Sets the value of a field in a hash only when the field doesn’t exist.
HSETNX
key field value
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.
One of the following:
Integer reply: 0
if the field already exists in the hash and no operation was performed.
Integer reply: 1
if the field is a new field in the hash and the value was set.
O(1)
@fast @hash @write
127.0.0.1:6379> HSETNX myhash field "Hello"
(integer) 1
127.0.0.1:6379> HSETNX myhash field "World"
(integer) 0
127.0.0.1:6379> HGET myhash field
"Hello"
HDEL, HEXISTS, HGET, HGETALL, HINCRBY, HINCRBYFLOAT, HKEYS, HLEN, HMGET, HRANDFIELD, HSCAN, HSET, HSTRLEN, HVALS.