php_mysql_2006

Topeka, KS - High school sophomore Brett Tyson was suspended today after teachers
learned he may be using PHP.

"A teacher overheard him say that he was using PHP, and as part of our Zero-Tolerance

PHP and MySQL
policy against drug use, he was immediately suspended. No questions asked," said
Principal Clyde Thurlow. "We're not quite sure what PHP is, but we suspect it may be a
derivative of PCP, or maybe a new designer drug like GHB."

Parents are frightened by the discovery of this new menace in their children's school, and

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are demanding the school do something. "We heard that he found out about PHP at school
on the internet. There may even be a PHP web ring operating on school grounds," said
irate parent Carol Blessing. "School is supposed to be teaching our kids how to read and
write. Not about dangerous drugs like PHP."

Michael Coblenz In response to parental demands the school has reconfigured its internet WatchDog
software to block access to all internet sites mentioning PHP. Officials say this should
prevent any other students from falling prey like Brett Tyson did. They have also stepped
up locker searches and brought in drug sniffing dogs.

Interviews with students suggested that PHP use is wide spread around the school, but is
particularly concentrated in the geeky nerd population. When contacted by BBspot.com,
Brett Tyson said, "I don't know what the hell is going on dude, but this suspension gives
me more time for fraggin'. Yee haw!"

PHP is a hypertext preprocessor, which sounds very dangerous. It is believed that many
users started by using Perl and moved on to the more powerful PHP. For more information
on how to recognize if your child may be using PHP please visit http://www.php.net.
1 2

Introductions The Metadata

2 parts, each 3 hours
Me PHP ﬁrst, MySQL second
You End at lunch today
Continue tomorrow

3 4

The Rules Why are we here?
Think before you code! Want sites that change - dynamic sites.

Don’t just copy code from here Need more power!

No wimps! Powerful sites need powerful tools

This class is hardcore The tool makes the developer

Don’t get lost!
Questions are required, not optional

5 6

Our Example Static vs. Dynamic Sites

Static: stays the same
Might be edited periodically
An online store!
Dynamic: changes on demand
search, change preferences, interact, post, edit

7 8

What is PHP? Why a database?

Software package Need to store lots of data!
www.php.net Fast access to data
Works with web server software Data must persist
Similar to: ASP, ColdFusion, Java Server Pages (JSP) Data is structured

9 10

How Static Pages Work How Dynamic Pages Work
www.foo.edu
Hard Drive HTTP server (e.g. Apache, IIS) SQL query PHP
"Please process
MySQL "Here is an HTML ﬁle index.php."
query for index.php."
result
Database server (maybe
HTTP request: www.foo.edu)
I want index.html. GET index.html HTTP server (Apache)
index.html I want index.php.

GET index.php

User’s computer
User’s computer

11 12

The Plan Down to business!
PHP today

MySQL today/tomorrow

Integration tomorrow Let’s learn PHP!

Project: online store! tomorrow

13 14

Really: What is PHP? PHP Language Intro
PHP: Hypertext Preprocessor Think: "I’m generating an HTML ﬁle."
Program to help server Two categories:
1. Run script (a program!) PHP code
Generate HTML HTML
2. Send HTML to HTTP server HTML gets sent to user directly
3. HTTP server sends HTML to user PHP code executed, output sent to user

15 16

Which witch is which? Statements
Code in PHP code consists of statements
Delimiters: Courier Semicolon-terminated
<?php
Exception: last statement
?>
<?php
Between delimiters: MUST be PHP code echo ("Hello, world!");
doStuff ();
Not between delimiters: MUST be HTML
echo ("Goodbye, world!");
?>
17 18

Delimiter Examples Hello, world!
Input Output A working example
Put this in hello.php in Sites folder
<?php printPi(); ?> 3.14159265359…
<HTML><HEAD>
printPi(); printPi(); <TITLE>Hello!</TITLE></HEAD>
<BODY>
<?php echo(40 + 2); ?> 42 <?php echo ("Hello, world!");?>
</BODY></HTML>
40 + 2 40 + 2
Look at <server>/~josti#/hello.php
19 20

Spot the syntax errors Variables
< ?php echo ("hi") ?> Name preceded by $

<?php echo (hi) ?> No declarations, very weak typing

<?php echo ("hi") Must begin with letter or underscore

echo ("hi") ?> Names contain only letters, numbers,
underscores
<?php echo (""hello!""); ?>
$name = "George";
use instead:
WARNING: undeﬁned variables have NULL
<?php echo (""hello!""); ?> value; can use without error!
21 22

Comments If statements
if ($grade > 64) {
Comment your code! echo ("You passed!");
Code is for people, not machines. }
else {
PHP does this; // ignores this echo ("What a loser!");
/* PHP ignores }
Curly braces only required for more than one
all of this */ statement

23 24

More tests Handy Boolean operators
Greater than >
Not !
if ($grade >= 64 && !($grade > 75)) Less than <
echo "lucky punk!";
And && Greater than or equal to >=
if (calculateMeaningOfLife() == 42)
Less than or equal to <=
echo "Phew!";
Or ||
Not equal <>

25 26

Not syntax errors...
Spot the errors Loops
or "What does this code do?"
for ($i = 0; $i < $max; $i++)
if (name == "Dave") echo "D"; {
if ($name = "Dave") echo "D"; echo ("iteration " . $i);
}
if ($foo < 6); echo "less!"; Notice the "." - it’s the string concatenation operator.
if (1 < 4) while (isMoreData()) {
if (5 > 42) echo "one"; printData();
else echo "two"; }

27 28

Exercise Functions to Know & Tell
die("You lose! No data
Create a web page that displays your name 500 times. for you!");
mail($toAddress,$subject,
use a for loop.
$message, $headers);
After that works, modify it to also print a line number on isset($variable);
each line. But how do I read the documentation?
We'll see later.

29 30

Arrays Tables refresher (HTML)
Actually ordered maps <TABLE BORDER="1">
<TR>
keys (strings or ints) to values (stuff in <TD>100</TD>
array) <TD>200</TD>
<TD>300</TD>
$arr = array (5 => 1); </TR>
<TR>
echo $arr[5]; // 1 <TD>400</TD>
<TD>500</TD>
$arr["x"] = 42; remember this for MySQL <TD>600</TD>
</TR>
echo $arr["x"]; // 42 </TABLE>
31 32

Generating tables Questions?
<TABLE>
<?php
$rows = 10; $cols = 3;
for ($i = 0; $i < $rows; $i++) {
echo "<TR>";
for ($j=0; $j < $cols; $j++) {
Next up: Form processing
echo "<TD>row $i,col $j</TD>";
}
echo "</TR>";
}
?>
</TABLE>
33 34

Forms The Form
<FORM action="processor.php"
method="post">
<INPUT type="text" name="username"
Two parts
size="20"/>
form (HTML) <INPUT type="password"
name="password" size="20"/>
form processor (PHP) <INPUT type="submit" value="click
here!"/>
</FORM>
35 36

The form processor
<FORM action="processor.php" method="post">
<INPUT type="text" name="username" size="20"/>
<INPUT type="password" name="password" size="20"/>
<INPUT type="submit" value="click here!"/>
</FORM> Input fields are variables (PHP magic!)

Method: how browser sends data use $_POST["variable"] if sent with post.

GET $_GET["variable"] for get.
POST Changed in PHP 4.2 for security.
Action: where browser sends data Do whatever is appropriate with them.
INPUT: a field for data entry Query a database, perhaps?
Can be the same file as the form
37 38

A simple login system Exercise
<?php
if ($_POST["username"] == "teacher" &&
$_POST["password"] == "goldfish") {
echo ("Here are the grades."); Make a form for users to enter their name and favorite color.
}
If their favorite color is the same as yours, print something
else {
echo ("You lose!"); special.
}
?>

39 40

One page forms PHP include/require

<?php
if (isset($_POST["username"])):
Avoid code duplication
echo ("Hello, $_POST[username]"); include ("header.php");
else:
?> require ("login.php");
<FORM ...>....</FORM> Notice the colons! Same, but require fails if its arguments doesn’t exist.
<?php endif; ?> Avoids ugly echos.

41 42

Handling login Cookies
Or: angering ignorant users in one easy step!

Save a little data on user’s machine
Problem: each page wants $username, $password.
Like, say, the username, once they authenticated.
Solutions?
setcookie ("username", $username);
Yes, you.
Be more careful if you care about security.

43 44

How can login work?

require ("login.php");
in login.php: if username not set, ask and die. On to MySQL!
That’s it!
Not very secure. There are better ways.

45 46

What is SQL? What is MySQL?
Structured Query Language Particular implementation of SQL
Not English, Spanish, French,... Others:
Query: request SQLite (included in PHP 5)
"Please add Joe to the user list." PostgreSQL
"Who posted today?" MS SQL Server

47 48

MySQL includes... Relational Databases
mysqld
Daemon - runs all the time
Server process
Manages ﬁles that contain actual database Not your mother’s databases!
Database == spreadsheet?
mysql
Client - runs when you need it
Talks to mysqld

49 50

A good database? A Better Database
Mug Color Price ID Color ID Mug Price Color

Apple White $10 0 Apple 10 0
0 White
Microsoft Black $2 1 Microsoft 2 1
1 Black
Sun Green $5 2 Sun 5 2
2 Green
DEC green $100 3 DEC 100 2
Colors Mugs
51 52

Relational Databases Buzzwords
Table: Spreadsheet
Avoid Duplication
Database: Collection of tables
Assign a UNIQUE ID to each row
Row or record: Entry in table
Refer to data in other tables by ID
Column: Field for entering data
Unambiguous!
Schema: A particular database setup

53 54

Types Some data types
INT: -2147483648 to 2147483647
Think "kinds"
FLOAT, DOUBLE
Types of tools: hammer, screwdriver
DATE, TIMESTAMP
bang (hammer)? OK.
VARCHAR(20): up to 20 characters
turn (screwdriver)? OK.
TEXT: up to 65,535 characters
turn (hammer)? No!
BLOB: like TEXT, but sorting is case insensitive

55 56

Your turn! Using MySQL
Design a database schema for a store for your mug
collection. Use mysql client to talk to server
Hint: ssh (with PuTTY). See blackboard.
mugs table Login: josti#. Password: international
users table (better record who bought what!) mysql -u josti# -p
What data do you need? Now: only type MySQL commands.
Groups of three
57 58

MySQL commands CREATE TABLE mugs (id INT
NOT NULL AUTO_INCREMENT,
PRIMARY KEY (ID),
description VARCHAR(40),
use josti#; price float);
End commands with semicolons Pattern: create table <table_name> (column
Case InSenSiTiVe definition, column definition, ...)
show tables; Column definition: <column_name> <type>

59 60

Changing table schemata Indices and Keys

Index: pre-sort by this, so searching is MUCH faster

ALTER TABLE mugs ADD quantity Primary key: unique identiﬁer
int Constraints are your friend!
NOT NULL, DEFAULT

61 62

Adding Data Getting data
INSERT INTO mugs You SELECT the data you want FROM the table it's in.
(description, price) SELECT description, price FROM
values ('DEC', 100); mugs
or: INSERT INTO mugs SET SELECT description FROM mugs
description='DEC', ORDER BY description ASCENDING
price=100; SELECT description FROM mugs
Add a few records of your own! WHERE price < 10

63 64

A brief syntax interlude INSERT [LOW_PRIORITY |
DELAYED] [IGNORE] [INTO]
tbl_name [(col_name,...)]
VALUES ({expr |
"In the beginning there was the word. But by the time the DEFAULT},...),(...),...
second was added to it, there was trouble. For with it came [ ON DUPLICATE KEY UPDATE
syntax..." —John Simon col_name=expr, ... ]
"Colorless green ideas sleep furiously." - Noam Chomsky [stuff]: stuff is optional
Let’s look at the manual. {a | b}: pick a or b, not both. Must have
one.

65 66

ALTER [IGNORE] TABLE tbl_name
alter_specification [, alter_specification] ...

alter_specification:
More SQL
ADD [COLUMN] column_definition [FIRST | AFTER col_name ]
| ADD [COLUMN] (column_definition,...)
| ADD INDEX [index_name] [index_type] (index_col_name,...)
| ADD [CONSTRAINT [symbol]] PRIMARY KEY [index_type]
(index_col_name,...)
UPDATE mugs SET price=15
| ADD [CONSTRAINT [symbol]] UNIQUE [index_name] [index_type]
(index_col_name,...)
WHERE id = 1
| ADD [FULLTEXT|SPATIAL] [index_name] (index_col_name,...)
| ADD [CONSTRAINT [symbol]] FOREIGN KEY [index_name]
UPDATE mugs SET
(index_col_name,...) [reference_definition]
Oops! D
| ALTER [COLUMN] col_name {SET DEFAULT literal | DROP DEFAULT}
on't do
description='hello, world'
| CHANGE [COLUMN] old_col_name column_definition [FIRST|AFTER
col_name]
this!
| MODIFY [COLUMN] column_definition [FIRST | AFTER col_name]
| DROP [COLUMN] col_name
DELETE FROM mugs WHERE id
| DROP PRIMARY KEY
| DROP INDEX index_name
= 42
| DROP FOREIGN KEY fk_symbol
| DISABLE KEYS
| ENABLE KEYS ... (it keeps going!)
Try it yourself

67 68

Multiple tables mugs: description, id, color
colors: name, id

Problem:
And you thought it was complicated enough!
Combine data from two tables
mugs table: description, id, color
Attempted Solution:
but color is an int
SELECT mugs.description AS name, colors.name AS color
colors table: name, id
FROM mugs, colors
Want list of mugs and their colors
Does this work?

69 70

Wrong answer! Analysis
+------+---------+
+------+---------+ | desc | color |
+------+---------+
| desc | color | | DEC | Blue |
| Sun | Blue |
+------+---------+ A subset is | DEC | White |

| DEC | Blue | shown here MySQL followed instructions. | Sun | White |
+------+---------+

| Sun | Blue | for
simplicity.... SELECT mugs.description
| DEC | White | AS name, colors.name AS
| Sun | White | color FROM mugs, colors
+------+---------+
Got all combinations of mugs and colors!
What happened?
71 72

previously: SELECT

The Fix mugs.description AS name,
colors.name AS color FROM
mugs, colors
SQL functions
SELECT 1 + 2
SELECT MAX (price) FROM
What didn’t we specify? mugs
SELECT mugs.description AS name, MAX is an "aggregate" function
colors.name AS color also COUNT
FROM mugs, colors SELECT name FROM users
WHERE mugs.color = colors.id WHERE age < 18 OR age > 65
SELECT name FROM users
WHERE name LIKE ‘Mi%e%"
73 74

User accounts MySQL interface
New! Need PHP 5, MySQL 4.1
Object-oriented
Have a users table. The plan:
Store passwords. 1. Close anything you open
2. Open connection
No! Use sha1! 3. Do query
4. Use results

75 76

Using results Secret Forms
<TABLE>
<?php
$mysqli = new mysqli ("localhost", "josti#",
Scenario: How do you buy a mug?
"inter", "josti#");
if (mysqli_connect_errno())
Want "buy" link on entry...
echo "connect error!";
$result = $mysqli->query("SELECT * FROM mugs");
but link, not form
while ($row = $result->fetch_assoc()) {
echo "<TR><TD>$row[description]</TD> <TD>
Need to hide data in link
$row[price]</TD></TR>";
}
GET to the rescue!
?> (never seen GET in a cape and tights?)
</TABLE>
77 78

Secret forms: the trick! The project: a store!
1. Display all mugs for sale.
Need to encode post ID in link 2. Add a "buy" link next to each mug.
http://.../showMugs.php?mug=42 1. When clicked: go to a "complete purchase"
...?mug=42&sortBy=date&order=0 page
3. Add an "inventory" ﬁeld to the mugs table so you
Use urlencode($uglyStuff);
can track how many are in stock.
e.g. "Thing with spaces & stuff" 4. It should subtract one from the inventory every
hence ...?foo%20%37bar%20+baz time someone buys one.
5. Starter code is provided.
79 80

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