Returns the values associated with the specified fields in the hash stored at
key.
For every field that does not exist in the hash, a nil value is returned.
Because a non-existing keys are treated as empty hashes, running HMGET against
a non-existing key will return a list of nil values.
*Return value
Array reply: list of values associated with the given fields, in the same order as they are requested.
redis>
HSET myhash field1 "Hello"
(integer) 1redis> HSET myhash field2 "World"
(integer) 1redis> HMGET myhash field1 field2 nofield
1) "Hello" 2) "World" 3) (nil)