MSETNX
Syntax
MSETNX key value [key value ...]
Time complexity: O(N) where N is the number of keys to set.
Sets the given keys to their respective values.
MSETNX
will not perform any operation at all even if just a single key already
exists.
Because of this semantic MSETNX
can be used in order to set different keys
representing different fields of a unique logic object in a way that ensures
that either all the fields or none at all are set.
MSETNX
is atomic, so all given keys are set at once.
It is not possible for clients to see that some of the keys were updated while
others are unchanged.
Return
Integer reply, specifically:
1
if the all the keys were set.0
if no key was set (at least one key already existed).
Examples
dragonfly> MSETNX key1 "Hello" key2 "there"
(integer) 1
dragonfly> MSETNX key2 "new" key3 "world"
(integer) 0
dragonfly> MGET key1 key2 key3
1) "Hello"
2) "there"
3) (nil)