two useful tools you can’t live without by jenny mitchell sjsu cs157b section 1 09-21-04

SJSU CS157B Dr. Lee 1 2004 Jenny Mitchell

Two Useful Tools You Can’t Live Without

by Jenny MitchellSJSU CS157B Section 1

09-21-04

PHP and MySQL


• 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

Putting Our Knowledge to Use


• 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

About MySQL


• Developer Zone: Downloads and Documentation• Available for Linux, Windows, Solaris, FreeBSD,

and more

MySQL.com


• 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

MySQL Installation


MySQL Terminal Example


In-Class Demo

Insertion

MySQL Terminal Example


• What languages can we use for building an application on MySQL?– ODBC Connector– JDBC Connector– .NET Connector– Web scripting languages

• PHP, ASP, JSP

Building On MySQL


• 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

PHP

http://www.php.net/


• 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

Basic PHP Scripting


<?php

$world = true;

if ($world)

echo(“Hello World!”);

else

echo(“Hello Nobody”);

?>

Hello, World!


<?php

$world = false;

if ($world)

echo(“Hello World!”);

else

echo(“Hello Nobody”);

?>

Hello Nobody


• 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

Uses of PHP and MySQL


/* Connection */

$username = ‘user’; // username

$password = ’password'; // password

$webhost = 'localhost'; // host (localhost or something on a web server)

$db = ’test'; // 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>");

Connecting to MySQL from PHP


/* 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>");

Queries and 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);

Displaying Results


• 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

Selection and Variables


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>");

Selection and Variables Code


In-Class Demo

Data Mining from Forms

Selection and Variables


• 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

Insertion with Forms


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";

Insertion with Forms Code


In-Class Demo

Inserting Data

Insertion with Forms


• 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

In Conclusion…


• http://www.mysql.com

• http://www.php.net

What Are You Waiting For?

GO BUILD!

http://www.mysql.com/

http://www.php.net/

two useful tools you can’t live without by jenny mitchell sjsu cs157b section 1 09-21-04

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