PHP and ASP.NET Go Head-to-Head

When it comes to Web development these days, you have a lot of options. Many of these methods involve preprocessing—that is, embedding code into HTML pages with special tags that signal to a preprocessor that they contain code, and that it should do something with it. Much like a CGI, this code is then run on the server, and it returns some content, which then assumes part of the shape of the resulting HTML page sent back to the browser. Both the open source scripting language PHP and languages within Microsoft's ASP.NET framework fall into this category; JavaServer Pages (JSP) and Perl/Mason operate this way as well.

In this article I'll focus on PHP, the technology Oracle has chosen to incorporate into its products, and ASP.NET. I'll overview the various strengths and weaknesses of each, discussing in particular those areas that will help you make your decision on which to go with for your development project. There are a lot of factors to consider, and different projects may appeal to a different technology. In conclusion you'll find a point-by-point comparison in terms of price, speed and efficiency, security, cross-platform support, and the advantages of an open source solution.

What is ASP.NET?

The latest incarnation of ASP, ASP.NET, is not completely backward-compatible with previous versions of ASP, as it is a complete rewrite of the software. Previous ASP technology actually has a lot more in common with PHP than with ASP.NET, which is a complete framework for building Web applications. One of the principal features of this model is the flexibility to choose your programming language. ASP.NET works with scripted languages such as VBScript, JScript, Perlscript, and Python, as well as compiled languages such as VB, C#, C, Cobol, Smalltalk, and Lisp. The new framework uses the common language runtime (CLR); your language source is compiled into Microsoft Intermediate Language code, which the CLR then executes.

The framework also provides for true object-oriented programming (OOP), and true inheritance, polymorphism, and encapsulation are supported. The .NET class library is organized into inheritable classes based around particular tasks, such as working with XML or image manipulation.

Besides the programming language and the methodology, database access is a significant concern. When you program in ASP.NET, integration with databases can be accomplished through ODBC, which provides a consistent set of calling functions to access your target database.

Strengths and Weaknesses

ASP.NET's strength lies clearly in its clean design and implementation. It is an object-oriented programmer's dream, with language flexibility, and with sophisticated object-oriented features supported. In that sense, it is truly interoperable with your programmers' existing skills.

Another strength of ASP.NET is the development environment. For instance, developers can use WebMatrix, a community-supported tool, Visual Studio .NET, or various Borland tools such as Delphi and C++ Builder. Visual Studio, for instance, allows setting of breakpoints, tracing sections of code, and reviewing the call stack. All in all, it's a sophisticated debugging environment. Plenty of other third-party IDE solutions for ASP.NET are certain to surface as well.

But what you gain in robustness, you pay for in efficiency. ASP.NET is expensive with respect to memory usage and execution time, which is due in large part to a longer code path. For Web-based applications, these limitations can be a serious problem, because on the Web, your application is likely to scale to thousands and thousands of users per second. Memory usage can also become an issue on your Web server.

What is PHP?

PHP is a scripting language based on the model of preprocessing HTML pages. When the PHP preprocessor in your Web server notices a PHP language tag like the following, the PHP engine is invoked to execute that code:


some code here
?>


PHP will be familiar to any programmers who have worked with imperative programming languages; you'll notice syntactical similarities with Perl, C, and Java. Strictly speaking, Java is an imperative programming language, but it also makes use of object-oriented constructs and concepts. PHP borrows from this structure when it is convenient, but it is not a pure OOP language.

In the discussion of ASP.NET above, I mentioned the ODBC driver, and how applications can be built with database abstraction in mind. In PHP, you can also use ODBC to talk to databases, so you already have a whole list of supported databases to choose from. There are also native drivers for MySQL, Oracle, and Postgres. Furthermore, if you are connecting to Oracle, a special OCI8 library provides more feature-rich access to Oracle, allowing you to use such features as LOB, BLOB, CLOB, and BFILE.

You might ask, at this point, "Why are database-dependent libraries being touted as features of PHP?" Database abstraction, or independence, is a feature if you seek to build an application that works with multiple databases in one application or that can easily be ported to another database—when moving from development to production, for instance. And these are indeed valid concerns and considerations.

But, as Tom Kyte points out in his latest book, Effective Oracle by Design (Oracle Press), database dependence should be your real goal because you maximize your investment in that technology. If you make generic access to Oracle, whether through ODBC or Perl's DBI library, you'll miss out on features other databases don't have. What's more, optimizing queries is different in each database.

Zend Technologies, a commercial software company that contributes significantly to PHP, has created a commercial-development environment called Zend Studio that includes a sophisticated debugger, a profiler, and other features. It has also built the free Zend Optimizer, which, in combination with the Zend Encoder, compiles PHP code to speed performance. Additional commercial products also exist, such as the Zend Performance Suite, which can cache precompiled PHP pages, further speeding overall performance tremendously