HSETNX

Usage:

HSETNX key field value

Complexity:

O(1)

Since:

2.0.0

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.

Examples

HSETNX myhash field "Hello"
HSETNX myhash field "World"
HGET myhash field