Mongodb aggregate to find if a user is in any other user's follower list -

-

i collected followers list , friends list n number of users twitter , stored them in mongodb.

here sample document:

{   "_id": objectid("561d6f8986a0ea57e51ec95c"),   "status": "true",   "userid": "1489245878",   "followers": [     "1566382441",     "1155774331"   ],   "followerscount": 2,   "friendscount": 5,   "friends": [     "1135511478",     "998082481",     "565321118",     "848123988",     "343334562"   ] }

i wanted know within collection, there userids in followers list of other documents. lets have user "a", know if user "a" in followers list of other document within same collection. i'm not sure how this. in case if have, project userid , _id of document has userid within followers list.

i guess can use aggregate function below result.

db.getcollection('your_collection").aggregate([   {     "$match": {       "followers": "1566382441"     }   },   {     "$project": {       "followers": 1     }   },   {     "$unwind": "$followers"   },   {     "$match": {       "followers": "1566382441"     }   },   {     "$group": {       "_id": "$followers",       "ids": {         "$addtoset": "$_id"       }     }   },   {     "$project": {       "userid": "$_id",       "ids": 1,       "_id": 0     }   } ])

i using sample of data. can add list of users whom trying filter in both stages of "$match". see if helps.

p.s: know been long time since asked question! know, never late!


Comments

Post a Comment

Popular posts from this blog

javascript - Chart.js (Radar Chart) different scaleLineColor for each scaleLine -

-
Image
i try , create radar chart using chart.js has various colours each scaleline, or coloured between scalelines. wondering if possible? from: to: i have working graph, though there doesn't seem method change individual scale lines. kind regards leigh you can extend radar chart type this, so chart.types.radar.extend({ name: "radaralt", initialize: function (data) { chart.types.radar.prototype.initialize.apply(this, arguments); var originalscaledraw = this.scale.draw; var ctx = this.chart.ctx; this.scale.draw = function () { var linewidth = this.linewidth; // bypasses line drawing in originalscaledraw this.linewidth = linewidth; originalscaledraw.apply(this, arguments); ctx.linewidth = this.linewidth; var scale = this; // draw chart.helpers.each(scale.ylabels, function (label, index) { // color of ...
Read more

apache - Error with PHP mail(): Multiple or malformed newlines found in additional_header -

-
suddenly have started receiving above error without changes having been made script. host 1and1 (i know...) the script still works fine on different server, , suspicion there must have been server config change has lead this, although hosts plead ignorance. there's no information on above error @ in google can find - have ideas? server running apache if helps. had similar problem. came out of blue. no php code changed. what changed: php upgraded 5.5.25-1 5.5.26. a security risk in php mail() function has been fixed , newlines in additional_headers allowed no more. because newlines mean: starts email message (and surely don't want inject newlines through headers followed evil message). what have worked fine, e.g. having newlines after headers or passing whole message additional_headers , function no more. solution : sanitize headers. no multiple newlines in additional_headers argument. these count "multiple or malformed newlines":...
Read more

java - Android – MapFragment overlay button shadow, just like MyLocation button -

-
Image
i'm struggling add shadow custom overlay button on google map. goal make custom button google's mylocation button. here's how app looks now: layout.xml <relativelayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:map="http://schemas.android.com/apk/res-auto" android:layout_height="match_parent" android:layout_width="match_parent" style="@style/apptheme"> <fragment android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/map" tools:context=".mapsactivity" android:name="com.google.android.gms.maps.supportmapfragment" android:layout_alignparentend="true" android:layout_alignparentstart="true" android:layout_alignparentbottom="true" ...
Read more