Redis data types and commands

Redis data types and commands

Basic data type

String-String

I saved two data in advance k:v,z:c
10

Append string

Append a string, if it does not currently exist, it is equivalent to set

APPEND xxx value

Get string length

STRLEN XXX
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Automatically add 1

INCR XXX

Automatically subtract 1

DECR XXX

Set the step size, specify the increment

INCRBY XXX 数值

Set the step size, specify the decrement

DECRBY XXX 数值 
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Intercept string

GETRANGE k 0 3   #截取字符串[0,3] 

GETRANGE k 0 -1  #获得全部的字符串

Replace the string starting at the specified position

SETRANGE k 1 xx
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Set expiration time

setex (set with expire)
setex k 10 hello   #存入数据 k:"hello" 有效时间 10s
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No more settings

setnx (set if not exist)
setnx k 11     #如果 k 不存在,存入数据 k:"11"
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Set multiple values ​​at the same time

mset k1 v1 k2 v2 k3 v3

Get multiple values ​​at the same time

mget k1 k2 k3

Multiple values ​​do not exist and then set

msetnx k1 v1 k4 v4   # 该操作是一个原子性操作,一个失败 全部失败
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Access object

user: {id}: {filed}
mset user:1:name zc user:1:age 20   

mget user:1:name user:1:age
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Get first and then deposit

getset k v
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List-List

In redis inside, we can listbecome, stacks, queues, blocking queue

Save data (head insertion)

LPUSH list one             # 存入list列表,数据为 one
  
LPUSH list two three       # 存入list列表,数据为 two、three

Save data (end insert)

RPUSH list right           # 存入list列表,数据为 right

Get data in a specified range

LRANGE list 0 1            # 获取list列表 0 1 数据
                          
LRANGE list 0 -1           # 获取list列表全部数据
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Fetch data (from the head)

LPOP xxx

Take out the data (from the tail)

RPOP xxx

Obtain value by subscript

lindex xxx index

Get list length

llen xxx          
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Remove specified value

lrem list 2 two         # 移除list列表中 2 个 two , 移除数量多于现存数量的话,会全部移除 不报错
twenty one

Intercept data of specified length

Through the subscript, intercept the specified length data, it will directly change the original list
ltrim list 1 2         # 截取list列表,1-2 元素
twenty two

Remove elements from the list and move to a new list

rpoplpush list list1   # 移除list列表的最后一个元素,将他移动到list1列表中 
twenty three

Replace the value at the specified position

For this statement, to meet:
  • The list exists
  • There is data at the specified position in the list
lset list 0 test    #将list列表第0个位置的数据替换为test
twenty four

Insert specific value

LINSERT list before v3 v2   # 在list列表中的v3数据 前 插入v2

LINSERT list after v3 v4    # 在list列表中的v3数据 后 插入v4
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Set-Set

The set cannot be read repeatedly

Save and get data

sadd set hello           #存入一个数据,存入hello到set集合中

sadd set v1 v2 v3        #存入多个数据,存入v1、v2、v3到set集合中

smembers set             #查看set集合中所有数据
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Determine whether the value is in the set

sismember set hello    #判断hello是否在set集合中
 
sismember set v1       #判断v1是否在set集合中
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Get the number of set collection data

scard set     
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Remove the specified element of the set collection

srem set hello        #set集合中移除hello
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Randomly get elements

srandmember set        #随机获取set集合1个元素

srandmember set 2      #随机获取set集合2个元素
twenty one

Randomly delete elements

spop set              #随机删除1个元素

spop set 2            #随机删除2个元素
twenty two

Move the specified value to another collection

smove set set1 v2    #将v2元素从set集合移动到set1集合
twenty three

Digital collection class

  • Subtraction
  • Intersection
  • Union
sdiff set1 set2     #set1集合和set2集合的差集(set1存在,set2不存在)
sinter set1 set2    #set1、set2集合中的交集,即两者都存在的元素
sunion set1 set2    #set1、set2并集
twenty four

Hash-Hash

Map collection, key-may, this value is a map collection, the essence is not much different from the string type, it is still a key-value
Hash is more suitable for storing objects, string is more suitable for string storage

Store an element

hset hash k v       #存入hash集合,k-v

Get an element

hget hash k         #获取hash集合 k元素对应v

Store multiple elements

hmset hash k1 v1 k2 v2   #存入hash集合 k1-v1 k2-v2

Get multiple elements

hmget hash k1 k2     #获取hash集合 k1、k2元素对应v

Get all the data

hgetall hash

Get the number of fields in the collection

hlen hash

Delete the corresponding element

hdel hash k          #删除hash集合,k字段
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Get all k fields

hkeys hash

Get all value

hvals hash

Determine whether the specified field exists

hexists hash k1      #判断hash集合中k1字段是否存在
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Increase specified increment

hincrby hash k 2       #hash集合k字段的v+2

hincrby hash k -1      #hash集合k字段的v-1
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No more settings

hsetnx hash k4 v4     #hash集合中 k4字段不存在的话,存入k4-v4
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Zset-ordered set

In the set collection, set k1 v1; it is an unordered non-repeating collection
In the zset collection, zset k1 score1 v1; it is an ordered non-repeated collection

Add the value in the collection

zadd zset 1 one          #添加zset集合元素one,顺序为1

zadd zset 2 two 3 three  #添加zset集合元素two、three,顺序为2、3

Get the set value in the range

zrange zset 0 -1         #获取全部集合值

zrange zset 0 1          #获取集合中0-1的值
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Get the number in the set

zcard zset

From small to large, display all data

zrangebyscore zset -inf +inf    #从小到大,显示全部数据

zrangebyscore zset -inf 2       #从小到大,显示最小到2的数据

zrangebyscore zset -inf 2 withscores #从小到大,显示最小到2的数据并且带着排序数字

From big to small, display all data

zrevrange zset 0 -1
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Get the number of elements in a specified interval

zcount zset 0 2         #获取0-2的元素数量

zcount zset 0 10        #获取0-10的元素数量,超过现存最大值,会显示全部数量,不会报错

Remove the specified element in the collection

zrem zset two           #移除zset集合中two元素
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Special data types

Geospatial-geographic location

Six commands:
  • GEOADD: Add geographic location
  • GEOPOS: Get the accuracy and latitude of the specified city
  • GEODIST: View the straight-line distance between the two
  • GOERADIUS: Take the given latitude and longitude as the center, find the elements within a certain radius
  • GEORADIUSBYMEMBER: Find out other elements located around the specified element
  • GEOHASH: Returns the Geohash representation of one or more location elements
Longitude and latitude query of Chinese cities: http://www.jsons.cn/lngcode/

Add location

The two poles cannot be added directly, generally the city data will be downloaded and imported at one time through the program
The valid longitude is between -180 degrees and 180 degrees; the valid latitude is between -85.05112878 degrees and 85.05112878 degrees.
geoadd china:city 116.405285 39.904989 beijing              #加入中国城市地理位置,经、纬度,beijing

geoadd china:city 113.665412 34.757975 zhengzhou 125.14904 42.927 xian  #加入两条记录

Get the accuracy and latitude of the specified city

geopos china:city beijing
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See the straight-line distance between the two

unit:
  • [ Default ] m: means the unit is meter
  • km: the unit is kilometers
  • mi: expressed in miles
  • ft: expressed in feet
geodist china:city beijing shanghai          #查看 北京到上海 的直线距离,默认单位为米

geodist china:city zhengzhou xian km         #查看 郑州到西安 的直线距离,单位为千米
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Take the given latitude and longitude as the center, find the elements within a certain radius

georadius china:city 110 30 1500 km                   # 以110,30这个经纬度为中心,寻找1500km内的城市

georadius china:city 110 30 1500 km withdist          # 以110,30这个经纬度为中心,寻找1500km内的城市,并显示到中间距离的位置

georadius china:city 110 30 1500 km withdist count 2  # 以110,30这个经纬度为中心,寻找1500km内的城市,只显示两条,并显示到中间距离的位置

georadius china:city 110 30 1500 km withcoord         # 以110,30这个经纬度为中心,寻找1500km内的城市,并显示查出城市的定位信息

georadius china:city 110 30 1500 km withcoord count 2 # 以110,30这个经纬度为中心,寻找1500km内的城市,只显示两条,并显示查出城市的定位信息
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View other elements around the specified element

georadiusbymember china:city beijing 1000 km     # 查看北京元素1000km以内的其他元素

georadiusbymember china:city shanghai 500 km     # 查看上海元素500km以内的其他元素
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Return the Geohash representation of the position element

Convert the two-dimensional latitude and longitude into a one-dimensional string, if the two strings are closer, then the distance is closer
geohash china:city beijing shanghai xian
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The underlying realization principle

The underlying implementation principle of GEO is actually Zset, we can use the Zset command to operate GEO
127.0.0.1:6379> zrange china:city 0 -1      # 查看china:city集合中全部元素
1) "hangzhou"
2) "shanghai"
3) "zhengzhou"
4) "beijing"
5) "xian"
127.0.0.1:6379> zrem china:city xian        # 移除china:city集合中xian元素
(integer) 1
127.0.0.1:6379> zrem china:city shanghai    # 查看china:city集合中shanghai元素
(integer) 1
127.0.0.1:6379> zrange china:city 0 -1      # 查看china:city集合中全部元素
1) "hangzhou"
2) "zhengzhou"
3) "beijing"

Hyperloglog-Cardinality Statistics

Base numbers can be compared
A = {1, 2, 3} = 3; B = {1, 2, 3, 4, 4} = 4
Cardinality {unique elements} = xxx
Advantages: memory occupied fixed, 2 ^ 64 (long) elements of different techniques, only 12KB of memory, from memory if the angle Hyperloglog preferred
0.81% error rate is negligible.

Create a set of elements

127.0.0.1:6379> pfadd hype a b c d

Base number of statistical elements

pfcount hype 

Combine two sets of elements

pfmerge hype2 hype hype1           #将hype、hype1 合并成 hype2
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Bitmaps-bitmap scene

Bit storage

Bitmaps bitmap, is the operation of binary bits to record, there are only two states of 0 and 1.

365 days = 365bit; 1 byte = 8bit; about 46 bytes

Simulate weekly check-in
setbit name date (0-6) Whether to check in (0 not check in, 1 check in)
127.0.0.1:6379> setbit sign 0 1   #周一 已打卡
(integer) 0
127.0.0.1:6379> setbit sign 1 1   #周二 已打卡
(integer) 0
127.0.0.1:6379> setbit sign 2 0   #周三 未打卡
(integer) 0
127.0.0.1:6379> setbit sign 3 0   #周四 未打卡
(integer) 0
127.0.0.1:6379> setbit sign 4 1   #周五 已打卡
(integer) 0
127.0.0.1:6379> setbit sign 5 1   #周六 已打卡
(integer) 0
127.0.0.1:6379> setbit sign 6 1   #周日 已打卡
(integer) 0
127.0.0.1:6379> getbit sign 0     #查询周一是否打卡
(integer) 1
127.0.0.1:6379> getbit sign 3     #查询周四是否打卡
(integer) 0
127.0.0.1:6379> bitcount sign     #查询这周一共打卡几天
(integer) 5
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