Fastest way making records unique in a huge PostgreSQL table

I am currently working on a project were we are collecting huge amount of data. Recently we discovered that millions of rows were not unique. Because we are using Machine Learning to find patterns in the data and to cluster it, these dublicate rows were polluting the results of the learning algoritme. Therefor we had to come up with a solution to remove all dublicates and prevent new dublicates in the future.

Continue reading

How to Configure a Self Referencing Entity in Code First

Recently I was working on a project that required a categorization option. I wanted the user to have the option to create categories and as many subcategories as they wanted. To realize this I created a category model that was self referencing:

Continue reading

Some cool CSS stuff

css3-markupAfter my article about frontend development  where I particular focused on tools and javascript I will now focus more on CSS and styling. I can still remember the time when I started with web development and I used only inline styles. Now this is absolutely not done anymore. And that is very understandable considering that CSS has grown into a mature styling language nowadays and you don’t want to put all these logic in your html code.

Continue reading

Cross Domain Ajax with Cookies support using jQuery

Ajax requests are only possible when the protocol, domain and port number are the same. But sometimes you want to do Ajax calls to a different domain for example when you are creating a shared service that people should be able to call using Ajax or when you are developing locally and you are testing on a remote server. There are multiple ways to get around this restriction for example by using  CORS, an iFrame or JSONP. In my last project I got around the restriction using JSONP, so I will explain that here. See links for more information about solving it using CORS.

Continue reading

Floating point and Culture issues

Recently I was working on a ASP.NET MVC application where users could add budgets. The budgets were saved as floats. The problem was that some users used a (.) as decimal and others a (,). It depends on which culture setting your application is running if ModelState.isValid is true or false in such case. The culture setting in which your application runs depends on the system on which it is running. This is not a desired behaviour. Its better to specify the culture in the application itself and force users to use a (.) or (,). To run an ASP.NET MVC application in a specific culture setting you can add the following code to your Global.asax file:

More information:
http://stackoverflow.com/questions/19905694/c-sharp-mvc-4-model-changing-floating-point