HSETNX key field value

Available since 2.0.0.

Time complexity: O(1)

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 value

Integer reply, specifically:

  • 1 if field is a new field in the hash and value was set.
  • 0 if field already exists in the hash and no operation was performed.

*Examples

redis>  HSETNX myhash field "Hello" 
(integer) 1
redis>  HSETNX myhash field "World" 
(integer) 0
redis>  HGET myhash field 
"Hello"
redis>