Redis notes

Global operation

**keys *** : Show all the keys

keys *
* For wildcard 
keys *b  Show it all b The key at the end 
keys a*  Show it all a Key at the beginning 

dbsize: The number of all keys in the current library

dbsize

select 1 : Switch redis Library operation

select [1,2,3,4,5...]  There are optional values in brackets 

flushdb: Clear current redis All keys in the Library （ As far as possible need not ）

flushdb  Why should the current library be cleared 

flushall: Clear all redis Key of Library （ As far as possible need not ）

flushall

ttl: Key to view the expiration time

ttl [key]  Keys that never expire ttl by -1

type: see key Data type of

type [key] 

expire: Set the expiration time for a key

expire [key] [ttl] key Key value 、ttl For expiration time 

del: Delete one key

del [key] key As the key 

character string String operation

set： Set up string Type of key-value, If it already exists key be set Override the old value

set key value [ex second ]/[px  millisecond ] [nx]/[xx]ex/px :  Validity of cache   The default is exnx: key When there is no , To perform operations   ( Involving distributed locks )xx: key In existence , Will also perform operations , Update old values   Default 

get： Get the value of the string type key , If not, return nil, If the value of the obtained key is not a string, an error is returned

get [key]

incr： Self increasing , It can be used directly ,key Automatically created , You don't have to set establish

incrby: Specifies the self increment of the step

incr [key]  Self increasing    Increase by one each time incrby [key] [step]  Self increasing  step The specified step size can be negative 

decr: Self reduction Similar to self increase

decrby: Specify the step size to self reduce

decr [key]decr [key] [step]

append: hold value Append to key The original value of

append [key] [value] key As the key ,value For the value to be appended . Notice that there is no key You can also successfully create , The value is appended value

getset: Take this key Get the old value of and set the new value

getset [key] [value] key As the key  value For the new value 

list List operation

lpush: from list On the left ( Head ) Insert elements

lpush [key] [value]

rpop : from list To the right of ( The tail ) Delete the element and return the element value

rpop [key]

llen: Get the number of values stored in the list

llen [key]  Get the number of values stored in the list 

ltrim Intercept the values in the list

ltrim [key] [start] [stop]  Intercept the values in the list by index 

lrange： Get the value in the list

lrange [key] [start] [stop] start Index for start  end Index for the end  

The index is shown in the following table

Positive index	0	1	2
Values in the list	2	3	4
De index	-3	-2	-1

We can get all the values as :

lrange [key] 0 -1

rpoplpush: Remove the last element of the list , And add the element to another list , Return the element

( It is often used to complete logging )

rpoplpush [key1] [key2]  here key1 For the source list key key2 For the target list key

Hash hash operation

hset Set up hash Value

hmset Set up multiple hash Value

hset [key] [field] [value]  hold key Medium field The value of the field is set to value, If there is a need key、value Coverage hmset [key] [field1] [value1] [field2] [value2] [field3] [value3]  Set up multiple hash Value 

hget obtain hash It is specified in key The specified field Value

hmget obtain hash Present in China key The multiple field Value

hgetall Get current key All field And value

hget [key] [field]  obtain hash It is specified in key The specified field Value hmget [key] [field1] [field2] [field3]  obtain hash Present in China key The multiple field Value hgetall [key]  obtain key Middle all field And value 

hdel Delete hash Of key Of field

hdel [key] [field]  Delete hash Of key Of field Can write multiple field

hlen obtain hash Number of records in , That is to say key Medium field Count

hlen [key]

hexists Get current hash Medium key Of field Whether there is

hexists [key] [field]

hkeys Get current key All field Value

hkeys [key]  Get current key All field Value 

hvals Get current key All value Value

hkeys [key]  Get current key All value Value 

hincrby Will specify key The specified field The value of increases by the specified amount

hincrby [key] [field] [step]  Will specify key The specified field The value of self incrementing specified step Number 

aggregate (set) operation

redis Of set Is an unordered set . In the assembly Duplicate elements are not allowed

set The element can contain at most (2 Of 32 Power -1) Elements .

scene ： Store users ID, Non repeating information 、 Luck draw 、 Friend relationship

sadd: towards set Set assignment key Insert elements in

sadd [key] [value1] [value2] [value3] ...  towards set Set assignment key Insert elements in 

smembers: Returns the specified key Set set All the elements in

smembers [key]

scard Returns the total number of elements in the specified set

scard [key]

srem Delete the specified element of the specified set

srem [key] [value]

spop Randomly delete the elements of the specified set

spop [key] [count]  here count The parameter is to pop up a specified number of elements randomly , When count If it is greater than the total number of sets, it means all pops up 

sismember: View the specified key Does the element of exist

sismember [key] [value]  here key As the key value Specify the element for 

smove Put value Delete , And added to the target set

smove [set1] [set2] [value]   here set1 For source collection ,set2 Specify the set for ,value For elements that need to be moved 

sinter： Find out key1,key2 The intersection of two sets

sinter key1 key2

sunion: Find out key1,key2 The union of two sets

sunion key1 key2

sdiff： Find out key1 key2 Difference set between , Different order , The results are different

sdiff key1 key2

The following picture is the relationship between them , Where union is all a and b The element of removes duplicate values .

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Ordered set (set) operation

Elements are not allowed to repeat , Each element is associated with a score , You can sort by its score . Such as mobile phones APP Realization of market software ranking and other requirements .

zadd Assign key Additive elements

zadd [key] [score] [value]  here score Is the score  

zrem Delete ordered set assignment key The elements of

zrem [key] [value] 

zrange Query the ordered set to specify key The elements of ( From small to large )

zrange [key] [start] [end] [withscorces]  here strat end and lrange Agreement ,withscorces It can be omitted, and if there is, the score will be displayed , If there is no default, the score will not be displayed .zrange Sort from small to large 

**zrevrange ** Query the ordered set to specify key The elements of ( From big to small )

zrevrange [key] [start] [end] [withscorces]  The parameters are consistent with the above , Here is the order from big to small 

zcard Get the ordered set assignment key Number of elements of

zcard [key]

zscore Get the ordered set assignment key The score of the specified element of

zscore [key] [score]

zcount Get the ordered set assignment key The number of elements between the fractions of

zcount [key] [min] [max]   The statistics here are min<=score<=max Number 

zremrangebyscore Delete value

zremrangebyscore [key] [min] [max]