The SitePoint PHP blog has continued their series showing the use of the PINQ library for PHP (a PHP implementation of the LINQ tool). In part one they introduced the tool and showed how to it could be used to query and sort data. In this second part they move on and show how to perform a multi-faceted search on data from a MySQL database.

We are not going to cover the full aspect of faceted search in this series. Interested parties can refer to relevant articles published on Sitepoint and other Internet publications. [...] Unfortunately, faceted search is not a built-in feature provided by MySQL yet. What can we do if we are using MySQL but also want to provide our users with such a feature? With PINQ, we’ll see there is an equally powerful and straightforward approach to achieving this as when we are using other DB engines – at least in a way.

Building from the code from the first part of the series, they create a few more simple routes that let you define the different facets to use for the searching/sorting. He creates a custom facet class that uses the "traversable" handling of the PINQ to do the data manipulation. He creates a few different facet objects, each creating a customized filter. finally, he ties it all back into the endpoint and includes the updated markup to show the results. He finishes up the post mentioning a few limitations and improvements that could be made on the example as well.

The SitePoint PHP blog has posted the first part of a new series they're releasing about querying your data with Pinq. It's a PHP-based query tool that provides a fluent interface for searching and traversing your data. In this first post of the series Taylor Ren introduces you to the library and shows some basic usage.

You may have heard of LINQ (Language-Integrated Query), a “set of features introduced in Visual Studio 2008 that extends powerful query capabilities to the language syntax of C# and Visual Basic”. It provides necessary interfaces and syntax to perform various queries on a given dataset so that operations like filtering, sorting, grouping, aggregating, etc can be performed. PINQ (PHP Integrated Query) is “based off the .NET’s Linq, and unifies querying across arrays/iterators and external data sources, in a single readable and concise fluent API”.

He talks about normal searching (equals matching) and "faceted searching", narrowing down the results piece by piece until you find what you need. He gives an example with some sample database data and shows the results of a simple query with a price filter and grouped by author. He includes the code to make it happen (inside a simple Silex application) too. He then takes a deeper look at the LINQ queries and how related statements are handled.

Code duplication is a common problem for developers. It's easy to copy and paste code around your application, but you're asking for trouble. Unfortunately, this kind of problem also extends to unit tests. In this new post to his site James Fuller looks at one way to help with this - using the @dataProvider to limit the repetitive data sets across tests.

PHPUnit offers a handy annotation called @dataProvider which can be used for all sorts of handy testing situations. Typically you will use this to feed in a wide variety of data into the same test to ensure that the system-under-test can handle a variety of inputs. Over time I have discovered a few other neat uses for dataProvider methods that I want to share with you today.

He provides some code samples showing how to use the dataProvider in a few tests, setting up an "allowed word" example. He gets a bit more complex with another test that takes in multiple parameters to "mix colors". In his last example he shows a data provider that converts names from camelCase to user_scores.

On PHPMaster.com today there's a new tutorial showing you how to test your application's interface with the database using "bulletproof" PHPUnit testing.

There's already a great article here that discusses Test Driven Development, but did you know that you can also test the code that interacts with your database? Especially if your application is data intensive, subjecting your CRUD code to a battery of tests is good practice that helps ensure that your application is working correctly. In this article you will be learning how to write database tests in PHP using PHPUnit and its database extension.

Included in the post is an example schema and an example of the seed data (defined as XML) for the testing to use as predictable data in its execution. His test class extends PHPUnit_Extensions_Database_TestCase (instead of the usual PHPUnit_Framework_TestCase) and a test for a basic "getArticles" method in his "IArticleDAO" class. By calling the "createXMLDataSet" method, the test loads in the pre-defined XML records and allows the correct evaluation of the assertions,

On the IBM developerWorks site today there's a new tutorial showing you how to store shared data directly to a shared memory space of your PHP application.

Once created, and given proper permissions, other processes in the same machine can manipulate those segments by: read, write, and delete. This means that an application written in C can share information with an application written in other languages, such as Java or PHP. They can all share information, as long as they can access and understand that information. [...] This article's proposal is simple, learn how to create and manipulate shared memory segments with PHP and use them to store datasets that other applications can use.

Your PHP installation will need to have been compiled with "enable-shmop" to work with the code in this tutorial. Their examples show how to use the shmop_open, shmop_write and other related functions to read, write, remove and close segments in the shared memory space. They also include an example of using the SimpleSHM library to make it easier to interact with the shared memory space as a standard storage location.

PHPmaster.com has a new introductory tutorial for those just starting out with PHP (or with programming really) talking about using looping structures for sets of data - for, while/do-while and foreach.

A significant advantage of computers is that they can perform repetitive tasks easily and efficiently. Instead of writing repetitive code you can write a set of statements that processes some data and then have the computer execute them repeatedly by using a construct known as a loop. Loops come in several different flavors in PHP: for, while, do-while, and foreach. I'll introduce you to each of them and show you how they can making repetitive tasks straightforward and easy to maintain.

The tutorial explains a use case for each of the loop types and includes a bit of sample code showing how to put it into practice. It also shares two special keywords that can be used to bypass or break out of your current loop - break and continue.

Martin Sikora was working on an application that used a large dataset (in an array) and found some interesting things in regards to PHP's resulting loading time and saving time in four different types of arrays.

Recently I was dealing with precessing and storing large arrays in PHP (around 100 000 items) and I found out some quiet surprising facts that are very useful in performance critical applications. [...] When I started looking for some benchmark I found article Cache a large array: JSON, serialize or var_export?. That is really good but I wanted to compare a few more things.

He tested with four different array types including associative with an integer value and numeric index with a string value at sizes of 10, 100, 1,000 and 10,000 items. He ran his tests with the json methods, serializing them and a var_export. There's graphs of his results for each included in the post with some interesting variations between the different array types.

In a new post Fabien Potencier looks at the ternary operator in PHP and wonders which is faster - using it or not (well, sort of...)

People like micro-optimizations. They are easy to understand, easy to apply... and useless. But some time ago, while reviewing pull requests for Twig, I read an interesting discussion about the performance of the ternary operator in PHP (thanks to @nikic for the investigation). Do you know which [example] snippet is the fastest (of course, they do exactly the same)? The right answer is: it depends.

He notes that it's all about the data being worked with. As some of his tests show (testing code included) there does end up being a difference between using it on a small and large dataset. After investigation, it was found that the ternary operator copies (copy-on-write) the value versus an "if" that just evaluates. He also mentions the new "?" version of the ternary syntax in PHP 5.3, but notes it still suffers from the same issue.

In a recent post to the MySQL Performance Blog, there's a pointer to a few resources you can use if you need some sample datasets to run your application against - everything from airline flight information to energy usage data.

Sometimes you just need some data to test and stress things. But randomly generated data is awful - it doesn't have realistic distributions, and it isn't easy to understand whether your results are meaningful and correct. Real or quasi-real data is best. Whether you're looking for a couple of megabytes or many terabytes, the following sources of data might help you benchmark and test under more realistic conditions.

The sample data sets vary from fake movie information to sample site traffic data to the large data sets that Amazon provides (including the Human Genome and US Census data). Some of the comments also link to other sources.

Paul Reinheimer has a reminder shown in his latest post about optimizing your scripts - don't forget the basics like unset.

A colleague called me over today for some help with a memory usage issue in his PHP script. The script was performing the basic (but critical) task of importing data, pulling it in from MySQL in large chunks, then exporting it elsewhere. He was receiving the wonderful "Fatal error: Allowed memory size of XXXX bytes exhausted (tried to allocate YY bytes)" error message. [...] I fixed the memory usage exceeded problem with an unset(), at the end of a loop.

The loop was structured such that the large amounts of data were just being held in memory over and over again, resulting in a huge stackup that can easily cause the "Allowed memory size exhausted..." message.

There are better architectures available to avoid the issue entirely (like not storing everything in the array, just to iterate over it later) but they're an issue for a different post. For a very simple base case demonstration of the issue take a look at the simple example.