MongoDB get last 10 activities -


in social network want feed member a , member a following lets 20 category/member.
when category/member(followed member a) activity inserted collection called recent_activity :

{    "content_id": "6", // content id member following    "content_type_id": "6",// content type (category , other member)    "social_network_id": "2", // action category did (add/like/follow)    "member_id": "51758", //member    "date_added": isodate("2014-03-23t11:37:03.0z"),    "platform_id": numberint(2),    "_id": objectid("532ec75f6b1f76fa2d8b457b"),    "_type": {      "0": "altibbi_mongo_recentactivity"    }  }

i want when member a login system last 10 activities categories/member

my problem :

how 10 activities categories/members.

it better in 1 query or loop.

for use case, i'd suggest invert logic , keep separate object of last 10 activities member kept up-to-date time. while solution more write-heavy, makes reading trivially simple , can extended easily. i'd blatantly advertise blog post wrote while ago news feeds mongodb outlines approach.

this 'fan-out' approach might seem overly complex @ first, when think importance filtering / ranking (a la facebook), push messages particularly important events (facebook, twitter) or regular digest emails (practically all), 1 location in code perform logic.


Comments

Post a Comment

Popular posts from this blog

android - Get AccessToken using signpost OAuth without opening a browser (Two legged Oauth) -

i using signpost oauth access data magento server. have read various tutorials on same , reach point open browser user can enter credentials. however, per requirement have automate part. hence, user should not browser page. have set-up done on server side ( magento ), hit url , returned call page. same through program in android. i have tried below, consumer = new commonshttpoauthconsumer(key, secret); provider = new commonshttpoauthprovider(oauth_init_url,access_token_url, authorize_url); try { provider.retrieverequesttoken(consumer, oauth.out_of_band); log.d("tokens" , consumer.gettoken() + " -- " + consumer.gettokensecret()); } and request tokens. dont know how bypass next step. tried directly accessing accesstoken (stupid of me) provider.retrieveaccesstoken(consumer, "mycallback://callback"); no luck, ends in oauth.signpost.exception.oauthnotauthorizedexception: authorization failed (server replied 401). ...
Read more

org.mockito.exceptions.misusing.InvalidUseOfMatchersException: mockito -

getting error org.mockito.exceptions.misusing.invaliduseofmatchersexception: invalid use of argument matchers! 1 matchers expected, 2 recorded. exception may occur if matchers combined raw values: //incorrect: somemethod(anyobject(), "raw string"); when using matchers, arguments have provided matchers. example: //correct: somemethod(anyobject(), eq("string matcher")); at when( getprogramservice .callservice(any(getprogramtype.class))) .thenreturn(jaxbresponse); please explain error , possible resolution the code posted looks fine; don't see problem it. code before or above causing exception. key here: invalid use of argument matchers! 1 matchers expected, 2 recorded. any , used above, doesn't return "special kind of null" or "special kind of getprogramtype"; don't exist. instead, returns null , side effect puts matcher on stack. whe...
Read more

google shop client API returns 400 bad request error while adding an item -

i'm working on solution add items in google shopping market java application. following tutorial real mess because of missing classes of laste release, after setting 1.5-beta maven managed make base example typecheck correctly classes. still can make simple task of adding 1 item. instead of posting whole code i'm posting part creates product feed. private product createproduct(string id) { product product = new product(); product.title = "red wool sweater"; product.content = new content( "text", "comfortable , soft, sweater keep warm on " + "cold winter nights. red , blue stripes."); product.appcontrol = new appcontrol(); product.appcontrol.addrequireddestination("productads"); product.externalid = id; product.lang = "it"; product.country = "it"; product.condition = "nuovo"; product.price = new price("eu...
Read more