Application level SQL performance is much different than the performance of the SQL query itself but rather how it has been designed to work in the application. Many of the items I will be addressing in this area is designing your application to make less queries thus improving scalability and likely performance. However, performance does not always equal scalability as the same with scalability does not always equal performance.

He looks at a few different topics like lazy connections, iterating queries, need-based selects, normalization and a few simple things that you can apply to every SQL your application uses to optimize it as much as possible.

Having promised it in the first post on how to do Group By in CakePHP I worked on an array() version for the group statement in Model::find() calls. So I implemented it.

His code shows the calls to find() the grouped information and accompanying unit test assertEquals calls to check that the results are correct. His examples show a few different ways to accomplish the same thing.

The previous article gave you an overview of the phpMyAdmin interface and functionality. It's now time to dive in further and learn how to construct and execute queries.

They show (complete with screenshots) how to use the GUI to build the different parts of your query - a simple SELECT statement with a join pulling together the customer information and their addresses.

Okay, so it turns out that the paginate() method that is used to generate the data that you (oddly enough) paginate through takes the same arguments as Model::findAll(). So, if you want to use your own query, you simply create a 'paginate' method for your model.

His queries show the two parts of the equation - fetching the paginated results themselves and grabbing what the current page number is (like "page 7 of 23").

The method which we used to count number of friends of a specific user who has added that application was returning 1 when there is no friend actually installed it.

He gives the SQL query and the PHP code he was originally using to find out the number of users for the application. The problem came from the fact that the returning value wasn't an array - it was a string. The corrected code (that checks for array-ness) is also included.

Perhaps you have already heard of C# 3.5's "LINQ" component. LINQ, or Language Integrated Query, is a component inside the .NET framework which enables you to perform queries on a variety of data sources like arrays, XML, SQL server, ... These queries are defined using a syntax which is very similar to SQL. [...] I thought of creating a similar concept for PHP. So here's the result of a few days coding.

The library is available for download and some examples are included to show it in action (both in a simple example and in a more complex search on a series of objects).