HSTRLEN command in Redis is used when you want to get the length of the value of a hash field. This is commonly used for validating data lengths in Redis hashes before processing that data or displaying it to an end user.
In PHP, using the predis library, this can be accomplished as follows:
This code connects to the Redis server and prints the length of the value stored at the field 'name' in the hash 'user:1'.
This example demonstrates how you might want to check the length of multiple fields within the same hash key.
HSTRLENreturns 0 for non-existing keys or fields.
HSTRLENon a key that is not a hash will result in an error. Always ensure the key points to a hash before using this command.
HSTRLENreturns null for non-existing keys or fields. In reality, it will return 0.
Q: What if I call HSTRLEN on a non-existing key or a non-existing field within an existing hash?
HSTRLEN command will return 0 in both cases.