If
you’re already familiar with PHP for database backed web-applications, you’re
probably also familiar with LAMP, O’Reilly’s acronym for the hugely popular
Linux/Apache/MySQL/PHP stack of software. For you then to jump to Oracle will
be a small step, as you’ll simply have to learn some new calls that make up the
oci8 library. If you’re new to PHP as well, there’s a bit more to learn, but
we will point you on the right track to get you started with the basics, and
links to resources that’ll help you go further.
What is PHP?
PHP
has one of those recursive names, PHP Hypertext Preprocessor. It was
originally designed around web programming, but has since evolved to be a
full-fledged scripting language like Perl. So for instance by adding #!/usr/bin/php
to the top of a file, you can invoke the php processor for programs that are
never called from a web server. Far and away the strength of PHP is in its
community, and how it has evolved. Rather than being designed at the outset to
be everyone’s ideal language and framework, PHP has evolved a huge base of
developers, and libraries of functions that people needed in the real world.
PHP
is used everywhere on the internet, from high traffic sites like facebook.com
to popular blog publishing software like wordpress. It is also rock solid,
currently at release 5.2.6.
PHP
executes with embedded code snippets in your HTML. So for instance the old
famous "hello world" example could be done as follows:
<HTML>
<BODY>
<?php
echo “<B>Hello World</B>”;
?>
</BODY>
</HTML>
Of
course, inside that code section you can be doing all sorts of other things
like connecting to a database, sifting through data, formatting it, and sending
it back to the user as a nicely formatted HTML page in their browser.
Connecting with Oracle
In
the MySQL space, the technology stack is called LAMP. In the Oracle space it’s
called OPAL, Oracle, PHP, Apache & Linux. You can talk to Oracle a few
different ways; there are some database abstraction libraries like PDO or ADOdb.
These allow you to build database independent code.
However,
if you want the full power and performance of Oracle, you should use the OCI8
libraries.
# note to the parser that we have php code coming next
<?php
# Here’s how we connect:
$dbh = oci_connect (‘sean’, ‘hull’, ‘seansdatabase’);
# Here’s how we pass an sql statement:
$stmt = oci_parse ($dbh, ‘select fname, lname from accounts’);
# Here we execute the statement:
oci_execute ($stmt);
$cnt = 1;
# Then we fetch rows in a loop until we’re done
while ($result = oci_fetch_array($stmt)) {
echo “user: ” . $cnt . ” ” . $result[’fname’] . ” ” . $result[’lname’] . “<br>”;
$cnt = $cnt +1;
}
# last we close the database handle
oci_close($dbh);
# and note to the parser that this is the end of the php code section
?>
Object Oriented & Other Features
PHP
also now supports a whole host of object oriented features, if that suits your
fancy. You’ll find abstract classes for prototyping, use of the final classes
to prevent further subclassing. PHP also supports overloading, thus multiple
functions with the same name but different parameters, allow the PHP
interpreter to choose which function to call at runtime. You’ll also find
private and protected member variables as well as constructors, and
destructors.
PHP
also has great exception handling with the TRY, CATCH & THROW syntax. An
example of how you might use this might be if you were going to perform a
division. You could put a TRY before it, then a CATCH section displaying an
error if you divide by zero.
Oracle’s Moves
Justin
Kestelyn & Chris Jones over at Oracle Technology Network have been building
their PHP
Developer Center for some time. There is a huge amount of support coming
from Oracle now. Just a quick look at the PHP page at OTN and you’ll see what
I mean.
You’ll
find everything from installation guides, to more advanced topics like
scalability and high availability. Even some podcasts as well. This is a really
great site for PHP + Oracle information.
Chris
Jones has also published "The
Underground PHP and Oracle Manual" so if there are any questions in
your mind, you’re sure to find the answers here:
Chris’
manual will give you everything from nuts and bolts details about drivers to
code examples, and plenty of details on getting you started. There are details
on installing Oracle XE, installing Apache, and installing PHP with various
drivers. You’ll find details for both Windows and Linux, and details on the
instant client installs as well. All in all, this manual is a treasure trove
of information for those building PHP applications on top of Oracle.
Conclusion
PHP
is a powerful language for building sophisticated web applications as well as stand-alone
scripts, which you can call from the command line. With a full compliment of
database support, specifically for Oracle, you are on very solid ground
building your web application with OPAL. What’s more, you’ll find tremendous
support from Oracle Corporation besides.
PHP
continues to grow in popularity and usage. If the number of user conferences
is any indication, that trend shows no signs of slowing.
»
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