PHP and MySQL
Two Useful Tools You Can’t Live Without
by Jenny Mitchell
SJSU CS157B Section 1
09-21-04
SJSU CS157B Dr. Lee
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 2004 Jenny Mitchell
Putting Our Knowledge to Use
• We are learning about databases, now
what can we do with that knowledge?
• Oracle
– Large download and installation
– Most of us used Oracle 9 in 157A
• MySQL
– Small download or use from web server
– Same SQL syntax, run from command line
or other application
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About MySQL
•
•
•
•
•
•
GNU Free, open-source, multi-platform
Implements the standard SQL language
Relational DBMS
Written in C and C++
Uses MyISAM B-tree disk tables
Uses in-memory hash tables for
temporary tables
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MySQL.com
• Developer Zone: Downloads and Documentation
• Available for Linux, Windows, Solaris, FreeBSD,
and more
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MySQL Installation
• Download 4.0 binary packages
• Check installation documents to see
what is automatically installed where
• Add appropriate aliases and users
• First start up in safe mode and test
default tables
• Run from shell or application
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MySQL Terminal Example
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MySQL Terminal Example
In-Class Demo
Insertion
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Building On MySQL
• What languages can we use for
building an application on MySQL?
– ODBC Connector
– JDBC Connector
– .NET Connector
– Web scripting languages
• PHP, ASP, JSP
SJSU CS157B Dr. Lee
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PHP
• PHP: Hypertext Processor
• Open source scripting language for web
developers to write dynamically
generated webpages
• Can download and install source and
binaries from www.php.net
• Need your computer to act as a server
– Apache, Tomcat are free downloads
SJSU CS157B Dr. Lee
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Basic PHP Scripting
• Syntax similar to C and JavaScript
• Not a compiled language, interpreted
– You don’t know where an error is until you try to
run it, and even then the line number doesn’t
always tell you where the actual error is
• Same logical structure - if/else, for, while
• Variables have no type declaration
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Hello, World!
<?php
$world = true;
if ($world)
echo(“Hello World!”);
else
echo(“Hello Nobody”);
?>
SJSU CS157B Dr. Lee
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Hello Nobody
<?php
$world = false;
if ($world)
echo(“Hello World!”);
else
echo(“Hello Nobody”);
?>
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Uses of PHP and MySQL
• Anything in a MySQL database can be
viewed on a webpage
• Any information which can be captured
from a website can be stored into a
database
FORMS
SJSU CS157B Dr. Lee
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Connecting to MySQL from PHP
/* Connection */
$username = ‘user’;
$password = ’password';
$webhost = 'localhost';
$db = ’test';
// username
// password
// host (localhost or something on a web server)
// the database
$dbc = mysql_connect($webhost, $username, $password) or die("<p>Could not
connect: <i>" . mysql_error());
@mysql_select_db($db) or die("<p>Could not find database - $db - <i>" .
mysql_error() . "</i>");
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Queries and Results
/* Perform SQL query and catch data */
$query = "SELECT * from t1 WHERE email != ‘’ ORDER BY name
ASC";
$result = mysql_query($query) or die("<p>Query failed: <i>" .
mysql_error() . "</i>");
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Displaying Results
$num = (int)@mysql_num_rows($result);
echo “<table border=2 cellspacing=3>”;
echo "<tr><td><b>ID</b></td><td><b>Name</b></td><td><b>Email</b></td></tr>";
for ($i = 0; $i < $num; $i++)
{
$line = mysql_fetch_array($result);
echo "<tr>";
echo "<td>" . $line[id] . "</td>";
echo "<td>" . $line[name] . "</td>";
echo "<td>" . $line[email] . "</td>";
echo "</tr>";
}
echo "</table>";
/* Housekeeping */
mysql_free_result($result);
mysql_close($dbc);
SJSU CS157B Dr. Lee
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Selection and Variables
• SQL Query statements can be built over
time
• PHP variables can be used in SQL
Query statements
• Variables can be generated based on
input form values
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Selection and Variables Code
HTML FORM CODE
<form method=post action=testinputquery.php>
<p>Enter a column name by which to sort: <input type=text size=8 maxlength=8 name=column>
<p><input type=Submit value=Submit name=Submit><input type=Reset value=Reset>
</form>
SQL PROCESSING CODE
/* Gather data from form variable */
$column = $_POST['column'];
/* Perform SQL query to catch data */
$query = "SELECT * from t1 WHERE email != '' ORDER BY $column ASC";
$result = mysql_query($query) or die("<p>Query failed: <i>" . mysql_error() . "</i>");
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Selection and Variables
In-Class Demo
Data Mining from Forms
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Insertion with Forms
• Create form with all input variables you
want, submit action to someform.php
• PHP script grabs all “post”ed variables
in the form
$var = $_POST[‘var’];
• Note that empty variables are the empty
string and not the null value
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Insertion with Forms Code
HTML FORM CODE
<form method=post action=testinsertion.php>
<p>Insert some data into this database</p>
<p><b>Name:</b> <input type=text name=name size=15 maxlength=20>
<p><b>Email:</b> <input type=text name=email size=15 maxlength=25>
<p><input type=Submit value=Submit name=Submit> <input type=Reset value=Reset name=Reset>
</form>
SQL PROCESSING CODE
/* Gather data from form variable */
$name = $_POST['name']; $email = $_POST['email'];
/* Perform SQL query to catch data */
$query = "INSERT INTO t1(name, email) values(\"$name\", \"$email\")";
mysql_query($query) or die("<p>Query failed: <i>" . mysql_error() . "</i>");
$num = mysql_affected_rows();
if ($num == '1')
echo "<p>Data was inserted successfully";
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 2004 Jenny Mitchell
Insertion with Forms
In-Class Demo
Inserting Data
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In Conclusion…
• MySQL - relational database package
which is free, small, easy to install
• PHP - dynamic scripting language
which is free, small, easy to install, and
automatically works with MySQL
• MySQL + PHP = affordable, portable,
easily accessible database backend &
application frontend
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 2004 Jenny Mitchell
What Are You Waiting For?
• http://www.mysql.com
• http://www.php.net
GO BUILD!
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