redis HINCRBYFLOAT command

incr

abbr.increase (value, price, inventory, amount, production, etc.) increase;increasing increase;increased increase;incremental increase

by

英[baɪ] 美[baɪ]

prep.beside...;expression method;due to;passing through

adv.passing;expressing reservation Or use when saving; short visit

float

英[fləʊt] 美[floʊt]

vt.& vi. (make) float; (make) float; float freely

vi. wander

vt. put forward, draw for consideration; (stock) go public

n. float; floating object; floating board; A drink with ice cream floating on it

Third person singular: floats Plural: floats Present participle: floating Past tense: floated Past participle: floated

redis HINCRBYFLOAT command syntax

Function: Add floating point increment to the field field in the hash table key.

Syntax: HINCRBYFLOAT key field increment

Description: If there is no field field in the hash table, then HINCRBYFLOAT will first add the value of the field field Set to 0 before performing the addition operation. If the key key does not exist, then HINCRBYFLOAT will first create a hash table, then create the field field, and finally perform the addition operation.

Available versions: >= 2.6.0

Time complexity: O(1)

Return: The value of the field field after performing the addition operation.

redis HINCRBYFLOAT command example

# 值和增量都是普通小数
redis> HSET mykey field 10.50
(integer) 1
redis> HINCRBYFLOAT mykey field 0.1
"10.6"
# 值和增量都是指数符号
redis> HSET mykey field 5.0e3
(integer) 0
redis> HINCRBYFLOAT mykey field 2.0e2
"5200"
# 对不存在的键执行 HINCRBYFLOAT
redis> EXISTS price
(integer) 0
redis> HINCRBYFLOAT price milk 3.5
"3.5"
redis> HGETALL price
1) "milk"
2) "3.5"
# 对不存在的域进行 HINCRBYFLOAT
redis> HGETALL price
1) "milk"
2) "3.5"
redis> HINCRBYFLOAT price coffee 4.5   # 新增 coffee 域
"4.5"
redis> HGETALL price
1) "milk"
2) "3.5"
3) "coffee"
4) "4.5"