set
英[set] 美[sɛt]
vt. Set; place, arrange; put in a certain situation; place tableware
vi. Setting off; setting off; condensation
n.Gathering; a set; a set; a TV set
adj. Fixed; located in...; stubborn; arranged The
third person singular: sets plural: sets present participle: setting past tense: set past participle: set
redis MSETNX command syntax
Function:Set one or more key-value pairs at the same time, if and only if all given keys do not exist. MSETNX will refuse to perform all set operations for a given key, even if only one of the given key already exists.
Syntax:MSETNX key value [key value ...]
Description:MSETNX is atomic, so it can be used as a setting Multiple different keys represent unique logic objects of different fields. All fields are either all set or none are set.
Available versions:>= 1.0.1
Time complexity:O(N), N is the number of keys to be set .
Return:When all keys are successfully set, return 1. If all given keys fail to be set (at least one key already exists), then 0 is returned.
redis MSETNX command example
# 对不存在的 key 进行 MSETNX redis> MSETNX rmdbs "MySQL" nosql "MongoDB" key-value-store "redis" (integer) 1 redis> MGET rmdbs nosql key-value-store 1) "MySQL" 2) "MongoDB" 3) "redis" # MSET 的给定 key 当中有已存在的 key redis> MSETNX rmdbs "Sqlite" language "python" # rmdbs 键已经存在，操作失败 (integer) 0 redis> EXISTS language # 因为 MSET 是原子性操作，language 没有被设置 (integer) 0 redis> GET rmdbs # rmdbs 也没有被修改 "MySQL"