HSETNX

Syntax

1. HSETNX key field value

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

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

1. dragonfly> HSETNX myhash field "Hello"
2. (integer) 1
3. dragonfly> HSETNX myhash field "World"
4. (integer) 0
5. dragonfly> HGET myhash field
6. "Hello"