What is the difference between HSET and HMSET method in redis database
HSET used to be able to set only one key-value pair. And if you needed to set several at once, you would have to use HMSET (M for multi). That was changed a few years ago, to allow both commands to accept multiple pairs. And now HMSET is redundant.
From official documentation:
As per Redis 4.0.0, HMSET is considered deprecated. Please use HSET in new code.
Sets field in the hash stored at key to value. If key does not exist, a new key holding a hash is created. If field already exists in the hash, it is overwritten.
HMSET key field value [field value ...]
Sets the specified fields to their respective values in the hash stored at key. This command overwrites any existing fields in the hash. If key does not exist, a new key holding a hash is created.
For more redis commands information, click here.
The only difference between the commands HSET and HMSET is the return value of the commands.
HSET return value (Integer reply):
#if the field is a new field in the hash and value was set. (where#is the number of new fields created )- 0 if the field already exists in the hash and the value was updated.
HMSET returns a simple string as a reply.