First let me explain. My platform is mostly Windows and my data mostly resides in a relational database (SQL Server 2008). I primarily work with C# but occasuionally work with PERL and JavaScript. I was looking to learning what a graph database could do for my data but there seems to be a continual stream of tools and utilities that are not available that I need to install and learn. I am so busy learning the tools that I loose focus of what I really want and that is to work with a graph database.
It seems that Neo4j is relatively small and should be accessible to evaluate its features. I would like to import my data from an existing SQL database into Neo4J with the relationships established initially via the foreign keys. The idea seems relatively straightforward but it seems I need to learn Java, PHP, etc. not only to access Neo4J but also to access the existing database. I was wondering if anyone had some recommendations, tools, documentation that would accomplish this goal fairly simply. Do I do down the route of PHP? Java? What additional libraries/packages do I need? What tools are most useful? Thank you.
I think you want the Neo4J batch importer, which can be found on github. Using this, we were able to export 20 million nodes and relationships to import them into Neo4j.
I think you will have to write your own. Neo4jD looks interesting.
Related
For my small company I am trying to build a data input form for several departments that input data into SQL tables. I would like to give the user the ability to input data, update existing data, and see graphs of historical data that they have inputted.
I personally know VB.net but my IT head wants to use PowerApp. No one knows PowerApp in the company but he thinks it will be easier to use and implement/share across the company.
Is PowerApp easy to learn?
Can Power App input data into MS SQL?
In general, which is better for my intended use?
Thank you!
YMMV, but in general PowerApps is easier than a programming-language based platform for building apps. It won't be as powerful as the latter, but for the specific example that you mentioned (data input, presentation), it should be fine. Take a look at the documentation, especially in the section about creating an app automatically from your data (the link talks about apps from SharePoint, but the same works for SQL Server as well)
Yes, data integration is built in the platform, and SQL Server (both SQL Azure and on-premises installations of SQL Server) is supported
As always, it depends (which is why this question may be closed for being primarily opinion-based). A full-fledged programming language will always have more power than a "no-code/low-code" solution such as PowerApps, but if what you need to do is within the domain of that solution, it will likely be easier to implement. PowerApps also makes it easier to deploy the app in mobile devices (iOS / Android), which is not as easy to do with VB.NET, but again, that depends on your scenario.
Hi everyone I’m new to server-side technologies so maybe this is a bit of a dumb question but after reading dozens of articles and viewing dozens of videos I’m still very confused. This has to do with arquitecture principles of modern apps.
Relational model:
I know that a few years ago the model was to have a database (mostly relational) and a DBMS that enabled the connection between an app and the database.
Question 1: Since we are talking about a relational model some examples of DBMS’s are MySQL or PostgreSQL?
Question 2: What is the process of information exchange? The client-side uses a language like PHP to make a request to the server and then the DBMS transforms the request into SQL and accesses the database? Is the conversion of the PHP into SQL part of DBMS function or another server-side software is needed?
(If someone could provide me summary detailed explanation I would be very thankful)
Non-Relational Models:
Question 2: Nowadays with the rise of NoSQL models does the same concept of DBMS apply? Since these systems allow other querying language other than SQL there should be some piece of software that has this function?
Service Oriented Arquitecture:
Almost every app uses this type of arquitecture. I understand the concept of avoid the creation of too tight software relation between client and server side allowing for multiple use across several platforms. What I don’t understand is what parts constitute a system that is build this way.
Question 3: Does the DBMS provides the API’s that constitute the web services made available?
Web Frameworks:
Last but not least, where do frameworks like Django or Ruby on Rails land on?
Question 4: These are supposed to provide tools to develop everything between the front-end and the database of a SOA system right?
Question 5: I’ve seen a lot of buzz about REST arquitecture. Can you explain me of the querying process happens and what are the software entities involved.
Thank you in advance for any explanation that helps me understating these questions. Please provide some links or any diagrams that you find useful.
EDIT:
I'll tackle your questions individually:
Question 1: Since we are talking about a relational model some examples of DBMS’s are MySQL or PostgreSQL?
Correct. The Database Management System is the suite of software that lets you interact with a particular database technology. The examples you give are correct.
Question 2: What is the process of information exchange? The client-side uses a language like PHP to make a request to the server and then the DBMS transforms the request into SQL and accesses the database? Is the conversion of the PHP into SQL part of DBMS function or another server-side software is needed?
There are many different avenues for this. Typically the API for accessing a database is done via ODBC (Open Database Connectivity). ODBC drivers are available for most (if not all) Relational DB vendors and are all very similar.
A language like PHP could connect to the database via an ODBC connection library (eg http://php.net/manual/en/intro.uodbc.php) which would allow you to send CRUD operations to the DBMS to be executed on the database.
Since most DBMS's use a subset or superset of a SQL standard for querying the database you can either pass this code directly via ODBC or you may use another level of abstraction. A common method is called an ORM (Object Relational Mapper). ORMs (eg SQLAlcmehy for Python: http://www.sqlalchemy.org/) provides an abstraction layer so you're not reliant on writing SQL but instead write queries and database commands in a format more common of your language of choice.
Question 2: Nowadays with the rise of NoSQL models does the same concept of DBMS apply? Since these systems allow other querying language other than SQL there should be some piece of software that has this function?
Same general concept (in that there is a DB Driver that exposes an API that languages can hook into) but there are generally more and differing ways of interacting with DB's now since they have many differing structures. Most NoSQL DBs still have ODBC connectors (eg MongoDB and Hadoop) so the general programming practices still apply whilst connecting with them, but the things you expect the database to do (and their natural query languages) will differ.
This continues to be an evolving space as these technologies evolve.
Question 3: Does the DBMS provides the API’s that constitute the web services made available?
Not sure I'm understanding this question. ODBC and webservices are different. Often webservices sit on top of ODBC if you want to query a database via a web API, but it's one layer of abstraction more than connecting to the DB directly via ODBC.
Last but not least, where do frameworks like Django or Ruby on Rails land on?
Web Frameworks are a way of quickening the development of web applications by trying to stop some of the "reinvent the wheel" things that you commonly do with every web application. They give you the basics, and have a lot of extensions that allow you to implement other common elements of web apps (like a subscription/login system, session management, admin system etc).
These are supposed to provide tools to develop everything between the front-end and the database of a SOA system right?
Both Django and RoR aim to be end-to-end frameworks. They include all the common elements you'll need including an Object Relational Mapper. They don't prescribe which DBMS you have to use, their ORMs can interface with many so that choice is still up to you.
Yes, they are aimed to cover everything from the front end to the DB, including the interaction with and initialization of the structure of the database.
Question 5: I’ve seen a lot of buzz about REST arquitecture. Can you explain me of the querying process happens and what are the software entities involved.
REST stands for Representational State Transfer (quick Wikipedia article: https://en.wikipedia.org/wiki/Representational_state_transfer). In a nutshell the creation of a "RESTful" (REST compliant) web API would mean that you have GET, PUT, POST and DELETE methods to accomplish all your services. REST aligns closely with the HTTP protocol which is why it's been very appropriate for the ever growing concept of Web Apps, it's helped transform the thinking from a Web Page (or set of web pages) into Web Apps.
It's hard to sum up better than the Wikipedia article does, I'd suggest you dive into it.
Hope that's cleared up a few of the questions!
Looking for advice on web development languages/tools for a simple project. I have used HTML to create simple sites before but they were primarily just static information. I have no experience with web scripting, etc. at this point.
Our company has a half dozen or so Transact SQL queries that produce simple text reports from our SQL Server database. I would like to create a simple web type application so that users on our intranet can run these queries themselves vs. asking for what they need.
The queries require minimal input from the user. Typically they would only need to enter a start and stop date or a customer number, or an invoice number.
The application needs to be functional, not especially pretty. I want the user to be asked for the above type input as appropriate and then specify where a file with the reults should be written on their computer.
On other projects I have done some Python programming in conjunction with the SQL Server database, just nothing that interacts with a web site or that has a GUI.
Thank you in advance for your suggestions.
You'll very least need to know a server side language such as PHP or Python to make the queries. Maybe a CGI script?
Most commonly used, I believe, is PHP. It is well-documented and meant for the what you want to do, contrary to Python, which doesn't play as nice with HTML as PHP. As stated on the PHP website, it is quite popular and as such has quite a few tutorials online. After you understand the syntax - you said you have programmed in Python, so only the syntax would be new to you - you should look into how to connect with your SQL Server. Microsoft owns that, so I hope (for them) they explain it well enough: http://technet.microsoft.com/en-us/library/cc793139(v=sql.90).aspx. That should equip you with what is needed for what you describe in the question.
I found this question as well: Can PHP work with a MS SQL database. The accepted answer suggests you can use PDO as well to connect to SQL Server. I recommend PDO over the mssql_ functions, because it offers an object oriented API and and an API that makes prepared statements real easy, among others.
I am starting to delve into the realm of ORMs, particularly NHibernate in developing .NET data-aware applications. I must say that the learning curve is pretty steep and that a lot of things should be noted. Apparently, it actually changes the way you do data-aware applications, manner of coding, development and just about everything.
Anyway, I want to ask if you do set some parameters when deciding to USE or NOT TO USE ORMs in your applications? How do you decide then the approach that one needs to make it valuable to your organization?
The organization which I work for now apparently has made a lot of SQL and Data Access thing running through back end and I must say that these class/methods/procedures have successfully performed their tasks of providing the data which is needed and when it is needed. I think it would be a tremendous effort just to map some of this into ORM and derive the same business value that the company has for the last few years.
Nevertheless, I know that ORM paves the way for applications to talk with database servers, if properly implemented. I must admit that I am at a learning stage and that I would possibly need all the help, resources and the guidance to make this transition. I was also thinking of buying the book from Manning but I feel that with so much changes to NHibernate, the book may be a bit outdated. Perhaps waiting for the Packt book on NHibernate (release on May 2010??) would help me better get up and running.
Kindly share your thoughts. By the way, if you could also point me in a small sample web app which uses NHibernate + Visual Web Developer 2008 Express and SQL Server, that would be highly appreciated.
Thanks.
For me, the short of it is the following:
If you don't use an established ORM, and you develop correctly (meaning you refactor out duplication and look to simplify where you can), you'll wind up building your own ORM through the evolution of your data access layer.
The question then becomes:
"Do I want my developers spending time learning the idiosyncrasies of my home-grown ORM or learning those of a well-documented and well-tested ORM?"
Furthermore:
"If I'm hiring a new developer, wouldn't it be nicer to bring in a developer that knows the established ORM tool we're using rather than having to train someone up on this thing I built?"
I use NHibernate, particularly Fluent - and it's great; if given the choice, I wouldn't develop on an RDBMS any other way.
To be successful with an ORM you must make sure to normalize correctly, and use the database for it's designed purpose, storing data.
I don't use an orm when:
I don't use a relation database (Relational databases are not the best choice of database for every application)
The database is has a very small amount of tables. (I might need less code without an orm)
I use a very simple database that can map to code with simple naming
conventions. (Mapping to dumb DTO classes and all queries like select * from tablename where id=#id)
Learning a good orm is worth the time and effort, it will save you writing a lot of code when you use relational databases a lot.
You can find example apps/tutorials/video's about NHibernate on with stackoverflow search. There is another book in progress by manning, maybe it's possible to read it with the early access program.
I am developing a cocoa application that will be making heavy use of both web services and a standard dbms (most likely MySQL) and I am wondering if anyone has a good option for a database library or ORM solution they have used. CoreData is not an option due to the need to support a standard DBMS and to be able to modify the data outside of the normal application operation.
I have found a number of possible options from new open source libraries:
http://github.com/aptiva/activerecord/tree/master
To writing my own wrapper for the C MySQL api.
Any advice is welcome,
Thanks!
Paul
We faced a similar question when we first started work on Checkout, our solution was to code the entire app in Python, using PyObjC. Checkout 1 had an sqlite backend, Checkout 2 has a postgres backend.
There are a couple of really mature and powerful ORMs on the Pyton side, such as SQLObject, which is pretty simple to work with (we used it for Checkout 1.0) and SQLAlchemy, which is more powerful but a bit harder to wrap your brain around (we used it for Checkout 2.0).
One approach you could evaluate, is building the application in Objective-C, but writing the data model and database connectivity/adminstration code in Python. You can use PyObjC to create a plugin bundle from this code, that you then load into your app That's more or less the approach we took for Checkout Server, which uses a Foundation command-line tool to administer a postgres server and the databases in it, this CLI tool in turn loads in a Python plugin bundle that has all of the actual database code in it. End-users mostly interact with the database through a System Preferences pane, that has no clue what the database looks like, but instead uses the command-line tool to interact with it.
Loading a plugin is simple:
NSBundle *pluginBundle = [NSBundle bundleWithPath:pluginPath];
[pluginBundle load];
You will probably need to create .h files for the classes in your bundle that you want to have access to from your Obj-C code.
You might also want to check out the BaseTen framework. It is a Core Data-like framework (in fact, it can import Core Data models), but works with PostgreSQL (though not MySQL, as far as I know). It includes some very nice features such as schema discovery at run time. It also includes an NSArrayController subclass that automatically handles locking and synchronizing across multiple users, so you can continue to make use of Apples Key-value Binding in your UI.
I have personal experience with this particular problem. I even started down the road of writing my own wrapper for the C MySQL API.
The eventual conclusion was: Don't!
The solution that worked in my case was to communicate with the MySQL server via PHP. If you are familiar with web services, chances are that you know about PHP, so I don't won't go into loads of detail about that.
To read from the database:
The cocoa app sends a request for a URL on the server: http://theserver.com/app/get_values.php
The get_values.php script handles the database query, and returns the data in xml format
The cocoa app loads and parses the xml
To write to the database:
The cocoa app sends a more complex request to the server: http://theserver.com/app/put_values.php?name="john doe"&age=21&address=...
The put_values.php script parses the input and writes to the database
The beauty of this solution is that PHP is great for working with MySQL, and cocoa has some handy built-in classes for working with XML data.
edit: one more thing:
One of the key things you have to figure out with this approach is how much processing should be done on the server, and how much should be done in the app itself. Let cocoa do the things that cocoa is good at, and let PHP and MySQL do the things that they are good at.
You could write a generic PHP script to handle all queries: perform_query.php?querystring="SELECT * FROM .....", but that is hardly an optimal solution. Your best bet is several smaller PHP scripts that handle individual datasets for you. In my case, there was one to get the list of users, one to get the list of transactions, etc. Again, it all depends on what your app is going to do.
GDL2 is a nice example, based on EOF.
Instead of reinventing the wheel by writing your own communication wrapper to deal with MySQL from Cocoa, you could try the SMySQL framework (a.k.a. MCPKit), it was part of the CocoaMySQL application that evolved into the Sequel Pro project. It works with varying versions of MySQL, and seems to be quite robust.
If you need to understand how to incorporate it into your application, there's not much documentation around, but it has an easy to understand interface and you can see it working by looking at the source of Sequel Pro, which is downloadable from Google code.
There is also the CocoaMySQL-SBG fork of the CocoaMySQL project, but that seems to be out of date and I couldn't get it to build properly.
I've also implemented a simple object persistence framework based on sqlite, but it certainly wasn't trivial to do. I agree with eJames' conclusion- don't implement one yourself if you don't have to.
If you aren't committed to programming in Objective-C you might want to take a look at PyObjC which would allow you to program the database portion in Python. You can use the MySQLdb module for DB access and there are plenty of tutorials online for its use. It isn't hard to stuff the data back into Cocoa/CF classes and pass them back to your app.
The main caveat with PyObjC is that at the moment it doesn't work with Tiger.