HVALS command in Redis is often used when you need to retrieve all the values associated with a specific hash key. This can be particularly useful in situations where you have stored data in a hash structure, and you want to quickly extract all the values without knowing their specific field names.
You need the Predis library to work with Redis in PHP. You can install it via composer:
composer require predis/predis.
Here's an example of how you might use the
HVALS command in PHP using the Predis client:
In this script, we first add three fields to a hash named
'hash'. We then use the
hvals function to retrieve all the values from the hash. The result would be an array containing the values
['value1', 'value2', 'value3'].
HVALSprovides a quick way to get all values in a hash, be aware that it doesn't return any associated keys. If you need both keys and values, consider using the
HVALSon large hashes. As it returns all values in the hash, it could consume significant memory or network bandwidth.
HVALSreturns all the values of a hash, whereas
HKEYSreturns all the keys.
HVALScould be attempting to use it on non-hash types. Remember that
HVALScan only be used with hashes.
Q: Can I use
HVALS on a key that is not a hash?
HVALS only works on hash keys. If you try to use it on a key associated with another data type, Redis will return an error.
HVALS maintain the order of the values?
HVALS retrieves values in the order they were added to the hash.