HSETNX key field value
Available since: 2.0.0
Time complexity: O(1)
ACL categories:
@write
@hash
@fast
Sets field in the hash stored at key to value, only if field does not
yet exist.
If key does not exist, a new key holding a hash is created.
If field already exists, this operation has no effect.
Return
Integer reply, specifically:
1iffieldis a new field in the hash andvaluewas set.0iffieldalready exists in the hash and no operation was performed.