so I developed a small Neo4j database with the aim of providing users with path-related information (shortest path from A to B and properties of individual sections of the path). My programming skills are very basic, but I want to make the database very user-friendly.
Basically, I would like to have a screen where users can choose start location and end location from dropdown lists, click a button, and the results (shortest path, distance of the path, properties of the path segments) will appear. For example, if this database had been made in MS Access, I would have made a form, where users could choose the locations, then click a control button which would have executed a query and produced results on a nice report.
Please note that all the nodes, relationships and queries are already in place. All I am looking for are some tips regarding the most user-friendly way of making the information accessible to the users.
Currently, all I can do is make the users install neo4j, run neo4j every time they need it, open the browser, run the cypher script and then edit the cypher script (write down strings as locations) and then execute the query. This makes it rather impractical for users and also I am worried that some user might corrupt the data,
I'd suggest making a web application using a web framework like Rails, especially if you're new to programming. You can use the neo4j gem for that to connect to your database and create models to access the data in a friendly way:
https://github.com/neo4jrb/neo4j
I'm one of the maintainers of that gem, so feel free to contact us if you have any questions:
neo4jrb#googlegroups.com
http://twitter.com/neo4jrb
Also, you might be interested in look at my newest project called meta model:
https://github.com/neo4jrb/meta_model
It's a Rails app that lets you define via the web app UI your database model (or at least part of it) and then browse/edit the objects via the web app. It's still very much preliminary, but I'd like to be able to things like what you're talking about (letting users examing data and the relationships between them in a user friendly way)
I general you would write an tiny (web/desktop/forms-)application that contains the form, takes the form values and issues the cypher requests with the form values as parameters.
The results can then be rendered as a table or chart or whatever.
You could even run this from Excel or Access with a Macro (using the Neo4j http endpoint).
Depending on your programming skills (which programming language can you write in) it can be anything. There is also a Neo4j .Net client (see http://neo4j.com/developer/dotnet).
And it's author Tatham Oddie showed a while ago how to do that with Excel
Related
I am trying to define a user management and permissions model for Neo4j. I have a web application (Angular 2) that connects to Neo4j via an API (KOANEO4J). Neo4j is the only database or persistent storage that the application uses. Through the application a user can add/edit/delete content which uses the API to carry out these instructions in Neo4j by running Cypher Statements. Up to now I have not worried about supporting multiple users but as a next step I am starting to think about this.
The product will be used by multiple different companies and each company will have multiple users so I need some way to support this. The model I am considering in Neo4J is as follows:
An "Orgaization" is represented by a node and it can have 1 or more "Organization Catalogs". All of the nodes belonging to that catalog will be children of one of the "Organization Catalogs".
Each user will also be represented by a node in the database. They will belong to an Organisation. They will have certain access permissions on an Organization Catalog identified by a an edge.
I am looking for some advice on whether or not this is an appropriate model to follow or if there are any examples or documents that describe how to achieve this in Neo4j.
If I do implement this model then would it be better to model the permissions as seperate nodes so a user is connected to a permission node (e.g. Read Only Access) that is then connected to the Organization Catalog.
Any suggestions on how I would actually get the API to work with this type of model. I'm sure I can pass the User Id to Neo4j as part of each query and then filter the results to show only nodes the user has access to but this doesn't seem like a very elegant solution - it also means that all of the security would be dependant on carefully written Cypher queries that don't leak data that a user isnt supposed to access.
Thanks a lot
I am looking for some advice on whether or not this is an appropriate
model to follow or if there are any examples or documents that
describe how to achieve this in Neo4j.
The answer for this question is: it depends. Remember that when modelling a graph database you should consider the queries that are asked to the database. If this model fits the queries that you are asking to the database then this model is appropriated, otherwise, not. Take a look in the Chapter 5 (Graphs in the Real World) of the book Graph Databases (by Ian Robison, Jim Webber and Emil Eifrem. Available for download here). This chapter shows the modelling process of an Authorization and Access Control system in Neo4j. Can be enlightening and helpful to you.
If I do implement this model then would it be better to model the
permissions as seperate nodes so a user is connected to a permission
node (e.g. Read Only Access) that is then connected to the
Organization Catalog.
Again, it depends. Do it if the Permission entity has connection to others entities of your application besides an User and an Organization Catalog. Otherwise I believe that your permission can be modeled as a relationship between an user and an organization catalog.
Any suggestions on how I would actually get the API to work with this
type of model. I'm sure I can pass the User Id to Neo4j as part of
each query and then filter the results to show only nodes the user has
access to but this doesn't seem like a very elegant solution - it also
means that all of the security would be dependant on carefully written
Cypher queries that don't leak data that a user isnt supposed to
access.
Maybe is a good idea add another layer of software between your AngularJS client app and the Neo4j database. This way in this new layer of software (a Node.js application, for example) you can implement a access control system, then verifiy if the authenticated user can access the resource that is being requested.
I need to do something like:
Show list of countries >> Select country -> show list of Cities.
So I have to get a list of cities by country but without using data in database.
Can anyone please suggest me a solution ?. I really appreciate your help.
You could use an API but the problem is that you will have a request everytime your page load. Not every API provider will allow this. For example, Here is an API that gets Country / Cities.
Another solution as you are using .NET technologies is to use a localDB. A localDB is in fact a database but within your app. Have a look to the definition on the MSDN :
It is very easy to install and requires no management, yet it offers the same T-SQL language, programming surface and client-side providers as the regular SQL Server Express. If the simplicity (and limitations) of LocalDB fit the needs of the target application environment, developers can continue using it in production, as LocalDB makes a pretty good embedded database too.
Finely, the last solution that comes in mind if you can't use XML or JSON files nor a LocalDB is to have your lists in classes but in my opinion you should avoid this solution, it will simply load everything in RAM until you application stops, as HDD cost less that RAM I really think the better option is to use XML or JSON files in your app.
You can store the info into a text file or even into a static class in your code (not exactly a great idea, but doable).
Then you just need to get the info from the container and build two SelectList items, one for countries and one for cities.
Use javascript to link change event of countries SelectList to a filtered reload of cities SelectList
Assuming you have a preset list of cities by country, and you really cannot use any sort of database, then perhaps just use text files? One text file for the list of countries and then one file per country with the list of cities. Read in the text file and display as needed.
From what I have read via google, it may be possible to do this with Rails? But I sadly don't know where to begin.
I have been asked to understand if it is possible to either utilising SQL Server or multiple CSV dumps to create a PDF of customer sales orders for the year.
An example of data I am working with is as follows;
What I need is a way to go through each ClientID in turn, Create a new page for each 'Category' Type of purchase as separate sequentially numbered PDF's so that Page 1 for client A1 would only have the motorcycle, page 2 would have the two helmets as that then completes that data entry for the client. I would need to save the two PDF pages as a single document entitled A1 and save this to C:\PDFOrderCreation
Constraints:
There can be no more than 10 lines of data per page,
There is a header and footer which have to remain static on the page(s)
I don't know where to begin with this, I have considered trying to do it with word but it would I think be extremely messy and resource heavy.
Anyone have any thoughts or able at least to push me in the right direction?
you would have to write a software that queries your SQL server and creates pdf files. There are many ways to do this, but afaik it cant be done using only SQL server features, SQL server is meant to store and serve your data, what you want to do with this data is out of it's scope. your software would have to do 3 things:1. To query the data from your server 2. To organize the data in the structure you need it to be presented 3. To write it to pdf filesYou would have to target each task individually, and it can be done using either a web application or a native application which could be written in ruby, c#, java, js,c++, objective c or any other programming language. Its important to note that TSQL is NOT a programming language, its a query language. Good luck!
I have an application that has different data sets depending on which company the user has currently selected (dropdown box on sidebar currently used to set a session variable).
My client has expressed a desire to have the ability to work on multiple different data sets from a single browser simultaneously. Hence, sessions no longer cut it.
Googling seems to imply get or post data along with every request is the way, which was my first guess. Is there a better/easier/rails way to achieve this?
You have a few options here, but as you point out, the session system won't work for you since it is global across all instances of the same browser.
The standard approach is to add something to the URL that identifies the context in which to execute. This could be as simple as a prefix like /companyx/users instead of /users where you're fetching the company slug and using that as a scope. Generally you do this by having a controller base class that does this work for you, then inherit from that for all other controllers that will be affected the same way.
Another approach is to move the company identifying component from the URL to the host name. This is common amongst software-as-a-service providers because it makes sharding your application much easier. Instead of myapp.com/companyx/users you'd have companyx.myapp.com/users. This has the advantage of preserving the existing URL structure, and when you have large amounts of data, you can partition your app by customer into different databases without a lot of headache.
The answer you found with tagging all the URLs using a GET token or a POST field is not going to work very well. For one, it's messy, and secondly, a site with every link being a POST is very annoying to work with as it makes navigating with the back-button or forcing a reload troublesome. The reason it has seen use is because out of the box PHP and ASP do not have support routes, so people have had to make do.
You can create a temporary database table, or use a key-value database and store all data you need in it. The uniq key can be used as a window id. Furthermore, you have to add this window id to each link. So you can receive the corresponding data for each browser tab out of the database and store it in the session, object,...
If you have an object, lets say #data, you can store it in the database using Marshal.dump and get it back with Marshal.load.
I'm starting a MongoDB project just for kicks and as a chance to learn MongoDB/NoSQL schemas. It'll be a live chat app and the stack includes: Rails 3, Ruby 1.9.2, Devise, Mongoid/MongoDB, CarrierWave, Redis, JQuery.
I'll be handling the live chat polling/message queueing separately. Not sure how yet, either Node.js, APE or custom EventMachine app. But in regards to Mongo, I'm thinking to use it for everything else in the app, specifically chat logs and historical transcripts.
My question is how best to design the schema as all my previous experience has been with MySQL and relational DB schema's. And as a sub-question, when is it best to us embedded documents vs related documents.
The app will have:
Multiple accounts which have multiple rooms
Multiple rooms
Multiple users per room
List of rooms a user is allowed to be in
Multiple user chats per room
Searchable chat logs on a per room and per user basis
Optional file attachment for a given chat
Given Mongo (at least last time I checked) has a document limit of 4MB, I don't think having a collection for rooms and storing all room chats as embedded documents would work out so well.
From what I've thought about so far, I'm thinking of doing something like:
A collection for accounts
A collection for rooms
Each room relates back to an account
Related documents in chats collections for all chat messages in the room
Embedded Document listing all users currently in the room
A collection for users
Embedded Document listing all the rooms the user is currently in
Embedded Document listing all the rooms the user is allowed to be in
A collection for chats
Each chat relates back to a room in the rooms collection
Each chat relates back to a user in the users collection
Embedded document with info about optional uploaded file attachment.
My main concern is how far do I go until this ends up looking like a relational schema and I defeat the purpose? There is definitely more relating than embedding going on.
Another concern is that referencing related documents is much slower than accessing embedded documents I've heard.
I want to make generic queries such as:
Give me all rooms for an account
Give me all chats in a room (or filtered via date range)
Give me all chats from a specific user
Give me all uploaded files in a given room or for a given org
etc
Any suggestions on how to structure the schema efficiently in a way that scales? Thanks everyone.
I think you're pretty much on the right track. I'd use a capped collection for chat lines, with each line containing the user ID, room ID, timestamp, and what was said. This data would expire once the capped collection's "end" is reached, so if you needed a historical log you'd want to copy data out of the capped collection into a "log" collection periodically, but capped collections are specifically designed for logging-style applications where you aren't going to be deleting documents, and insertion order matters. In the case of chat, it's a perfect match.
The only other change I'd suggest would be to maintain uploads in a separate collection, as well.
I am a big fan of mongodb as a document database aswell. But are you sure you are using mongodb for the right reason? What is mongodb powerful at?
Its a subjective question but for me in-place (atomic) updates over documents is what makes mongodb powerful. And I can't really see you using it that much. And on top of that you are hitting the document size limit problem aswell.(With experience I can tell you that embedding files to mongodb is not a good idea). You want to have a live chat application on top of database too.
Your document schema's seems logical. But I wouldn't go with mongodb for this kind of project where your application heavily depends on inserts. I would go for CouchDB.
With CouchDB you wouldn't have to worry about attachments problem, you can embed them easily. "_changes" would make your life much much easier to eighter build a live chat application / long pooling / feeding search engine (if you want to implement one).
And I saw an open source showcase project in couchone. It has some similarities with your goals: Anologue. You should check it out.
PS : Sorry it was a little off topic but I couldn't hold myself.