Redis: hash type data operation command

single key： object （ Property name - Property value ...）

Hash type (hash)

Redis Of hash It's a string Type of key and value Mapping table , there value It's a series of key-value pairs ,hash Ideal for storing objects .

The general idea of hash type data operation is through key and field operation value,key It's a data ID ,field Is domain ,value It's our feeling

Business data of interest .

 

 

1.hset

grammar ：hset  key  field  value  [field  value …]

function ： Set the key value to field-value Set to Hash list key in , If key non-existent , Then create a new Hash list , The assignment is then performed , If key Under the field Already exist , be value Value override .

Return value ： Returns the number of key value pairs successfully set .

  for example ：

2.hget

grammar ：hget key field

function ： Get hash table key Given domain in field Value .

  Return value ：field Domain value , If key Nonexistence or field There is no return nil.

  for example ：

 

3.hmset and hset Function as

grammar ：hmset key  field value [field value…]

function ： There will be more than one field-value ( Domain - value ) Set to hash table key in , This command will overwrite the existing field,hash surface key non-existent , Create empty hash surface , Re execution hmset.

Return value ： Set successfully returned ok, If it fails, an error is returned .

  for example ：

 

 

4.hmget

grammar ：hmget key field [field…]

function ： Get hash table key The value of one or more given fields in

Return value ： Return and field The value corresponding to the order , If field non-existent , return nil.

for example ：

 

Don't know hsah Medium file Time use ：

5.hgetall

grammar ：hgetall key

function ： Get hash table key All fields and values in

Return value ： Return... As a list hash The values of the middle field and the field ,key non-existent , Returns an empty hash.

 

for example ：

 

 

6.hdel

grammar ：hdel key field [field…]

function ： Delete hash table key One or more specified domains in field, non-existent field Direct to ignore .

Return value ： Successfully deleted field The number of .

for example ：

 

 

7.hlen

grammar ：hlen key

function ： Get hash table key Mesosphere field The number of

Return value ： The number ,field The number of .key There is no return 0.

for example ：

 

8.hexists

grammar ：hexists key field

function ： Look at the hash table key in , Given domain field Whether there is

Return value ： If field There is , return 1, Other return 0. 

  for example ：stu1002 above name Has deleted

 

9.hkeys

grammar ：hkeys key

function ： Look at the hash table key All in field Domain list

Return value ： Contains all the field A list of ,key There is no return empty list

for example ：

 

10.hvals

grammar ：hvals key

function ： Return hash table   List of values for all fields in

Return value ： A list of all the field values in the hash table ,key There is no return empty list .

 

for example ：

 

 

11.hincrby

grammar ：hincrby key field int

function ： To the hash table key Medium field Domain addition int

Return value ： Returns the added field Domain value

for example ：

 

 

 

12.hincrbyfloat

grammar ：hincrbyfloat key field float

function ： To the hash table key Medium field Domain addition float

Return value ： Returns the added field Domain value

 

for example ：

 

13.hsetnx

grammar ：hsetnx key field value

function ： Hash table key In the domain field Is set to value , If and only if domain field Set when it doesn't exist , Otherwise, do not set .

Return value ： Set value returned successfully 1, Other return 0.

 

for example ：