Php and MySQL

PHP and MySql
Tiji Thomas
HOD
Department of Computer Applications
MACFAST
tiji@macfast.org

What is PHP?
PHP stands for PHP: Hypertext Preprocessor
PHP is a server-side scripting language, like ASP
PHP scripts are executed on the server
PHP supports many databases (MySQL, Oracle, Sybase,
PostgreSQL etc.)
PHP is an open source software

What is a PHP File?
 PHP files can contain text, HTML tags and scripts
 PHP files have a file extension of ".php"

A PHP scripting block always starts with
<?php
and ends with
?>.
A PHP scripting block can be placed anywhere in the
document.
<?php
?>
Example
<html>
<body>
<?php
echo "Hello World";
?>
</body>
</html>
Basic PHP Syntax

In PHP, we use // to make a single-line comment or /* and */ to make a
large comment block.
<html>
<body>
<?php
//This is a comment
/*
This is
a comment
block
*/
?>
</body>
</html>
Comments in PHP

Variables in PHP
All variables in PHP start with a $ sign symbol.
The correct way of setting a variable in PHP:
$var_name = value;
PHP is a Loosely Typed Language
In PHP a variable does not need to be declared before being set.

Variable Naming Rules
A variable name must start with a letter or an underscore "_“
A variable name can only contain alpha-numeric characters and
underscores (a-Z, 0-9, and _ )
A variable name should not contain spaces.

PHP OperatorsArithmetic Operators
1. +
2. -
3. *
4. /
5. %
6. ++
7. --
Assignment Operators
1. =
2. +=
3. -=
4. *=
5. /=
6. .=
7. %=

PHP Operators
1. ==
2. !=
3. >
4. <
5. >=
6. <=
Comparison Operators
Logical Operators
1. &&
2. ||
3. !

The Ternary Operator
It is called the ternary operator because it takes three
operands - a condition, a result for true, and a result for
false
<?php
$agestr = ($age < 16) ? 'child' : 'adult';
?>

Strings in PHP
Example
<?php
$txt="Hello World";
echo $txt;
?>

The Concatenation Operator
The concatenation operator (.) is used to put two string values together.
Example:
<?php
$txt1=“Department :";
$txt2=“of Computer Applications , UC College";
echo $txt1 . " " . $txt2;
?>

1. strlen()
The strlen() function is used to find the length of a string
<?php
echo strlen("Hello world!");
?>
2. strpos()
The strpos() function is used to search for a string or
character within a string
<?php
echo strpos("Hello world!","world");
?>

PHP Date()
Synatax:
date(format,timestamp)
Parameter Description
format Required. Specifies the format of the timestamp
timestamp Optional. Specifies a timestamp. Default is the current date and time
(as a timestamp)

The first parameter in the date() function specifies how to
format the date/time. It uses letters to represent date and
time formats. Here are some of the letters that can be used:
• d - The day of the month (01-31)
• m - The current month, as a number (01-12)
• Y - The current year in four digits
• l -A full textual representation of the day of the week (Sunday through
Saturday )
• F - A full textual representation of a month, such as January or March
(January through December
S-English ordinal suffix for the day of the month, 2 characters
(st, nd, rd or th)
PHP Date - Format the Date

<?php
echo date("Y/m/d");
echo "<br />";
echo date("Y.m.d");
echo "<br />";
echo date("Y-m-d");
echo "<br />";
echo date("D-M-Y");
echo "<br />";
echo date('l dS of F Y');
?>
Example - 23

Conditional Statements
if (condition)
code to be executed if condition is true;
else
code to be executed if condition is false
The If...Else Statement
Example -3
<html>
<body>
<?php
$d=date("D");
if ($d=="Fri")
{
echo "Hello!<br />";
echo "Have a nice weekend!";
echo "See you on Monday!";
}
?>
</body>
</html>

html>
<body>
<?php
$d=date("D");
if ($d=="Fri")
elseif ($d=="Sun")
echo "Have a nice Sunday!";
else
echo "Have a nice day!";
?>
</body>
</html>

The Switch Statement
switch (expression)
{
case label1:
code to be executed if expression = label1;
break;
case label2:
code to be executed if expression = label2;
break;
default:
code to be executed
if expression is different
from both label1 and label2;
}

<html>
<body>
<?php
$x = 1;
switch ($x)
{
case 1:
echo "Number 1";
break;
case 2:
echo "Number 2";
break;
case 3:
echo "Number 3";
break;
default:
echo "No number between 1 and 3";
}
?>
</body>
</html>
Example - Switch

1. Numeric array - An array with a numeric ID key
2. Associative array - An array where each ID key is
associated with a value
3. Multidimensional array - An array containing one or more
arrays
PHP Arrays

Numeric Arrays
A numeric array stores each element with a numeric
ID key.
There are different ways to create a numeric array
$names = array(“Raju",“Rajan",“Ramu");
$names[0] = “Raju";
$names[1] = “Rajan";
$names[2] = “Ramu";

Example
 <?php
 $names[0] = “Raju";
 $names[1] = “Meera";
 $names[2] = “Ramu";
 echo $names[1] . " and " . $names[2] .
 " are ". $names[0] . "'s neighbors";
 ?>

An associative array, each ID key is associated with a value.
$ages = array(“Tony"=>32, “Rony"=>30,
“Sony"=>34)
$ages[‘Tony'] = "32";
$ages[‘Rony'] = "30";
$ages[‘Sony'] = "34";
Example -8
<?php
$ages["Rony"] = "32";
$ages['Tony'] = "30";
$ages['Sony'] = "34";
echo “Tony is " . $ages["Tony"] . " years old.";
?>
Associative Arrays

Multidimensional Arrays
In a multidimensional array, each element in the main array can also
be an array. And each element in the sub-array can be an array, and
so on.

$families = array
(
“Thomas"=>array
(
“Roni",
“Toni",
“Soni"
),
“Joseph"=>array
(
“Jomy"
),
“Mathew"=>array
(
“Rani",
“Ramu",
“Reena"
)
);
print_r($families["Thomas"][2]);

Looping
 while - loops through a block of code if and as long as a
specified condition is true
 do...while - loops through a block of code once, and then
repeats the loop as long as a special condition is true
 for - loops through a block of code a specified number of times
 foreach - loops through a block of code for each element in an
array

The while Statement
while (condition)
{
code to be executed;
}
<html>
<body>
<?php
$i=1;
while($i<=5)
{
echo "The number is " . $i . "<br />";
$i++;
}
?>
</body>
</html>

The do...while Statement
The do...while statement will execute a block of code at least once - it
then will repeat the loop as long as a condition is true.
do
{
}
while (condition); <html>
<body>
<?php
$i=0;
do
{
$i++;
echo "The number is " . $i . "<br />";
}
while ($i<5);
?>
</body>
</html>
Example-12

For Statement
for (init; cond; incr)
{
}
<html>
<body>
<?php
for ($i=1; $i<=5; $i++)
{
echo "Hello World!<br />";
}
?>
</body>
</html>

Foreach Statement
foreach (array as value)
{
}
<html>
<body>
<?php
$arr=array("one", "two", "three");
foreach ($arr as $value)
{
echo "Value: " . $value . "<br />";
}
?>
</body>
</html>
Example-14

Sorting an array
<?php
$fruits = array("lemon", "orange", "banana",
"apple");
sort($fruits);
foreach ($fruits as $key => $val) {
echo "fruits[" . $key . "] = " . $val . "n";
}
?>

PHP Functions
Creating PHP functions
 All functions start with the word "function()"
 The name can start with a letter or underscore (not a
number)
 Add a "{" - The function code starts after the opening curly
brace
 Insert the function code
 Add a "}" - The function is finished by a closing curly
brace

Example -15
<html>
<body>
<?php
function writeMyName()
{
echo "Raju Thomas";
}
writeMyName();
?>
</body>
</html>

PHP Functions - Adding parameters

<html>
<body>
<?php
function writeMyName($fname)
{
echo $fname ."<br />";
}
echo "My name is ";
writeMyName(“Thomas");
echo "My name is ";
writeMyName(“Varghese");
echo "My name is ";
writeMyName("Tom");
?>
</body>
</html>

Function return values
<html>
<body>
<?php
function add($x,$y)
{
$total = $x + $y;
return $total;
}
echo "1 + 16 = " . add(1,16);
?>
</body>
</html>
Example-17

Form Handling
•A form is an area that can contain form elements.
•Form elements are elements that allow the user to
enter information (like text fields ,drop-down menus,
radio buttons, checkboxes, etc.) in a form.
•A form is defined with the <form> tag.

Form Handling In HTML
<form>
<input>
<input>
</form>
Input
The most used form tag is the <input>
tag. The type of input is specified with
the type attribute. The most commonly
used input types are explained below.
1. Text Fields
Text fields are used when you want the
user to type letters, numbers, etc. in
a form.
<form>
First name:
<input type="text" name="firstname">
<br>
Last name:
<input type="text" name="lastname">
</form>

Radio Buttons
Radio Buttons are used when you want the user to
select one of a limited number of choices.
<form>
<input type="radio" name="sex" value="male"> Male
<br>
<input type="radio" name="sex" value="female"> Female
</form>

Checkboxes
Checkboxes are used when you want the user to select one
or more options of a limited number of choices.
<form>
I have a bike:
<input type="checkbox" name="vehicle" value="Bike">
<br>
I have a car:
<input type="checkbox" name="vehicle" value="Car">
<br>
I have an airplane:
<input type="checkbox" name="vehicle" value="Airplane">
</form>
Example-20

The Form's Action Attribute and the Submit Button
<form name="input" action="html_form_action.asp"
method="get">
Username:
<input type="text" name="user">
<input type="submit" value="Submit">
</form>

<body>
<form >
<select name="cars">
<option value="800"> Maruthi 800</option>
<option value="Alto">Maruthi ALTO</option>
<option value="Wagonor">Maruthi Wagonor</option>
<option value="Swift">Maruthi Swift</option>
</select>
</form>
</body>
</html>
Example -22

PHP Form handling
The most important thing to notice when dealing with HTML forms and
PHP is that any form element in an HTML page will automatically be
available to your PHP scripts.
<html>
<body>
<form action="welcome.php" method="post">
Name: <input type="text" name="name" />
Age: <input type="text" name="age" />
<input type="submit" />
</form>
</body>
</html> <html>
<body>
Welcome <?php echo $_POST["name"]; ?>.<br />
You are <?php echo $_POST["age"]; ?> years old.
</body>
</html
Welcome.php

The $_GET Variable
The $_GET variable is an array of variable names and values sent by the
HTTP GET method.
The $_GET variable is used to collect values from a form with method="get".
Information sent from a form with the GET method is visible to everyone (it
will be displayed in the browser's address bar) and it has limits on the amount
of information to send (max. 100 characters).
The $_POST Variable
The $_POST variable is an array of variable names and values sent by
the HTTP POST method.
The $_POST variable is used to collect values from a form with
method="post". Information sent from a form with the POST method is
invisible to others and has no limits on the amount of information to send.

The $_REQUEST Variable
The PHP $_REQUEST variable contains the contents of both
$_GET, $_POST.
The PHP $_REQUEST variable can be used to get the result from
form data sent with both the GET and POST methods.
Welcome <?php echo $_REQUEST["name"]; ?>.<br />
You are <?php echo $_REQUEST["age"]; ?> years old!

Server Side Includes
You can insert the content of a file into a PHP file before the server
executes it, with the include() or require() function
The two functions are identical in every way, except how they
handle errors.
The include() function generates a warning (but the script will
continue execution) while the require() function generates a fatal
error (and the script execution will stop after the error).
These two functions are used to create functions, headers,
footers, or elements that can be reused on multiple pages

The include() Function
 The include() function takes all the text in a specified file and
copies it into the file that uses the include function.
<html>
<body>
<?php include("header.php"); ?>
<h1>Welcome to my home page</h1>
<p>Some text</p>
</body>
</html>
Example

<html>
<body>
<a href="default.php">Home</a> |
<a href="about.php">About Us</a> |
<a href="contact.php">Contact Us</a>
</body>
</html>
Menu.php
<?php include("menu.php"); ?>
<h1>Welcome to my home page</h1>
<p>Some text</p>
</body>
</html>

The require() Function
 The require() function is identical to include(), except that it
handles errors differently.
 The include() function generates a warning (but the script will
continue execution) while the require() function generates a fatal
error (and the script execution will stop after the error).


Opening a File
 The fopen() function is used to open files in PHP.
 The first parameter of this function contains the name of the file
to be opened and the second parameter specifies in which mode
the file should be opened:

Modes
r
r+
w
w+
a
a+
x
x+
Description
Read only. Starts at the beginning of the file
Read/Write. Starts at the beginning of the file
Write only. Opens and clears the contents of file; or creates a new file if it
doesn't exist
Read/Write. Opens and clears the contents of file; or creates a new file if it
doesn't exist
Append. Opens and writes to the end of the file or creates a new file if it doesn't
exist
Read/Append. Preserves file content by writing to the end of the file
Write only. Creates a new file. Returns FALSE and an error if file already exists
Read/Write. Creates a new file. Returns FALSE and an error if file already exists

<?php
$file = fopen("Cinderella .txt", "r") or exit("Unable to open file!");
//Output a line of the file until the end is reached
while(!feof($file))
{
echo fgets($file). "<br />";
}
fclose($file);
?>
Reading a File Line by Line
Example-43

Create an Upload-File Form
Example 40
<html>
<body>
<form action="upload_file.php" method="post"
enctype="multipart/form-data">
Filename:
<input type="file" name="file" id="file" />
<br />
<input type="submit" name="submit" value="Submit" />
</form>
</body>
</html>
To allow users to upload files from a form can be very useful.

 • The enctype attribute of the <form> tag specifies which
content-type to use when submitting the form. "multipart/form-
data" is used when a form requires binary data, like the contents
of a file, to be uploaded
 • The type="file" attribute of the <input> tag specifies that the
input should be processed as a file. For example, when viewed
in a browser, there will be a browse-button next to the input field

upload_file.php
<?php
if ($_FILES["file"]["error"] > 0)
{
echo "Error: " . $_FILES["file"]["error"] . "<br />";
}
else
{
echo "Upload: " . $_FILES["file"]["name"] . "<br />";
echo "Type: " . $_FILES["file"]["type"] . "<br />";
echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
echo "Stored in: " . $_FILES["file"]["tmp_name"];
}
?>

By using the global PHP $_FILES array you can upload files from a
client computer to the remote server.
The first parameter is the form's input name and the second index
can be either "name", "type", "size", "tmp_name" or "error". Like
this:
• $_FILES["file"]["name"] - the name of the uploaded file
• $_FILES["file"]["type"] - the type of the uploaded file
• $_FILES["file"]["size"] - the size in bytes of the uploaded file
• $_FILES["file"]["tmp_name"] - the name of the temporary copy of
the file stored on the server
• $_FILES["file"]["error"] - the error code resulting from the file
upload

Saving the Uploaded File
 move_uploaded_file
 This function checks to ensure that the file designated by
filename is a valid upload file (meaning that it was uploaded via
PHP's HTTP POST upload mechanism). If the file is valid, it will
be moved to the filename given by destination.

 filename The filename of the uploaded file.
 destination The destination of the moved file.
The temporary copied files disappears when the script
ends. To store the uploaded file we need to copy it to a
different location:
Example Program

What is a Cookie?
 A cookie is often used to identify a user. A cookie is a small file
that the server embeds on the user's computer. Each time the
same computer requests a page with a browser, it will send the
cookie too. With PHP, you can both create and retrieve cookie
values.

How to Create a Cookie?
The setcookie() function is used to set a cookie.
Note: The setcookie() function must appear BEFORE the <html>
tag.
Syntax
setcookie(name, value, expire, path, domain);
<?php
setcookie("user", “UC College ", time()+3600);
?>

How to Retrieve a Cookie Value?
 The PHP $_COOKIE variable is used to retrieve a cookie value.
 In the example below, we retrieve the value of the cookie named
"user" and display it on a page:
<?php
// Print a cookie
echo $_COOKIE["user"];
// A way to view all cookies
print_r($_COOKIE);
?>

isset() function
 In the following example we use the isset() function to find out if
a cookie has been set:
<html>
<body>
<?php
if (isset($_COOKIE["user"]))
echo "Welcome " . $_COOKIE["user"] . "!<br />";
else
echo "Welcome guest!<br />";
?>
</body>
</html>

 When creating scripts and web applications, error handling is an
important part. If your code lacks error checking code, your
program may look very unprofessional and you may be open to
security risks.
PHP Error Handling

Basic Error Handling: Using the die() function
<?php
$file=fopen("welcome.txt","r");
?>
If the file does not exist you might get an error :
This language construct is equivalent to exit().
<?php
if(!file_exists("welcome.txt"))
{
die("File not found");
}
else
{
$file=fopen("welcome.txt","r");
}
?>

PHP Filter?
 A PHP filter is used to validate and filter data coming from
insecure sources.
Why use a Filter?
Almost all web applications depend on external input. Usually
this comes from a user or another application (like a web
service). By using filters you can be sure your application gets
the correct input type.
What is external data?
• Input data from a form
• Cookies
• Web services data
• Server variables
• Database query results

Functions and Filters
 To filter a variable, use one of the following filter functions:
 • filter_var() - Filters a single variable with a specified filter
 • filter_var_array() - Filter several variables with the same or
different filters
 • filter_input - Get one input variable and filter it
 • filter_input_array - Get several input variables and filter
them with the same or different filters

validate an integer using the filter_var()
function
<?php
$int = 123;
if(!filter_var($int, FILTER_VALIDATE_INT))
{
echo("Integer is not valid");
}
else
{
echo("Integer is valid");
}
?>

<?php
$a = 'tiji@macfast.org';
if ( filter_var('$a', FILTER_VALIDATE_EMAIL))
{
echo "Email is valid";
}
else
{
echo "Email is not valid";
}
var_dump($a);
?>
Var_dump - This function displays structured information about one or
more expressions that includes its type and value.
Example - Validate an Email Id

Validating and Sanitizing
There are two kinds of filters:
Validating filters:
• Are used to validate user input
• Strict format rules (like URL or E-Mail validating)
• Returns the expected type on success or FALSE on failure
Sanitizing filters:
• Are used to allow or disallow specified characters in a string
• No data format rules
• Always return the string
<?php
$no = 12.5;
var_dump(filter_var($no, FILTER_SANITIZE_NUMBER_INT));
?>

Validate Input
filter_input() function is using for validate input
<form action="email.php" method="get">
Enter Email
<input name="email" type="text" />
<input type="submit" name="Submit" value="Submit">
</form>

<?php
if (!filter_input(INPUT_GET, "email", FILTER_VALIDATE_EMAIL))
{
echo "E-Mail is not valid";
}
else
{
echo "E-Mail is valid";
}
?>
Email.php

What is MySQL?
 MySQL is a database server
 MySQL is ideal for both small and large applications
 MySQL supports standard SQL
 MySQL compiles on a number of platforms
 MySQL is free to download and use
 PHP combined with MySQL are cross-platform (you can develop
in Windows and serve on a Unix platform)

Basic commands on mysql
1. CREATE DATABASE;
2. SHOW DATABASES;
3. USE database name;
4. CREATE TABLE
5. SHOW TABLES;
6. DESCRIBE table name;
7. DROP TABLE table name;
8. DROP DATABASE database name;
9. ALTER TABLE table name
11. SELECT
12 . DELETE FROM table name;
13 .TRUNCATE [TABLE] tbl_name

Connection to a MySQL Database
 Before you can access data in a database, you must create a
connection to the database.
 In PHP, this is done with the mysql_connect() function.
Syntax
mysql_connect(servername,username,password);
Parameter Description
servername Specifies the server to connect to. Default value is "localhost"
username Specifies the username to log in with. Default value is the
name of the user that owns the server process
password Specifies the password to log in with. Default is ""

Example- MySQL Connection
<?php
$con = mysql_connect("localhost","root","");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
// some code
mysql_close($con);
?>

Example – Create Database
<?php
if (!$con)
{
}
if (mysql_query("CREATE DATABASE pmg",$con))
{
echo "Database created";
}
else
{
echo "Error creating database: " . mysql_error();
}
mysql_close($con);
?>
mysql_query() sends an unique query to the currently active database on the
server

Example - macfastphpphps3example
mysql_select_db
 Select a MySQL database
 Sets the current active database on the server
 Every subsequent call to mysql_query() will be made on the
active database.

Insert Data Into a Database Table
<?php
if (!$con)
{
}
mysql_select_db(“pmg" ,$con);
mysql_query("INSERT INTO student (Rollno, Name, Mark)
VALUES (1, 'Raju', 35 )", $con);
mysql_close($con);
?>

Insert Data From a Form Into a Database
<html>
<body>
<form action="insert.php" method="post">
Roll No: <input type="text" name="rollNo" />
Name : <input type="text" name="name" />
Mark : <input type="text" name="mark" />
<input type="submit" />
</form>
</body>
</html>

<?php
if (!$con)
{
}
mysql_select_db(“pmg", $con);
$sql="INSERT INTO student (rollno, name, mark)
VALUES
('$_POST[rollno]','$_POST[name]','$_POST[mark]')";
if (!mysql_query($sql,$con))
{
die('Error: ' . mysql_error());
}
print_r($_POST);
echo "1 record added";
mysql_close($con)
?>
Insert.php

Select Data From a Database Table
<?php
if (!$con)
{
}
mysql_select_db("mca2007", $con);
$result = mysql_query("SELECT * FROM Student");
while($row = mysql_fetch_array($result))
{
echo $row['Rollno'] . " " . $row['Name']. " " . $row['Mark'];
echo "<br />";
}
mysql_close($con);
?>

Display the Result in an HTML Table
 Example Program
Where clause Example Program
Update Example Program
Delete

Php and MySQL

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