Node-redis: store json data in redis

[abhinav76]

I am very new to redis. So what i want is store the data retrieved from database. Now do i have to use client.set() for every key-value pair returned by database or is there any other way i can save all the data with one command? Data is of the form:

{
"member_username": "nikhil567",
"member_gender": "Male",
"member_dob": 0,
"member_country": "",
}


[stockholmux]

You probably want to use a hash in Redis. With a hash you can use client.hmset (more info) to store your object.

One note, JS Objects can be nested, but Redis Hashes are only a single level. So, if your data looks something like this:

{ member_name : 'johndoe', address : { street: '123 Any Street', city: 'Anytown' } }

You'll need to use flat before storing it in redis. I wrote an article about that process.

[abhinav76]

@stockholmux my data is stored in variable member. so how would i go about it?
var member={member_name:'svf',address:'cvbjnk'}
can you please give me the example query?

[kulicuu]

The proper way is hashed as explained above, and flat, as also explained. Although that librarymodule is new to me.
There is a shortcut, which is generally to be frowned upon (tldr will make it slower to crawl over data analytically later), but maybe sometimes appropriate: JSON.stringify your object and store it in a normal key as a string.

member_string = JSON.stringify member
redis_client.set 'your_key', member_string
# something like that
# if your object is already flat then you can (just):
redis_client.hmset 'hash_key', member
# something like that, been awhile

[stockholmux]

@abhinav76 It really depends on how you are accessing the data, but you'll likely want to access by your member_name, right? So, pull that into the key.

var member={member_name:'svf',address:'cvbjnk'};

client.hmset('members:'+member.member_name, member, function(err) { ... });

Later, if you want to get that hash and all the fields you'd do:

client.hgetall('members:svf', function(err,values) { ... });

You may also want to look into some sort of secondary store to keep track of all your member:* hashes - something like a redis set or list

[abhinav76]

thanks @kulicuu and @stockholmux .

[abhinav76]

My redis data looks like below:
now how can i update any of the fields in the this data?
@kulicuu @stockholmux


"{\"f_name\":\"\",\"profile\":{\"member_username\":\"nikhil371\",\"member_gender\":\"Male\",\"member_dob\":0,\"member_country\":\"\",\"state\":\"\",\"city\":\"\",\"hair_colour\":\"\",\"hairstyle\":\"\",\"eye_colour\":\"\",\"eyesight\":\"\",\"complexion\":\"\",\"height\":\"\",\"body_ENGINE\":\"\",\"exercise\":\"\",\"religion\":\"\",\"religious_beliefs\":\"\",\"education\":\"\",\"occupation\":\"\",\"annual_income\":\"\",\"ethnicity\":\"\",\"nationality\":\"\",\"languages\":\"\",\"diet\":\"\",\"smoke\":\"\",\"drink\":\"\",\"current_relationship_status\":\"\",\"preferred_relationship\":\"\",\"profile_tagline\":\"\",\"screened\":\"N\",\"photo_status\":\"None\",\"hidden\":\"N\",\"record_date\":0,\"update_date\":0,\"ip\":\"\",\"member_id\":10548,\"time_stamp\":0,\"photo_key\":\"\",\"profile_personality\":{\"member_username\":\"nikhil371\",\"feature\":\"xcvbnkm\",\"zodiac\":\"vbnim\",\"favorites\":\"qerrb\",\"motto\":\"cvbn\",\"irritated\":\"aguweihjok\",\"sexiest\":\"atwvyebuinmo\",\"good_evening\":\"ywsbciobnom\",\"like_to_do\":\"vdsfd371\",\"outgoing\":\"ev\",\"prefer_to\":\"ebvjnk\",\"record_date\":371,\"update_date\":372,\"profile_other_info\":{\"id\":10516,\"member_username\":\"nikhil371\",\"describe_yourself\":\"tyuh\",\"views\":371,\"admin_login\":\"\",\"screening_assigned_to\":\"\"}}}}"


[stockholmux]

@kulicuu If you used JSON.stringify, you'll need to use JSON.parse to de-serialize the data, update your field, then you'll need to re-write it to the same key with JSON.stringify. It's pretty wasteful both in terms of CPU and space-efficiency.

Using hashes, you can update a single field by doing something like this client.hset('my:key:name','member_gender','female'). If you used flat to un-nest your object, you could update a single filed with client.hset('my:key:name','profile_personality.member_username','asdf').

[kulicuu]

I agree it's to be frowned upon-- and thanks @stockholmux for elaborating on the discussion of why that is--, but it's worth mentioning it as a shortcut.

For context, here's something I wrote about 8 months ago. I have had to defer the major refactor which would have moved most of the models into Redis' Lua scripts.
https://github.com/Terebinth/britvic/blob/deprecated_version/server/models/user_iced.iced
(the variable d is the redis client)
Check out some of the other models too. @abhinav76

[abhinav76]

@stockholmux i tried to use flat and it gives me error: MAximum call stack size exceeded ..
do you have any idea about that?