Redis Hsetnx command
Redis Hsetnx command is used to hash table does not exist in the field of assignment.
If the hash table does not exist, a new hash table is created and HSET operation.
If the field already exists in the hash table, the operation is invalid.
If the key does not exist, a new hash table is created and executed HSETNX command.
grammar
redis Hsetnx basic command syntax is as follows:
redis 127.0.0.1:6379> HSETNX KEY_NAME FIELD VALUE
Available versions
> = 2.0.0
return value
Set successfully, returns 1. If the given field already exists and no operation is performed, 0 is returned.
Examples
redis 127.0.0.1:6379> HSETNX myhash field1 "foo" (integer) 1 redis 127.0.0.1:6379> HSETNX myhash field1 "bar" (integer) 0 redis 127.0.0.1:6379> HGET myhash field1 "foo" redis 127.0.0.1:6379> HSETNX nosql key-value-store redis (integer) 1 redis 127.0.0.1:6379> HSETNX nosql key-value-store redis # 操作无效， key-value-store 已存在 (integer) 0