How to make five kinds of data structures in redis

redis data structure

redis yes key-value Data structure of , Every piece of data is ⼀ Key value pairs , The type of key is string , Bonds cannot be repeated .

There are five types of values ：

1. character string string： The string type is Redis The most basic data storage type in , One key Corresponding to one value.
   string Type in the Redis Is binary safe . This means that the type can accept data in any format , such as JPEG Image data or JSON Object description information, etc . stay Redis Of string type Value The maximum length of data that can be held is 512M.

2. Hash hash： It's a key value (key=>value) The collection . Ideal for storing objects .

3. list list： A simple list of strings , Sort by insertion order . You can add an element to the head of the list ( On the left ) Or tail ( On the right ).

4. aggregate set：string Unordered collection of type . Through the hash table , add to , Delete , The complexity of searching is O (1).

5. Ordered set zset： and set The same is true. string Collection of type elements , And duplicate members are not allowed . The difference is that each element is associated with a double Score of type .redis It's the scores that sort the members of a collection from small to large .zset Members of are unique , But fractions (score) But it can be repeated .

string Storage

#  set key value : set key value
127.0.0.1:6379> set name xiaoming

#  Set key expiration time , The unit is in seconds : setex key1 seconds  value
127.0.0.1:6379> setex name 3 xiaoming
    
#  Set multiple key values  mset key1 value1  key2 value2
127.0.0.1:6379> mset name xiaoming age 18

#  Additional value  append key value
127.0.0.1:6379> append name ge
(integer) 10
127.0.0.1:6379> get name
"xiaomingge"

#  obtain ：  Get value from key , There is no return  null get key
127.0.0.1:6379> get name

#  obtain :  Return multiple values according to multiple keys  mget key1 key2
127.0.0.1:6379> mget name age
1) "xiaomingge"
2) "18"

#  Look at all the keys 
127.0.0.1:6379> keys *
1) "name"
2) "age"

#  Lookup key , regular expression : keys pattern
127.0.0.1:6379> keys n*
1) "name"


#  Judge whether the key exists , If there is a return  1, There is no return  0：exists key
127.0.0.1:6379> exists name
(integer) 1
127.0.0.1:6379> exists aa
(integer) 0

#  View the type corresponding to the key 
127.0.0.1:6379> type name
string

#  Delete key and corresponding value  del key1 key2
127.0.0.1:6379> del name age
(integer) 2

#  Set expiration time for existing keys  -1:  Represents never expires  -2： Represents expired deletion 
127.0.0.1:6379> set name a
OK
127.0.0.1:6379> expire name 20
(integer) 1
127.0.0.1:6379> ttl name
(integer) 17    #  Expiration time remains 17 second  
127.0.0.1:6379> ttl name
(integer) -2    #  Indicates that the key value has expired and been deleted 

hash Storage

#  Set individual properties : hset key field value
127.0.0.1:6379> hset user name xiaoming
(integer) 1

#  Set multiple properties : hmset key field1 value1 field2 value2
127.0.0.1:6379> hset user name xiaoming age 18
(integer) 1

#  Gets all the properties of the specified key : hkeys key
127.0.0.1:6379> hkeys user
1) "name"
2) "age"

#  Get the value of a property : hget key field
127.0.0.1:6379> hget user name
"xiaoming"

#  Get values for multiple properties : hmget key field1 field2
127.0.0.1:6379> hmget user name age
1) "xiaoming"
2) "18"

#  Get the values of all properties : hvals key
127.0.0.1:6379> hvals user
1) "xiaoming"
2) "18"

#  Delete the whole hash  Key and its value , Use  del

#  Delete attribute , The values corresponding to the attributes are deleted together : hdel key diled1 dile2
127.0.0.1:6379> hdel user name age
(integer) 2

list Storage

#  Insert data on the left : lpush key value1 value2 ( In reverse order )
127.0.0.1:6379> lpush name a b
(integer) 2

#  Insert data on the right : rpush key value1 value2 ( positive sequence )
127.0.0.1:6379> rpush name c d 
(integer) 4

#  Insert a new element before and after the specified element : linsert key before or after  Existing elements   The new element 
127.0.0.1:6379> linsert name before a  xiaoming   #  stay  a  Add a new element before the element  xiaoming
(integer) 5

#  obtain  -  Returns the elements within the specified range in the list : lrange key start stop,  The first element is  0,-1  Represents the last element 
##  obtain name  List all elements 
127.0.0.1:6379> lrange name 0 -1
1) "b"
2) "xiaoming"
3) "a"
4) "c"
5) "d"

#  Set the element value of the specified position : lset key index value
##  The index starts on the left , The first ⼀ Elements are  0. The index can be negative , Indicates that the tail starts counting , Such as  - 1  Said the last ⼀ Elements 
127.0.0.1:6379> lset name 4 a   #  This setting is equivalent to indexing wei 4  The elements of   It is amended as follows  a
OK
127.0.0.1:6379> lrange name 0 -1
1) "b"
2) "xiaoming"
3) "a"
4) "c"
5) "a"    #  It used to be  d   Be modified 

#  Delete  -  Deletes the specified element ：lrem key count value
##  Put the list before count The value of the second occurrence is value Remove the elements of ,count > 0:  Remove from the beginning to the end ,count < 0:  Remove from the tail to the head ,count = 0:  Remove all 
127.0.0.1:6379> lrem name 0 b  #  Remove elements  b
(integer) 1

set Storage

#  Additive elements ：sadd key member1 member2 ...
127.0.0.1:6379> sadd name 1 2
(integer) 2

#  Get all the elements : smembers key
127.0.0.1:6379> smembers name
1) "1"
2) "2"

#  Deletes the specified element : srem key
127.0.0.1:6379> srem name 1
(integer) 1
127.0.0.1:6379> smembers name
1) "2"

zset Storage

#  add to : zadd key score1 member1 score2 member2
127.0.0.1:6379> zadd name 2 xiaom 1 xiaoh
(integer) 2

#  obtain  -  Returns the elements in the specified range : zrange key start stop
127.0.0.1:6379> zrange name 0 -1
1) "xiaoh"
2) "xiaom"

##  return score Values in min  and max  Member between : zrangebyscore key min max
127.0.0.1:6379> zrangebyscore name 1 2
1) "xiaoh"
2) "xiaom"

##  Return members memberd score value : zscore key member
127.0.0.1:6379> zscore name xiaom
"2"

#  Delete  -  Deletes the specified element : zrem key member1 member2 ...
127.0.0.1:6379> zrem name xiaom
(integer) 1

##  Delete the element whose weight is within the specified range : zremrangebyscore key min max
127.0.0.1:6379> zremrangebyscore name 0 2
(integer) 1