Sets the specified fields to their respective values in the hash stored at
key.
This command overwrites any specified fields already existing in the hash.
If key does not exist, a new key holding a hash is created.
Alternative
HSET with multiple field-value pairs.
Examples
127.0.0.1:6379> HMSET myhash field1 "Hello" field2 "World"
OK
127.0.0.1:6379> HGET myhash field1
"Hello"
127.0.0.1:6379> HGET myhash field2
"World"