash中field已经存在则什么都不做，返回0。

127.0.0.1:6379> help hsetnx

  HSETNX key field value
  summary: Set the value of a hash field, only if the field does not exist
  since: 2.0.0
  group: hash

127.0.0.1:6379> hsetnx nxset keynx 1
(integer) 1
127.0.0.1:6379> hget nxset keynx
"1"
127.0.0.1:6379> hsetnx nxset keynx 2
(integer) 0
127.0.0.1:6379> hget nxset keynx
"1"
127.0.0.1:6379> hsetnx nxset keynx2 2
(integer) 1
127.0.0.1:6379> hget nxset keynx2
"2"
127.0.0.1:6379>

hmset命令

hmset命令已经由hset命令替换，语法和hset类似

127.0.0.1:6379> help hmset

  HMSET key field value [field value ...]
  summary: Set multiple hash fields to multiple values
  since: 2.0.0
  group: hash

127.0.0.1:6379> hmset mhash mkey1 mv1 mkey2 mv2
OK
127.0.0.1:6379> hget mhash mkey1
"mv1"
127.0.0.1:6379> hget mhash mkey2
"mv2"
127.0.0.1:6379>

hmget命令

hmget命令用来获取多个fields对应的value，如果某个fields不存在该field对应的value则返回nil。如果该hash对象不存在，则每个fields都返回nil。

127.0.0.1:6379> hset user:1 name wangwu age 50 sex m
(integer) 3
127.0.0.1:6379> hset user:2 name lisi  age 28
(integer) 2
127.0.0.1:6379> hmget user:1 name age sex
1) "wangwu"
2) "50"
3) "m"
127.0.0.1:6379> hmget user:2 name age
1) "lisi"
2) "28"

hlen命令

hlen命令获取hash中 fields的个数。

127.0.0.1:6379> help hlen

  HLEN key
  summary: Get the number of fields in a hash
  since: 2.0.0
  group: hash

127.0.0.1:6379> hset user:1 name wangwu age 50 sex m
(integer) 3
127.0.0.1:6379> hlen user:1
(integer) 3
127.0.0.1:6379> hlen user:2
(integer) 0
127.0.0.1:6379>

hstrlen命令

hstrlen命令获取hash中具体field对应的value字符串的长度。

127.0.0.1:6379> help hstrlen

  HSTRLEN key field
  summary: Get the length of the value of a hash field
  since: 3.2.0
  group: hash

127.0.0.1:6379> hset user:1 name wangwu age 50 sex m
(integer) 3
127.0.0.1:6379> hstrlen user:1 name
(integer) 6
127.0.0.1:6379> hstrlen user:1 age
(integer) 2
127.0.0.1:6379> hstrlen user:1 sex
(integer) 1
127.0.0.1:6379>

hkeys命令

hkeys命令获取hash中所有的fields。当hash不存在时，返回empty array, hash存在则返回所有的fields。

127.0.0.1:6379> help hkeys

  HKEYS key
  summary: Get all the fields in a hash
  since: 2.0.0
  group: hash

127.0.0.1:6379> hkeys not:exits:hash
(empty array)

127.0.0.1:6379> hset user:1 name wangwu age 50 sex m
(integer) 3

127.0.0.1:6379> hkeys user:1
1) "name"
2) "age"
3) "sex"

hvals命令

hvals获取一个hash中所有fields的value,如果hash不存在则返回empty array。

127.0.0.1:6379> help hvals

  HVALS key
  summary: Get all the values in a hash
  since: 2.0.0
  group: hash

127.0.0.1:6379> hvals not:exists:hash
(empty array)

127.0.0.1:6379> hset user:1 name wangwu age 50 sex m
(integer) 3
127.0.0.1:6379> hvals user:1
1) "wangwu"
2) "50"
3) "m"

hgetall命令

hgetall命令获取hashs中所有的fields信息，包含 field和对应value。

127.0.0.1:6379> help hgetall

  HGETALL key
  summary: Get all the fields and values in a hash
  since: 2.0.0
  group: hash

127.0.0.1:6379> hgetall user:1
1) "name"
2) "wangwu"
3) "age"
4) "50"
5) "sex"
6) "m"
127.0.0.1:6379> hgetall not:exist:hash
(empty array)
127.0.0.1:6379>

hdel命令

hdel命令删除hash中的field。如果field不存在或hash不存在则返回0。如果存在则返回删除的fields个数。

127.0.0.1:6379> help hdel

  HDEL key field [field ...]
  summary: Delete one or more hash fields
  since: 2.0.0
  group: hash

127.0.0.1:6379> hset user:1 name wangwu age 50 sex m
(integer) 1
127.0.0.1:6379> hgetall user:1
1) "name"
2) "wangwu"
3) "age"
4) "50"
5) "sex"
6) "m"
127.0.0.1:6379> hdel user:1 name age no:sex
(integer) 2
127.0.0.1:6379> hgetall user:1
1) "sex"
2) "m"

127.0.0.1:6379> hdel not:exist:hash not:exist:field
(integer) 0

hexists命令

hexists命令判断field是否存在hash中，存在则返回1，否则返回0。

127.0.0.1:6379> help hexists

  HEXISTS key field
  summary: Determine if a hash field exists
  since: 2.0.0
  group: hash

127.0.0.1:6379> hkeys user:1
1) "sex"
127.0.0.1:6379> hexists user:1 name
(integer) 0
127.0.0.1:6379> hexists user:1 sex
(integer) 1

hincrby命令

hincrby命令对hash中field对应的数字value进行整数自增或整数自减，自增increment则为正整数,自减increment为负整数。

127.0.0.1:6379> help hincrby

  HINCRBY key field increment
  summary: Increment the integer value of a hash field by the given number
  since: 2.0.0
  group: hash

127.0.0.1:6379> hincrby user:1 age 1
(integer) 25
127.0.0.1:6379> hget user:1 age
"25"
127.0.0.1:6379> hincrby user:1 age -1
(integer) 24
127.0.0.1:6379> hget user:1 age
"24"
127.0.0.1:6379>

hincrbyfloat命令

hincrbyfloat命令对hash中field对应的浮点数或整数进行浮点数自增或自减。自增increment则为正浮点数,自减increment为负浮点数。

127.0.0.1:6379> help hincrbyfloat

  HINCRBYFLOAT key field increment
  summary: Increment the float value of a hash field by the given amount
  since: 2.6.0
  group: hash

127.0.0.1:6379> hset student:1 name wangling major automation GPA 3.5
(integer) 3
127.0.0.1:6379> hget student:1 GPA
"3.5"
127.0.0.1:6379> hincrbyfloat student:1 GPA 0.3
"3.8"
127.0.0.1:6379> hget student:1 GPA
"3.8"
127.0.0.1:6379> hincrbyfloat student:1 GPA 0.2
"4"
127.0.0.1:6379> hget student:1 GPA
"4"

hrandfield命令

hrandfield命令随机返回hash中 count个 field。后面可以选择接收一个参数或者两个参数 count和withvalue。

127.0.0.1:6379> help hrandfield

  HRANDFIELD key [count [WITHVALUES]]
  summary: Get one or multiple random fields from a hash
  since: 6.2.0
  group: hash

127.0.0.1:6379> hrandfield student:1
"major"

127.0.0.1:6379> hrandfield student:1 1 withvalues
1) "name"
2) "wangling"

127.0.0.1:6379> hrandfield student:1 2
1) "name"
2) "major"

127.0.0.1:6379> hrandfield student:1 2 withvalues
1) "GPA"
2) "4"
3) "name"
4) "wangling"

hscan命令

hscan命令迭代 hash中的field和values。

127.0.0.1:6379> help hscan

  HSCAN key cursor [MATCH pattern] [COUNT count]
  summary: Incrementally iterate hash fields and associated values
  since: 2.8.0
  group: hash

127.0.0.1:6379> hscan student:1 0
1) "0"
2) 1) "name"
   2) "wangling"
   3) "major"
   4) "automation"
   5) "GPA"
   6) "4"

127.0.0.1:6379> hscan student:1 0 match major
1) "0"
2) 1) "major"
   2) "automation"

posted @ 2022-08-13 11:58 panzq 阅读(1017) 评论(0) 编辑收藏举报

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Redis hash类型