How to store array of hashes in redis

I want to store array of hashes in redis , what is best way to code it ?

2 Answers

The only way AFAIK is to de-reference them. Say you have an array of 2 hashes like: {foo: 'bar', baz: 'qux'}.

You'd store them separately, and then create a SET that references them all:

HMSET myarr:0 foo bar baz qux SADD myarr myarr:0 HMSET myarr:1 foo bar baz qux SADD myarr myarr:1 

Then you can retrieve them all by querying the set: SMEMBERS myarr and then call HGETALL <key> on all the returned keys to rebuild your original array of hashes.

I hope this makes sense. And if you find a smarter way I'd be happy to hear it.

If you are using a language which supports to/from json conversion, you can convert your hash to json and append it in a list. You can do the following in Ruby:

require 'rubygems' require 'redis' require 'json' require 'pp' redis = Redis.new(:host => '127.0.0.1', :port => 6379) h1 = { :k1 => 'v1', :k2 => 'v2' } redis.rpush('arr', h1.to_json) h2 = { :k3 => 'v3', :k4 => 'v4' } redis.rpush('arr', h2.to_json) hashes = redis.lrange('arr', 0, -1) hashes.map! { |x| JSON.parse(x) } pp hashes