"In Chapter 8, "Designing Your Web Database, "we outlined how
web database architectures work. Just to remind you, here are the
A user's web browser issues an HTTP request for a particular
web page. For example, the user might have requested a search for
all the books written by Michael Morgan at Book-O-Rama, using an
HTML form. The search results page is called results.php.
The web server receives the request for results.php, retrieves
the file, and passes it to the PHP engine for processing.
The PHP engine begins parsing the script. Inside the script is
a command to connect to the database and execute a query (perform
the search for books). PHP opens a connection to the MySQL server
and sends on the appropriate query.
The MySQL server receives the database query, processes it, and
sends the results-a list of books-back to the PHP engine.
The PHP engine finishes running the script. This usually
involves formatting the query results nicely in HTML. It then
returns the resulting HTML to the web server. The web server passes
the HTML back to the browser, where the user can see the list of
books she requested.
"Now you have an existing MySQL database, so you can write the PHP
code to perform the preceding steps.Begin with the search form. The
code for this plain HTML form is shown in Listing