Get redis hash data via cli

Question

I've been experimenting with Redis today. I've managed to store cached values from Drupal, but I'm looking to investigate a bit further and view the value stored in cache_my_custom_cache..

127.0.0.1:6379> keys *
 1) "ff3169bd93659dc31322abc32835ef3e:cache_bootstrap:lookup_cache"
 2) "ff3169bd93659dc31322abc32835ef3e:cache_bootstrap:module_implements"
 3) "ff3169bd93659dc31322abc32835ef3e:cache_bootstrap:bootstrap_modules"
 4) "ff3169bd93659dc31322abc32835ef3e:cache_bootstrap:system_list"
 5) "ff3169bd93659dc31322abc32835ef3e:cache_bootstrap:variables"
 6) "ff3169bd93659dc31322abc32835ef3e:path:a:und"
 7) "myhash"
 8) "ff3169bd93659dc31322abc32835ef3e:path:s:und"
 9) "ff3169bd93659dc31322abc32835ef3e:cache_my_custom_cache:custom_cache_markup"
10) "ff3169bd93659dc31322abc32835ef3e:cache_bootstrap:hook_info"

127.0.0.1:6379> type ff3169bd93659dc31322abc32835ef3e:cache_my_custom_cache:custom_cache_markup
hash

• this reveals it's of type hash.. But when I run:

127.0.0.1:6379> HGET ff3169bd93659dc31322abc32835ef3e:cache_qbe:qbe_markup
(error) ERR wrong number of arguments for 'hget' command

It doesn't like it! Completely new to this, can someone offer a solution?

Answer 1

Besides the key you will need to specify the field in the HGET command.

To get a list of all fields in the hash you can run this:

hkeys ff3169bd93659dc31322abc32835ef3e:cache_my_custom_cache:custom_cache_markup

Then you can do:

hget ff3169bd93659dc31322abc32835ef3e:cache_my_custom_cache:custom_cache_markup FIELD

You can also get all the values in the hash like this:

hvals ff3169bd93659dc31322abc32835ef3e:cache_my_custom_cache:custom_cache_markup

Answer 2

HGET expects an additional parameter after the key name that enumerates which field of your hash you would like returned. Something like this:

HGET my_hash_key my_hash_field

If you're trying to retrieve all fields of your hash at once, you should use HGETALL:

HGETALL my_hash_key

Documentation for HGET: here

Documentation for HGETALL: here

Discussion of Redis types (including hashes): here