NoSQL Databases

141

Solutions

284

Contributors

A NoSQL database provides a mechanism for storage and retrieval of data which is modeled in means other than the tabular relations used in relational databases. Motivations for this approach include: simplicity of design, simpler "horizontal" scaling to clusters of machines and finer control over availability. The data structures used by NoSQL databases (e.g. key-value, wide column, graph, or document) are specified from those used by default in relational databases, making some operations faster in NoSQL. Sometimes the data structures used by NoSQL databases are also viewed as "more flexible" than relational database tables.

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Dear Experts,

we have  back end application running on Cassandra and which has all our transaction data but we have a static data available in mysql
but i would like to know  if I would like to have queries between tables across two databases for the joins how that can be achieved.

Thanks
Roy...
0
Bootstrap 4: Exploring New Features
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Bootstrap 4: Exploring New Features

Learn how to use and navigate the new features included in Bootstrap 4, the most popular HTML, CSS, and JavaScript framework for developing responsive, mobile-first websites.

Connection Error: No Mongos proxy available.

Environment: Node.js, MongoDB, Mongoose

Start.js
const mongoose = require('mongoose');


mongoose.connect(process.env.DATABASE,  { useNewUrlParser: true })
mongoose.Promise = global.Promise;
mongoose.connection
  .on('connected', () => {
    console.log(`Mongoose connection open on ${process.env.DATABASE}`);
  })
  .on('error', (err) => {
    console.log(`Connection error: ${err.message}`);
  });

.env file

DATABASE=mongodb://username:DBpassword@player-shard-00-00-1cmur.mongodb.net:27017,player-shard-00-01-1cmur.mongodb.net:27017,player-shard-00-02-1cmur.mongodb.net:27017
0
How to use more than one percentage sign in queries in OrientDB?

For example : select from MyNode where MyNodeText.toLowerCase() like '%text1%text2%'
This does not work
0
I want to write a init script to stop and start the MongoDB.
0
Hi,
i am currently working on the task of Data Migration from 1 cassandra cluster table to another cassandra cluster table using spark batch job.

i need a spark code for reading data from one cassandra cluster table and to process it in spark and then write results onto another existing cassandra cluster table.
0
I know there's a ton of questions around date/time storage and formatting, but I'm struggling to get the right approach. My app is a Node.js app with Express using mongoose with a MongoDB backend. I'm using moment.js to format my date/times.

The schema in question looks like:

const stateSchema = new mongoose.Schema({
  changed: {
    type: Date,
    default: new Date()
  }
});

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Based on the docs, I was expecting the date to be stored in UTC by default, but instead I see this:
changed: 2018-08-15 17:26:14.499

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I'm displaying the date/time with something like (pug):

p= `Changed: ${moment(state.changed).format('MMMM Do YYYY, h:mm:ss a')}`

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On localhost, the app shows "August 15th 2018, 5:26:14 pm" but on the hosted Heroku app I get "August 15th 2018, 10:26:14 pm." I am expecting "August 15th 2018, 5:26:14 pm" because I'm opening the Heroku app in the same timezone, but it looks like it's giving me the server timezone.

What should I do to make sure the date/time shows up in the client's local timezone?
0
HI,
Need experts view on the following line  -
Most NoSQL solutions however are built with the assumption that the data does not fit on a single machine and hence have sharding builtin.

Is it that noSQL solutions have easier or better sharding capabilites than relational databased like mysql ?

And should one use noSQL always in case of sharding ?

Thanks
0
Hi,
suppose i have a mysql table  with rows (originalUrl : varchar(500) , shortUrl : varchar(10))
The queries that will be executed on this table will mostly be
1. select * from table where shortUrl = X
2. insert into table (originalUrl, shortUrl)

So there should be an index on shortUrl to speed this up.

I have the following question -
1. What exactly the index table will store ?
My understanding is index table will store items like - (shortUrl, pointerToDisk) // where pointerToDisk will locate exactly the place in disk where the row is stored.

2. Where is index table stored ?
Is it always stored in Disk or memory ?

3. What is the size of index table exceeds that of RAM ?
In this case the full index table will never be in RAM and so how will queries like select * from table where shortUrl = x execute
Will a part of index table be pulled out everytime to check the location ?

4. In case where this table is very huge say 3 TB. How big will index table be...

5. If index table is larger than size of RAM and since then the queries will take a lot of time. Is there a better alternative ?? Like using noSQL database. or storing data in two machines splitting them rather than on one machine ?

Thanks
0
{
 "_id" : "Sh",

"Name" : "HR",
"Form" : [
    {
        "Name" : "HR",
        "Permission" : {},
        "Fields" : [
            {
                "OutputFormat" : "Text",
                "Validation" : [],
                "Name" : "PASS",
                "Permission" : {
                    "Hidden" : [
                        "ac"
                    ]
                },
                "IsFormulaArg" : false,
                "MaxCharacters" : 100.0,
                "Label" : "PASS",
                "Widget" : "Dropdown",
                "DefaultPermission" : [],
                "Dropdown" : "me",
                "Score" : 1,
                "PermissionType" : "Hidden",
                "Id" : "me"
            },


            {
                "OutputFormat" : "dd/MM/yyyy",
                "NodeList" : {
                    "Score" : 2,
                    "Type" : "CellReference",
                    "Id" : "jdk2",
                    "Value" : null,
                    "CellMetadata" : {
                        "72uw" : "CreatedAt"
                    }
                },
                "Name" : "Date_Prepared",
                "Permission" : {},
                "IsFormulaArg" : false,
                "Required" : true,
                "Widget" : "Date",
                "Label" : "Date Prepared",
                "Score" : 2,
                "FormulaStr" : "CreatedAt",
                **"Formula" : "True",**
      …
0
I am trying to install MongoDB on my hosted Linux box and getting this error.

I cannot seem to get it corrected after trying many different forum solutions.

Anyone have any thoughts?

My hosted system specs:
Operating system Debian Linux 8
Kernel and CPU Linux 3.16.0-5-amd64 on x86_64

 The following packages have unmet dependencies:
 mongodb-org : Depends: mongodb-org-server but it is not going to be installed
               Depends: mongodb-org-mongos but it is not going to be installed
               Depends: mongodb-org-tools but it is not going to be installed
 unifi : Depends: mongodb-server (>= 2.4.10) but it is not going to be installed or
                  mongodb-10gen (>= 2.4.14) but it is not installable or
                  mongodb-org-server (>= 2.6.0) but it is not going to be installed
         Depends: mongodb-server (< 1:3.6.0) but it is not going to be installed or
                  mongodb-10gen (< 3.6.0) but it is not installable or
                  mongodb-org-server (< 3.6.0) but it is not going to be installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

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T.I.A.!
0
Introduction to Web Design
LVL 12
Introduction to Web Design

Develop a strong foundation and understanding of web design by learning HTML, CSS, and additional tools to help you develop your own website.

So i have a user schema like this:

var user_schema = new Schema({
   username:{type:String,required: true, unique : true, trim: true},
   college:{type:String,required: true},
   password:{type:String,required: true, trim: true},
   email:{type:String,required: true, unique : true, trim: true},
   phone:{type:Number,required: true, unique : true, trim: true},
   dp:{type:String},
   tag:{type:String},
   description:{type:String},
   friends:[{type:String}],
   pending:[{type:String}],
   skills:{type:String},
   bucket:[{type:String}]
  });

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and my objective is, to search the all the documents in the collection to get people based on the following conditions:

1. They should not be in the users' "friends" array.
2. They should not be in the users' "pending" array.
3. They should have the same "tag" (a string value) as the user.

So, basically I have to compare the users' fields ("friends","pending" and "tags"), with fields of all documents in the whole collection.

How do I do it, using mongoose (nodejs mongodb library)
0
I have to initialize an array to [](empty array) and then push user chose "tags" into it. This is my schema:

 var user_schema = new Schema({
   username:{type:String,required: true, unique : true, trim: true},
   college:{type:String,required: true},
   password:{type:String,required: true, trim: true},
   email:{type:String,required: true, unique : true, trim: true},
   phone:{type:Number,required: true, unique : true, trim: true},
   dp:{type:String},
   tags:[{type:String}],
   description:{type:String},
   skills:{type:String},
   bucket:[{type:String}]
 }); 

Open in new window

` and i have to initialize "tags" to [] and push user string values (user entered/chosen) every time the request is made to the API call.

I am using this line of code:

 stu_user.findOneAndUpdate(
   { _id: req.decoded.id },
   { $set:{tags:[]},$push: { tags: 'some chosen string'  } },
  function (error, success) {
         if (error) {
            console.log(error);
        } else {
            console.log(success);
        }
    });

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But it's not working.
0
How to import collections from mongodb from cli?
0
Hey, This is just a decision-making problem. I am seeking for a well thought out answer.
I have to develop an android XMPP chat application, (the application also has a NodeJS server API, connecting to MongoDB and AWS S3 for picture uploads)

which will be better:

1. Having a "openfire" server on aws and connecting it to the android application and implementing an XMPP client on the android device using "smack" library.

2. Implementing a "xmpp-client" on NodeJS server side and scrape the results from this API to the Android device.
0
I am new to Angular and Firebase. I created an app where I am using email user and pass auth with Firebase auth.  When the user registers with a user and pass, two additional fields are added and populated in Firestore (Display Name and photoURL).  Those are populated by code in the auth.services.ts file.  So, when a user logs in again, it authenticates but then writes the Display name and photoURL again into the FIrestore.  I want to be able to add (or let the user add) the Display name and photo after they are logged in.  Here is what I have so far.  Any thoughts or direction?

FirestoreDB
FirebaseDB
Code in auth.services.ts
Auth Services
0
How do MongoDB and Active Directory go together?

I have a small bit of exposure to MongoDB and  Active Directory as well. But is there so synergy of using them together?

Curious..

Thanks
0
Why are NoSQL databases so much faster than SQL databases?

I am curious about the steps needed todo something like insert a record for NoSQL versus SQL databases

I have never needed to understand what was under the covers on SQL Server, or any database. So I am curious about what step are simply removed by NoSQL

Thanks
0
I have a web application that uses ssrs 2016 for reports.  I am looking at moving the sql database to a nosql database, but don't know how to maintain the reports I have created.  Any ideas?
0
hi,

how DB2 work with MongoDB ?
0
Learn SQL Server Core 2016
LVL 12
Learn SQL Server Core 2016

This course will introduce you to SQL Server Core 2016, as well as teach you about SSMS, data tools, installation, server configuration, using Management Studio, and writing and executing queries.

In MongoDb collection a DateTime field is stored in MST dateTime format for over 1 millions of record for a older record and now new records in utc dateTime format,
  Is there any cost effective query to update the date property in collections for those old recordsin MST dateTime
  (update the registered date format from MST to UTC format i.e. update time + 7:00 hr of each of these record)? We have MongoDb 3.3 version.
0
I'm having difficulty putting a complex(to me) aggregation query together for my data. Basically, here's the run down so everyone understands my conundrum.

I have two collections in this equation. "training_documents" and "users". Each user object has a key identified by name "trainings" which is an array of objects. Each object within this trainings array, contains 4 key/value pairs. An example of each object is below.

    {
    	"document": ObjectId('5a0350ad7df0977d94cffab6'),
    	"trainee": ObjectId('59e51a4b7df0977d94cff95d'),
    	"trainer": ObjectId('595fcc2e04cf707693257890'),
    	"completion_time": "2018-04-23T21:28:22.747Z"
    }

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The users trainings array will contain many objects following the aforementioned format.

An example user data structure is below for reference.

   
 [
    	{
    		"_id": "5ad782283c55b056bcc39e3z",
    		"site": {
    			"site_id": "site1",
    			"site_name": "Site One"
    		},
    		"user_name": "jsmith",
    		"first_name": "John",
    		"middle_name": "A",
    		"last_name": "Smith",
    		"full_name": "John Smith",
    		"title": "Duh Boss...",
    		"email": "testuser@example.com",
    		"last_login": "2018-04-27T14:27:27.014Z",
    		"type": "full-time",
    		"active": true,
    		"__v": 0,
    		"badge_id": "000001780343232123",
    		"trainings": [
    			{
    				"document": ObjectId('5ae33622a766885a121b7362'),
    				"trainee": 

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0
hi,

what is the solution to integrate Oracle with Mongo DB? data flow between them ?
0
hi,

anyone know how to intergrate MariaDB and Mongo DB so that they work together well ?

how about MariaDB and hadoop?
0
hi,

anyone know how to intergrate MS SQL and Mongo DB so that they work together well ?

how about MS SQL and hadoop?
0
nodeJs and MongoDB
I Would like to  Create a dynamic navbar with mean stack a navbar that the admin can modify it navbar has
Main Categoy
Sub Categories title
sub category
example image https://prnt.sc/j3nxz7
0

NoSQL Databases

141

Solutions

284

Contributors

A NoSQL database provides a mechanism for storage and retrieval of data which is modeled in means other than the tabular relations used in relational databases. Motivations for this approach include: simplicity of design, simpler "horizontal" scaling to clusters of machines and finer control over availability. The data structures used by NoSQL databases (e.g. key-value, wide column, graph, or document) are specified from those used by default in relational databases, making some operations faster in NoSQL. Sometimes the data structures used by NoSQL databases are also viewed as "more flexible" than relational database tables.

Top Experts In
NoSQL Databases
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