decr

UK['d?kr] US['d?kr]

abbr.decrease reduce; become less; decrement(al)(ly) reduce; reduce Value

by

UK[ba?] US[ba?]

prep.beside...;expression;because;after

adv. pass; means to reserve or save; use; to visit briefly

redis DECRBY command syntax

Function: Subtract the decrement from the value stored in key.

Syntax: DECRBY key decrement

Description: If key does not exist, then the value of key will be initialized to 0 first, and then executed DECRBY operation. If the value contains the wrong type, or a value of type string cannot be represented as a number, an error is returned. The value of this operation is limited to 64-bit signed number representation.

Available versions: >= 1.0.0

Time complexity: O(1)

Return: The value of key after subtracting decrement.

redis DECRBY command example

# 對(duì)已存在的 key 進(jìn)行 DECRBY
redis> SET count 100
OK
redis> DECRBY count 20
(integer) 80
# 對(duì)不存在的 key 進(jìn)行DECRBY
redis> EXISTS pages
(integer) 0
redis> DECRBY pages 10
(integer) -10