Web Application Development (1)

Build Bright University Faculty of Information and Technology

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Chapter 1: Introduction to PHP

Chapter 2: Data type and Variable

Chapter 3: Control Structure

Chapter 4: Loop Structure

Chapter 5: PHP Array Objects

Chapter 6: PHP Function

Chapter 7: PHP Forms

Chapter 8: PHP Date Function

Chapter 9: MySQL Database

Chapter10: PHP MySQL Database Connection

Chapter11: PHP cookies and sessions

Chapter12: PHP Include and Require

PHP and MySQL Web Application Development


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Contents

PHP









MySQL Chapter 9: MySQL Database

Chapter10: PHP MySQL Database Connection

Chapter11: PHP cookies and sessions

Chapter12: PHP Include and Require


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Table of Contents

PHP


Introduction to PHP .................................................................................6 How the Pieces of the AMP Module Work Together ..............................6 Apache .....................................................................................................7 PHP (Hypertext Preprocessor) .................................................................7 MySQL ....................................................................................................8


Overview of PHP Structure and Syntax...................................................9 How PHP Fits with HTML ......................................................................9 What is a PHP File? .................................................................................9 How to write php code .............................................................................9 PHP Comments ........................................................................................10 PHP Constants and Variables ..................................................................10 Overview of constants........................................................................10 Overview of variables ........................................................................11 The Concatenation Operator ....................................................................12 The PHP Operators ..................................................................................13 Arithmetic Operators .........................................................................13 Assignment Operators ........................................................................13 Comparison Operators .......................................................................14 Logical Operators...............................................................................14 Conditional Operator .........................................................................14


If Statement ..............................................................................................15 if.....else Statements ........................................................................15 if.....else if Statements .....................................................................16 switch Statements.....................................................................................17


Looping ................................................................................................19 The while Statement ................................................................................19 The do while statement ....................................................................22 The for statement .....................................................................................23 The foreach statement ..............................................................................25


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Introduction ..............................................................................................27 The while Statement ................................................................................27 Whats array? ...........................................................................................27 Numeric Array .........................................................................................27 Accessing Array Contents........................................................................30 Associative Arrays ...................................................................................30 Using Loops to Access the Array Contents .............................................32 The foreach loop ................................................................................32 each( ) construct .................................................................................33 list( ) construct ...................................................................................34 Multidimensional Arrays .........................................................................36 List of Array Functions ............................................................................37


PHP Function ...........................................................................................41 What is function? .....................................................................................41 Naming Your Function ............................................................................42 Using Parameters .....................................................................................43 Returning from Functions ........................................................................46 Returning Values from Functions ............................................................48


Overview ................................................................................................50 The GET method......................................................................................50 The POST method....................................................................................53 The $_REQUEST variable ......................................................................55 Using Array as form elements values ......................................................57


The PHP Date( ) Function........................................................................59 Date( ) - Format the Date .........................................................................60

MySQL

Chapter 9: MySQL Database

What is MySQL? .....................................................................................62 Text Types ...............................................................................................62 Number Types ..........................................................................................63 Date Types ...............................................................................................63 Column Modifiers ....................................................................................63 Working with SQL Command .................................................................64 Working with SQL statements .................................................................65


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Chapter 10: PHP MySQL Database Connection

How to connect to php with mysql database server? ...............................67 How to close connection ....................................................................67 How to select database .......................................................................68 How to manipulate data from php with mysql ...................................68

Chapter 11: PHP cookies and sessions

PHP Cookies ............................................................................................71 What is a Cookie? ..............................................................................71 How to Create a Cookie? ...................................................................71 How to Retrieve a Cookie Value? .....................................................72 How to Delete a Cookie? ...................................................................73 PHP Sessions ...........................................................................................73 PHP Session Variables .......................................................................73 Starting a PHP Session.......................................................................73 Storing a Session Variable .................................................................74 Destroying a Session ..........................................................................75

Chapter 12: PHP Include and Require

Server Side Includes (SSI) .......................................................................76 PHP include() Function............................................................................76 PHP require() Function ............................................................................77 Error Example require() Function ............................................................78 Error message...........................................................................................78


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Chapter 1:

Introduction to PHP

PHP is a powerful language and the interpreter, whether included in a web server as a module or executed as a separate CGI binary, is able to access files, execute commands and open network connections on the server. These properties make anything run on a web server insecure by default. PHP is designed specifically to be a more secure language for writing CGI programs than Perl or C, and with correct selection of compile-time and runtime configuration options, and proper coding practices, it can give you exactly the combination of freedom and security you need.

As there are many different ways of utilizing PHP, there are many configuration options controlling its behavior. A large selection of options guarantees you can use PHP for a lot of purposes, but it also means there are combinations of these options and server configurations that result in an insecure setup.

The configuration flexibility of PHP is equally rivaled by the code flexibility. PHP can be used to build complete server applications, with all the power of a shell user, or it can be used for simple server-side includes with little risk in a tightly controlled environment. How you build that environment, and how secure it is, is largely up to the PHP developer.

How the Pieces of the AMP Module Work Together

Now that we have covered some of the history of open source, its important to understand the role each of these programs (Apache, MySQL, and PHP) plays in creating your Web site.

Imagine that your dynamic Web site is a fancy restaurant. Diners come to your place, and each one wants something different and specific. They dont worry so much about how the food is prepared, as long as it looks and tastes delicious. Unlike a buffet-type spread, where everything is laid out and your patrons simply choose from whats available (the analogy being a more static, informational Web site with little interaction and input from your visitors), a nice restaurant encourages patron/waiter interaction and complete customization for any specific dietary needs (a dynamic Web site where the visitor can choose what he or she wants to see).

In this scenario, we can attribute the three components of the AMP module as follows:

Apache: This is your highly trained master of culinary arts, the chef. Whatever people ask for, she prepares it without complaint. She is quick, flexible, and able to prepare a multitude of different types of foods. Apache acts in much the same way as your HTTP server, parsing files and passing on the results.

PHP: This is the waiter. He gets requests from the patron and carries them back to the kitchen with specific instructions about how the meal should be prepared.

MySQL: This is your stockroom of ingredients (or in this case, information).

Introduction to PHP


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When a patron (or Web site visitor) comes to your restaurant, he or she sits down and orders a meal with specific requirements, such as a steak, well done. The waiter (PHP) takes those specific requirements back to the kitchen and passes them off to the chef (Apache). The chef then goes to the stockroom (MySQL) to retrieve the ingredients (or data) to prepare the meal and presents the final dish to the patron, exactly the way he or she ordered the meal.

Apache

Apache acts as your Web server. Its main job is to parse any file requested by a browser and display the correct results according to the code within that file. Apache is quite powerful and can accomplish virtually any task that you, as a Webmaster, require.

The version of Apache covered in this book is the most recent and stable at the time of this writing: version 2.0.47. The features and server capabilities available in this version include the following:

Password-protected pages for a multitude of users Customized error pages Display of code in numerous levels of HTML, and the capability to determine at what

level the browser can accept the content Usage and error logs in multiple and customizable formats Virtual hosting for different IP addresses mapped to the same server Directory Index directives to multiple files URL aliasing or rewriting with no fixed limit

According to the Netcraft Web site (www.netcraft.com), at the time of this writing Apache is running over 27 million Internet servers, more than Microsoft, Sun ONE, and Zeus combined. Its flexibility, power, and, of course, price make it a popular choice. It can be used to host a Web site to the general public, or a company-wide intranet, or for simply testing your pages before they are uploaded to a secure server on another machine. Later in this chapter, we discuss how to configure your Apache setup to accommodate all of these options.

PHP (Hypertext Preprocessor)

PHP is a server-side scripting language that allows your Web site to be truly dynamic. PHP stands for PHP: Hypertext Preprocessor (and, yes, were aware PHP is a recursive cronym probably meant to confuse the masses). Its flexibility and relatively small learning curve (especially for programmers who have a background in C, Java, or Perl) make it one of the most popular scripting languages around. PHPs popularity continues to increase as businesses and individuals everywhere embrace it as an alternative to Microsofts ASP language and realize that PHPs benefits most certainly outweigh the costs (three cheers for open source!).

According to Zend Technologies, Ltd., the central source of PHP improvements and designers of the Zend Engine, which supports PHP applications, PHP code can now be found in approximately 9 million Web sites.


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The version of PHP referenced in this book is the most recent stable release at the time of publication: version 4.3.3. Although we discuss several of the most common uses and functions of PHP, you can find a complete list of PHP functions in Appendix B of this book. As you continue to program in PHP and your comfort level increases (or the demands of your boss grow), we encourage you to expand your use of built-in PHP functions to take advantage of its tremendous power. You can download the PHP software from PHPs Web site at www.php.net.

MySQL

Another open source favorite, MySQL is the database construct that enables PHP and Apache to work together to access and display data in a readable format to a browser. It is a Structured Query Language server designed for heavy loads and processing of complex queries. As a relational database system, MySQL allows many different tables to be joined together for maximum efficiency and speed.

This book references version 4.0.15a, the most stable release of MySQL at the time of publication. While a complete list of features can be found at the MySQLWeb site (www.mysql.com), some of the more popular features of this program are as follows:

Multiple CPUs usable through kernel threads. Multi-platform operation. Numerous column types cover virtually every type of data. Group functions for mathematical calculations and sorting. Commands that allow information about the databases to be easily and succinctly

shown to the administrator. Function names that do not affect table or column names. A password and user verification system for added security. Up to 32 indexes per table permitted; this feature has been successfully implemented at

levels of 60,000 tables and 5,000,000,000 rows. International error reporting usable in many different countries.

MySQL is the perfect choice for providing data via the Internet because of its ability to handle heavy loads and its advanced security measures.


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Chapter 2:

Overview of PHP Structure and Syntax

PHP programs are written using a text editor, such as Notepad or WordPad, just like HTML pages. However, PHP pages, for the most part, end in a .php extension. This extension signifies to the server that it needs to parse the PHP code before sending the resulting HTML code to the viewers Web browser.

How PHP Fits with HTML

We assume that you know some HTML before you embark on your PHP/Apache/MySQL journey, and youve undoubtedly seen how JavaScript code and other languages can be interspersed within the HTML code in an HTML page. What makes PHP so different is that it not only allows HTML pages to be created on the fly; it is invisible to your Web site visitors. The only thing they see when they view the source of your code is the resulting HTML output. This gives you more security for your PHP code and more flexibility in writing it.

HTML can also be written inside the PHP section of your page; this allows you to format text while keeping blocks of code together. This will also help you write organized, efficient code, and the browser (and, more important, the viewer) wont know the difference.

PHP can also be written as a standalone program, with no HTML at all. This is helpful for storing your connection variables, redirecting your visitors to another page of your site, or performing other functions that we discuss in this book.

What is a PHP File?

PHP files can contain text, HTML tags and scripts PHP files are returned to the browser as plain HTML PHP files have a file extension of ".php", ".php3", or ".phtml"

How to write php code

One of the benefits of using PHP is that it is relatively simple and straightforward. As with any computer language, there is usually more than one way to perform the same function. Once you feel comfortable writing some PHP programs, you can research shortcuts to make yourself and your code more efficient. For the sake of simplicity, we cover only the most common uses, rules, and functions of PHP.

Data type and Variable


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You should always keep in mind these two basic rules of PHP:

PHP is denoted in the page with opening and closing tags as follows:

PHP lines end with a semicolon, generally speaking:

PHP Comments

Comments can be added to explain the JavaScript, or to make it more readable. Single line comments start with //. Multi line comments start with /* and end with */.

PHP Constants and Variables

Overview of constants

A constant is a placeholder for a value that you reference within your code. Constants are typically named with capital letters (so you can easily find them within your code), and the values are usually formally defined before using them. Constant names must begin with a letter or underscore and cannot begin with a number. Names are also case-sensitive.

The values assigned to constants are defined with the PHP function define(). Once theyve been defined, they cant be changed or undefined.

Syntax:

Or

define(ConstantsName,Constans value);


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Ex: first_prog.php

Result:

Overview of variables

Unlike constants, variables are obviously meant to be variablethey are meant to change or be changed at some point in your program. Variables also do not need to be defined or declared and can simply be assigned when needed.

Variables are denoted with a dollar sign ($) and are not case-sensitive as are constants.

Syntax:

Note: 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 variable name should not contain spaces. If a variable name is more than one word, it should be separated with underscore ($my_string), or with capitalization ($MyString)

Build Bright University

$variable_name=value;


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Ex: first_prog.php

Result:

The Concatenation Operator

There is only one string operator in PHP. The concatenation operator (.) is used to put two string values together.

Ex:

Build Bright University


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The PHP Operators

Operators are symbols that you can use to manipulate values and variables by performing an operation on them.

Arithmetic Operators

Arithmetic operators are straightforward; they are just the normal mathematical operators. PHPs arithmetic operators are shown in table below:

Operator Description Example Result

+ Addition x=2

x+2 4

-

Subtraction x=2 5-x

3

* Multiplication x=4

x*5 20

/ Division 15/5 5/2 3 2.5

% Modulus (division remainder) 5%2

10%8 10%2

1 2 0

++ Increment x=5

x++ x=6

--

Decrement x=5 x--

x=4

Assignment Operators

Youve already seen the basic assignment operator (=). Always refer to this as the assignment operator and read it as is set to.

Combination Assignment Operators

In addition to the simple assignment, there is a set of combined assignment operators. Each of them is a shorthand way of performing another operation on a variable and assigning the result back to that variable.

Operator Example Is The Same As = x=y x=y

+= x+=y x=x+y -= x-=y x=x-y *= x*=y x=x*y /= x/=y x=x/y .= x.=y x=x.y

%= x%=y x=x%y


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Comparison Operators

The comparison operators compare two values. Expressions using these operators return either of the logical values true or false depending on the result of the comparison.

Given that x=5, the table below explains the comparison operators:

Operator Description Example = = is equal to x= =8 is false

= = = is exactly equal to (value and type) x= = =5 is true x= = ="5" is false

!= is not equal x!=8 is true > is greater than x>8 is false < is less than x= is greater than or equal to x>=8 is false


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Chapter 3:

If you want to sensibly respond to your users input, your code needs to be able to make decisions. The constructs that tell your program to make decisions are called conditionals.

If Statement

You can use an if statement to make a decision. You should give the if statement a condition to use. If the condition is true, the following block of code will be executed. Conditions in if statements must be surrounded by parentheses ( ).

Syntax:

Ex: if_statement.php

if.....else Statements

You may often need to decide not only whether you want an action performed, but also which of a set of possible actions you want performed.

An else statement allows you to define an alternative action to be taken when the condition in an if statement is false. Say you want to warn Bobs customers when they do not order anything. On the other hand, if they do make an order, instead of a warning, you want to show them what they ordered.

Syntax:

Control Structure

if (condition){ Block statement;

}

Test php

if (condition){ Statement to be execute if condition is true} else{

Statement to be execute if condition is not true}


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Ex: if_else.php

if.....else if Statements

For many of the decisions you make, you have more than two options. You can create a sequence of many options using the else if statement, which is a combination of an else and an if statement. When you provide a sequence of conditions, the program can check each until it finds one that is true.

Syntax:

Ex: if_elseif.php

if (condition){block statement1;} elseif (condition1) {block statement 2;} elseif (condition2) {block statement 3;}

else{block n;}


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switch Statements

The switch statement works in a similar way to the if statement, but it allows the condition to take more than two values. In an if statement, the condition can be either true or false. In a switch statement, the condition can take any number of different values, as long as it evaluates to a simple type (integer, string, or float).You need to provide a case statement to handle each value you want to react to and, optionally, a default case to handle any that you do not provide a specific case statement for.

Syntax:

Ex:switch.php

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; }


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switch.php (continues)

case 6: echo "Number $x = Satureday"; break; default: echo "Number $x = Sunday"; } ?>


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Chapter 4:

Looping statements in PHP are used to execute the same block of code a specified number of times.

Looping

Very often when you write code, you want the same block of code to run a number of times. You can use looping statements in your code to perform this.

In PHP we have the following looping statements:

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

The simplest kind of loop in PHP is the while loop. Like an if statement, it relies on a condition. The difference between a while loop and an if statement is that an if statement executes the following block of code once if the condition is true. A while loop executes the block repeatedly for as long as the condition is true.

You generally use a while loop when you dont know how many iterations will be required to make the condition true. If you require a fixed number of iterations, consider using a for loop.

Syntax:

Loop Structure

while (condition){ code to be executed;

}


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Ex: while_loop.php

Result:

A while Statement


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Create table with while loop: create_table_while.php

Result:

Distance Cost


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The do while statement

A do..while loop differs from a while loop because the condition is tested at the end. This means that in a do..while loop, the statement or block within the loop is always executed at least once.

Even if you consider this example in which the condition will be false at the start and can never become true, the loop will be executed once before checking the condition and ending

Syntax:

Ex1: do_while.php

Ex2:even_odd.php

do { code to be executed; } while (condition);

A while Statement


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Result:

The for statement

The for statement is the most advanced of the loops in PHP.

In it's simplest form, the for statement is used when you know how many times you want to execute a statement or a list of statements.

Syntax:

Ex:for.php

for(init; cond; incr){ code to be execute; }

A while Statement


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Result:

Ex2: table_bgcolor.php

The for loop statement

Alternating row colors


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Result:

The foreach statement

The foreach statement is used to loop through arrays.

Syntax:

For every loop, the value of the current array element is assigned to $value (and the array pointer is moved by one) - so on the next loop, you'll be looking at the next element.

Ex:foreach.php

foreach ($array as $value) { code to be executed; }


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Ex2:foreach_table.php

Result:

Read array value into table


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Chapter 5:

Introduction

Weve talked about variables and how they are used, but what if we had more than one value assigned to that variable? That, my friends, is a good old-fashioned array. Arrays are nothing more than lists of bits of information mapped with keys and stored under one variable name. For example, you can store a persons name and address or a list of states in one variable.

Whats array?

An array is a data structure that stores one or more similar type of values in a single value. There are three different kinds of arrays and each array value is accessed using an ID which is called array index.

Numeric array - An array with a numeric index. Values are stored and accessed in linear fashion Associative array - An array with strings as index. This stores element values in association with key values rather than in a strict linear index order. Multidimensional array - An array containing one or more arrays and values are accessed using multiple indices.

Numeric Array

These arrays can store numbers, strings and any object but their index will be pre-presented by numbers. By default array index starts from zero.

Syntax:

Set string value into array: Ex: $name=array(Sok ,Chan, Nara, Nary, Ratha); or $name[0]=Sok; $name[1]=Chan; $name[2]=Nara; $name[3]=Nary; $name[4]=Ratha; Set string value into array: Ex: $score=array(10,20,30,40,50);

PHP Array Objects

$names[key] = value; or $names = array("value0","value1","value2");


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Ex: num_array.php (first method to create array)

Result:

The Array Objects Using Numerically array


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Ex: num_array1.php (second method to create array)

Result:

The Array Objects

Using Numerically array


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Accessing Array Contents

To access the contents of a variable, you use its name. If the variable is an array, you access the contents using the variable name and an index. The index indicates which of the values in the array you access. The index is placed in square brackets after the name.

Ex: $numbers = array("one","two","three","four","five");

echo $numbers[2];// three

Using Loops to Access the Array Contents

Because the array is indexed by a sequence of numbers, you can use a for loop to more easily display its contents:

Ex:

Associative Arrays

The associative arrays are very similar to numeric arrays in term of functionality but they are different in terms of their index. Associative array will have their index as string so that you can establish a strong association between key and values.

Syntax:

Set string value into array: Ex: $name[firstname] = Sok; $name[lastname] = San; or $name = array(firstname=>Sok, lastname=>San);

Note: If you wanted to simply store a list and not worry about the particular order, or what each value should be mapped to (such as a list of states or flavors of shaved ice), you dont need to explicitly name the keys and PHP will assign invisible internal keys for processing. This would be set up as follows:

$array_name=("key0"=>"value0","key1"=>"value1",); or $array_name["key"]= "value";

$numbers = array("one","two","three","four","five");

for($i=0;$i


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Ex:asso_array.php

Associate Array

First method


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Result:

Using Loops to Access the Array Contents

Because the indices in an array are not numbers, you cannot use a simple counter in a for loop to work with the array. However, you can use the foreach loop or the list( ) and each( ) constructs.

The foreach loop

The foreach loop has a slightly different structure when using associative arrays. You can use it exactly as you did in the previous example, or you can incorporate the keys as well:

Ex: foreach_ass.php Using foreach to access associative array contents


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Result:

each( ) construct

The following code lists the contents of the $prices array using the each() construct:

Ex: each_ass.php

Using each() construct Using each() construct to access associative


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Result:

list( ) construct

There is a more elegant and more common way of doing the same thing. The construct list( ) can be used to split an array into a number of values. You can separate two of the values that the each( ) function gives you like this:

$salaries = array("sophal" => "500 $","sreyleak" => "300 $", "narry" => "100 $");

list( $employee, $value ) = each( $salaries);

This line uses each() to take the current element from $prices, return it as an array, and make the next element current. It also uses list() to turn the 0 and 1 elements from the array returned by each() into two new variables called $employee and $value. You can loop through the entire $value array, echoing the contents using this short script:

$salaries = array("sophal" => "500 $","sreyleak" => "300 $", "narry" => "100 $");

while( list( $employee, $value )= each($salaries)) { echo $employee - $value ;

}


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Ex:list_ass.php

Result:

Using list() construct Using list() construct to access associative


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Multidimensional Arrays

A multi-dimensional 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. Values in the multi-dimensional array are accessed using multiple index.

Ex:mul_array.php

Multidimensional Array Using Multidimensional Array


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Result:

List of Array Functions

PHP: indicates the earliest version of PHP that supports the function. Function Description

array( ) Create an array array_change_key_case( ) Returns an array with all keys in lowercase or uppercase array_chunk( ) Splits an array into chunks of arrays array_combine( ) Creates an array by using one array for keys and another for its

values

array_count_values( )

Returns an array with the number of occurrences for each value

array_diff( ) Compares array values, and returns the differences array_diff_assoc( ) Compares array keys and values, and returns the differences array_diff_key( ) Compares array keys, and returns the differences array_diff_uassoc( ) Compares array keys and values, with an additional user-made

function check, and returns the differences

array_diff_ukey( ) Compares array keys, with an additional user-made function check, and returns the differences

array_fill( ) Fills an array with values array_fill_keys( ) Fill an array with values, specifying keys array_filter( ) Filters elements of an array using a user-made function array_flip( ) Exchanges all keys with their associated values in an array


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array_intersect( ) Compares array values, and returns the matches array_intersect_assoc( ) Compares array keys and values, and returns the matches array_intersect_key( ) Compares array keys, and returns the matches array_intersect_uassoc( ) Compares array keys and values, with an additional user-made

function check, and returns the matches

array_intersect_ukey( ) Compares array keys, with an additional user-made function check, and returns the matches

array_key_exists( ) Checks if the specified key exists in the array array_keys( ) Returns all the keys of an array array_map( ) Sends each value of an array to a user-made function, which

returns new values

array_merge( ) Merges one or more arrays into one array array_merge_recursive( ) Merges one or more arrays into one array array_multisort( ) Sorts multiple or multi-dimensional arrays array_pad( ) Inserts a specified number of items, with a specified value, to an

array

array_pop( ) Deletes the last element of an array array_product( ) Calculates the product of the values in an array array_push( ) Inserts one or more elements to the end of an array array_rand( ) Returns one or more random keys from an array array_reduce( ) Returns an array as a string, using a user-defined function array_reverse( ) Returns an array in the reverse order array_search( ) Searches an array for a given value and returns the key array_shift( ) Removes the first element from an array, and returns the value of

the removed element

array_slice( ) Returns selected parts of an array array_splice( ) Removes and replaces specified elements of an array array_sum( ) Returns the sum of the values in an array array_udiff( ) Compares array values in a user-made function and returns an

array

array_udiff_assoc( ) Compares array keys, and compares array values in a user-made function, and returns an array

array_udiff_uassoc( ) Compares array keys and array values in user-made functions, and returns an array


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array_uintersect( ) Compares array values in a user-made function and returns an array

array_uintersect_assoc( ) Compares array keys, and compares array values in a user-made function, and returns an array

array_uintersect_uassoc( ) Compares array keys and array values in user-made functions, and returns an array

array_unique( ) Removes duplicate values from an array array_unshift( ) Adds one or more elements to the beginning of an array array_values( ) Returns all the values of an array array_walk( ) Applies a user function to every member of an array array_walk_recursive( ) Applies a user function recursively to every member of an array arsort( ) Sorts an array in reverse order and maintain index association asort( ) Sorts an array and maintain index association compact( ) Create array containing variables and their values count( ) Counts elements in an array, or properties in an object current( ) Returns the current element in an array each( ) Returns the current key and value pair from an array end( ) Sets the internal pointer of an array to its last element extract( ) Imports variables into the current symbol table from an array in_array( ) Checks if a specified value exists in an array key( ) Fetches a key from an array krsort( ) Sorts an array by key in reverse order ksort( ) Sorts an array by key list( ) Assigns variables as if they were an array natcasesort( ) Sorts an array using a case insensitive "natural order" algorithm natsort( ) Sorts an array using a "natural order" algorithm next( ) Advance the internal array pointer of an array pos( ) Alias of current() prev( ) Rewinds the internal array pointer range( ) Creates an array containing a range of elements reset( ) Sets the internal pointer of an array to its first element rsort( ) Sorts an array in reverse order


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shuffle( ) Shuffles an array sizeof( ) Alias of count( ) sort( ) Sorts an array uasort( ) Sorts an array with a user-defined function and maintain index

association

uksort( ) Sorts an array by keys using a user-defined function usort( ) Sorts an array by values using a user-defined function


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Chapter 6:

PHP Function

PHP functions are similar to other programming languages. A function is a piece of code which takes one more input in the form of parameter and does some processing and returns a value.

Functions exist in most programming languages; they separate code that performs a single, well-defined task. This makes the code easier to read and allows you to reuse the code each time you need to perform the same task.

What is function?

A function is a block of code that can be executed whenever we need it.

Creating PHP functions:

All functions start with the word "function()" Name the function - It should be possible to understand what the function does by its name. 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

Syntax:

Note: There are two parts which should be clear to you:

Creating a PHP Function Calling a PHP Function

PHP Function

function function_name($Argument1,$Argument2) { block statements; }


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Ex: show_msg.php

Naming Your Function:

The most important point to consider when naming your functions is that the name should be short but descriptive.

A few restrictions follow:

Your function cannot have the same name as an existing function. Your function name can contain only letters, digits, and underscores. Your function name cannot begin with a digit.

Many languages do allow you to reuse function names. his feature is called function overloading. However, PHP does not support function overloading, so your function cannot have the same name as any built-in function or an existing user-defined function. Note that although every PHP script knows about all the built-in functions, user-defined functions exist only in scripts where they are declared. his means that you could reuse a function name in a different file, but this would lead to confusion and should be avoided.

The following function names are legal:

name() name2() name_three() _namefour()

These names are illegal: 5name() name-six() fopen()

.::Hypertext Proprocessor Function.


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Note that although $name is not a valid name for a function, a function call like

$name( );

May well execute, depending on the value of $name. The reason is that PHP takes the value stored in $name, looks for a function with that name, and tries to call it for you. This type of function is referred to as a variable function and may occasionally be useful to you.

Using Parameters

To do their work, most functions require one or more parameters. A parameter allows you to pass data into a function. Here is a sample function that requires a parameter; it takes a one-dimensional array and displays it as a table:

Ex: getdata_into_table.php

If you call the create_table( ) function

function create_table($data) { echo ""; reset($data); //Remember this is used to point to the beginning $value = current($data); while ($value) { echo "$value\n"; $value = next($data); } echo ""; }

$my_array = array('Line one.','Line two.','Line three.'); create_table($my_array);


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Summary code:

Result:

Function with Parameter


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Ex: sum_func.php

Result:

.:: Function with parameter Function with Parameter


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Returning from Functions

The keyword return stops the execution of a function. When a function ends because either all statements have been executed or the keyword return is used, execution return is to the statement after the function call.

Ex:test_return.php

Result:

Returning from function


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Obviously, this is not a very useful way to use return. Normally, you want to return from the middle of a function only in response to a condition being met.

An error condition is a common reason to use a return statement to stop execution of a function before the end. If, for instance, you write a function to find out which of two numbers is greater, you might want to exit if any of the numbers are missing:

Ex2: larger.php

Returning from function


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Result:

Returning Values from Functions

Exiting from a function is not the only reason to use return. Many functions use return statements to communicate with the code that called them. Instead of echoing the result of the comparison in the larger() function, the function might have been more useful if it returned the answer. This way, the code that called the function can choose if and how to display or use it. The equivalent built-in function max() behaves in this way.

Ex: You can write the larger() function as follows: (larger1.php)

Returning value from function


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Result:

Ex3: resturn_sum_func.php

Result:

Returning value from function


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Chapter 7:

Overview

Using forms in a web based application is very common. Most forms are used to gather information like in a signup form, survey / polling, guestbook, etc.

A form can have the method set as post or get. When using a form with method = "post" you can use $_POST to access the form values. And when the form is using method = "get" you can use $_GET to access the values. The $_REQUEST super global can be used to access form values with method="post" and method="get" but it is recommended to use $_POST or $_GET instead so you will know from what method did the values come from.

The GET method

The GET method sends the encoded user information appended to the page request. The page and the encoded information are separated by the ? character.

The GET method produces a long string that appears in your server logs, in the browser's Location: box. The GET method is restricted to send upto 1024 characters only. Never use GET method if you have password or other sensitive information to be sent to the server. GET can't be used to send binary data, like images or word documents, to the server. The data sent by GET method can be accessed using QUERY_STRING environment variable. The PHP provides $_GET associative array to access all the sent information using GET method.

PHP Forms

http://www.test.com/index.htm?name1=value1&name2=value2


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Ex: post_method.php

Using Method Get


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Result:

After submit:

There are a few disadvantages to passing variables through a URL:

Everyone can see the values of the variables, so passing sensitive information isnt really very secure using this method.

The user can change the variable value in the URL, leaving your site potentially open to showing something youd rather not show.

A user might also pull up inaccurate or old information using a saved URL with older variables embedded in it.


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The POST method

The POST method transfers information via HTTP headers. The information is encoded as described in case of GET method and put into a header called QUERY_STRING.

The POST method does not have any restriction on data size to be sent. The POST method can be used to send ASCII as well as binary data. The data sent by POST method goes through HTTP header so security depends on HTTP protocol. By using Secure HTTP you can make sure that your information is secure. The PHP provides $_POST associative array to access all the sent information using GET method.

Ex:post_method.php

Using Method Get


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Result:

After submit:


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The $_REQUEST variable

The PHP $_REQUEST variable contains the contents of both $_GET, $_POST, and $_COOKIE. We will discuss $_COOKIE variable when we will explain about cookies.

The PHP $_REQUEST variable can be used to get the result from form data sent with both the GET and POST methods.

Ex: request_variable.php

Using Method Get


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Result:

After submit:


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Using Array as form elements values

You can get value from form elements by using array to store the values.

Ex: array_with_form.php

Using Array as Form Value. Select the programming languages you can use C++ Java PHP ASP Delphi


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Result:

After submit:


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Chapter 8:

The PHP date() function is used to format a time and/or date.

The PHP Date( ) Function

The PHP date() function formats a timestamp to a more readable date and time.

A timestamp is a sequence of characters, denoting the date and/or time at which a certain event occurred.

Syntax:

Parameter Description format Required. Specifies the format of the timestamp timestamp Optional. Specifies a timestamp. Default is the current date and time

Ex: date.php

Result:

PHP Date Function

date(format,timestamp);

Using Data Function


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Date( ) - Format the Date

The required format parameter in the date() function specifies how to format the date/time.

The following characters are recognized in the format parameter string:

format character Description

Example returned values

Day --- --- d Day of the month, 2 digits with leading zeros 01 to 31 D A textual representation of a day, three letters Mon through Sun j Day of the month without leading zeros 1 to 31 l (lowercase) A full textual representation of the day of the week Sunday through Saturday

N ISO-8601 numeric representation of the day of the week (added in PHP 5.1.0) 1 (for Monday) through 7 (for Sunday)

S English ordinal suffix for the day of the month, 2 characters st, nd, rd or th. Works well with j

w Numeric representation of the day of the week 0 (for Sunday) through 6 (for Saturday)

z The day of the year (starting from 0) 0 through 365 Week --- ---

W ISO-8601 week number of year, weeks starting on Monday (added in PHP 4.1.0) Example: 42 (the 42nd week in the year)

Month --- ---

F A full textual representation of a month, such as January or March January through December

m Numeric representation of a month, with leading zeros 01 through 12 M A short textual representation of a month, three letters Jan through Dec n Numeric representation of a month, without leading zeros 1 through 12 t Number of days in the given month 28 through 31

Year --- ---

L Whether it's a leap year 1 if it is a leap year, 0 otherwise.

o

ISO-8601 year number. This has the same value as Y, except that if the ISO week number (W) belongs to the previous or next year, that year is used instead. (added in PHP 5.1.0)

Examples: 1999 or 2003

Y A full numeric representation of a year, 4 digits Examples: 1999 or 2003

y A two digit representation of a year Examples: 99 or 03 Time --- ---


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a Lowercase Ante meridiem and Post meridiem am or pm A Uppercase Ante meridiem and Post meridiem AM or PM B Swatch Internet time 000 through 999 g 12-hour format of an hour without leading zeros 1 through 12 G 24-hour format of an hour without leading zeros 0 through 23 h 12-hour format of an hour with leading zeros 01 through 12 H 24-hour format of an hour with leading zeros 00 through 23 i Minutes with leading zeros 00 to 59 s Seconds, with leading zeros 00 through 59


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Chapter 9:

1. What is MySQL?

MySQL is an open source Relational Database Management System (RDBMS) based around the Structured Query Language (SQL). In short, MySQL is software that allows you to manage your databases.

The data in MySQL is stored in database objects called tables. A table is a collection of related data entries and it consists of columns and rows.

Database File: This is your main file that encompasses the entire Database and that is saved to your hard-drive or floppy disk.

Table: A table is a collection of data about a specific topic. There can be multiple tables in a database.

Field: Fields are the different categories within a Table. Tables usually contain multiple fields.

Datatypes: Datatypes are the properties of each field. A field only has 1 datatype.

There are three main types: text, numbers, and Dates/Times.

TEXT TYPES

CHAR( ) A fixed section from 0 to 255 characters long. VARCHAR( ) A variable section from 0 to 255 characters long. TINYTEXT A string with a maximum length of 255 characters. TEXT A string with a maximum length of 65535 characters. BLOB A string with a maximum length of 65535 characters. MEDIUMTEXT A string with a maximum length of 16777215 characters. MEDIUMBLOB A string with a maximum length of 16777215 characters. LONGTEXT A string with a maximum length of 4294967295 characters. LONGBLOB A string with a maximum length of 4294967295 characters.

The ( ) brackets allow you to enter a maximum number of characters will be used in the Column.

CHAR and VARCHAR are the most widely used types. CHAR is a fixed length string and is mainly used when the data is not going to vary much in it's length. VARCHAR is a variable length string and is mainly used when the data may vary in length.

CHAR may be faster for the database to process considering the fields stay the same length down the column. VARCHAR may be a bit slower as it calculates each field down the column, but it saves on memory space. Which one to ultimately use is up to you.

Using both a CHAR and VARCHAR option in the same table, MySQL will automatically change the CHAR into VARCHAR for compatibility reasons.

MySQL Database

Database File

Tables

Field

Data type

Value


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BLOB stands for Binary Large Object. Both TEXT and BLOB are variable length types that store large amounts of data. They are similar to a larger version of VARCHAR. These types can store a large piece of data information, but they are also processed much slower.

NUMBER TYPES

TINYINT( ) -128 to 127 normal 0 to 255 UNSIGNED.

SMALLINT( ) -32768 to 32767 normal 0 to 65535 UNSIGNED.

MEDIUMINT( ) -8388608 to 8388607 normal 0 to 16777215 UNSIGNED.

INT( ) -2147483648 to 2147483647 normal 0 to 4294967295 UNSIGNED.

BIGINT( ) -9223372036854775808 to 9223372036854775807 normal 0 to 18446744073709551615 UNSIGNED.

FLOAT A small number with a floating decimal point. DOUBLE( , ) A large number with a floating decimal point. DECIMAL( , ) A DOUBLE stored as a string , allowing for a fixed decimal point.

The integer types have an extra option called UNSIGNED. Normally, the integer goes from an negative to positive value. Using an UNSIGNED command will move that range up so it starts at zero instead of a negative number.

DATE TYPES

DATE YYYY-MM-DD. DATETIME YYYY-MM-DD HH:MM:SS. TIMESTAMP YYYYMMDDHHMMSS. TIME HH:MM:SS.

2. Column Modifiers A column modifier is an extra add on command to help the database organize and work better.

As mentioned on the previous page, the integer types have an extra option called UNSIGNED. Normally, the integer goes from an negative to positive value. Using an UNSIGNED command will move that range up so it starts at zero instead of a negative number.

Modifier commands are: INDEX, UNIQUE, PRIMARY KEY, AUTO_INCREMENT, NULL, NOT NULL, DEFAULT, BINARY, and ZEROFILL.

Indexing: is a way to improve a database performance. You are telling the database that THIS

specific column is special and may help organize the data. If there is a column you will be referring to often, it would probably be the best to be an INDEX column.

An INDEX column may have more than one cell holding the same data value. The two other index types are UNIQUE and PRIMARY KEY. UNIQUE states that each cell in the column should have a unique value. PRIMARY KEY is a special variety of the UNIQUE command.


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The AUTO_INCREMENT modifier works on any of the integer types. Each time a new row is added into the database table, the number in this column will appear and automatically increase by one from the previous row.

NULL: is no value. It is not space, it is not zero. A majority of the time you will want to specify

a field to be NOT NULL so that any blank entries will be considered as "something".

DEFAULT: will assign a default value to a cell if nothing is entered for the value. It will work on most data types except BLOB and TEXT.

BINARY: is used with CHAR and VARCHAR types. It causes the values to be treated as "binary strings" making them Case Sensitive.

ZEROFILL: is used with numeric data types. It will display leading zeros of a number based on the display width.

3. Working with SQL Command

3.1 How to create database on MYSQL server

Ex: create database managestudent; 3.2 How to show database

3.3 How to change database

3.4 How to delete database

Ex: DROP tblstudents; 3.4 How to create table

Ex: CREATE TABLE students( id int( 6 ) NOT NULL auto_increment, name text, sex char( 6 ) , dob date, );

CREATE DATABASE [database-name];

SHOW DATABASES;

USE [database-name];

DROP database-name;

CREATE TABLE table-name (field1 datatype, field2 datatype,);


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3.5 How to delete table

Ex: DROP TABLE tblstudent; 3.6 How to rename table

3.7 How to show table on database

3.8 How to view table structure

Ex: EXPLAIN tblstudents; 3.9 How to modify table structure

a) Add new field

Ex: ALTER TABLE tblscore ADD COLUMN maxscore int(2); b) Delete column of table

c) Change column name

d) Modify column on table

4. Working with SQL statements a) Insert statement

ex: INSERT INTO tblstudents(id,name,sex,dob) VALUES(001,dara,male,1984-12-20); INSERT INTO tblstudents(id,name,sex,dob)

VALUES(002,vantha,male,1984-12-20), (003,raksa,female, 1984- 12-20);

DROP TABLE [table-name];

EXPLAIN [table-name]; or DESCRIBE [table-name];

ALTER TABLE [table-name] ADD COLUMN [new-field-name] datatype;

ALTER TABLE [table-name] DROP [field-name];

RENAME TABLE [old-table-name] TO [new-table-name]; or ALTER TABLE [old-table-name] RENAME TO [new-table-name];

ALTER TABLE [table-name] CHANGE [old-column] [new-column] datatype;

ALTER TABLE [table-name] MODIFY [column-name] datatype;

SHOW TABLES;

INSERT INTO [table-name] (field1, field2,..) VALUES (value1,value2,..); INSERT INTO [table-name] (field1, field2,..) SELECT (field1,field2,.);


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b) Select statement

Ex: SELECT colA, colB FROM mytable; SELECT colA, colB FROM mytable WHERE colA= condition;

c) Delete Statement

Ex: DELETE FROM tblstudents WHERE studentid=001;

d) Update Statement

Ex: UPDATE tblstudent SET dob=1980-11-21 WHERE studentid=001;

SELECT [ALL | DISTINCT | DISTINCTROW] [Select expression ..] FROM [tables] WHERE [condition] GROUP BY [column name] HAVING [where condition] ORDER BY {column name} [ASC | DESC] LIMIT {[offset,] row_count};

DELETE FROM table-name WHERE condition;

UPDATE table-name SET column-name= WHERE condition;


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Chapter 10:

1. How to connect to php with mysql database server?

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:

Parameters: servername: is the name if IP address of server that contain Mysql server. username: is the username of Mysql server. password: is the password to log in.

Ex:connect.php

a) How to close connection

Ex:close_connect.php

PHP MySQL Database Connection

mysql_connect(servername,username,password);

mysql_close($connection);


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b) How to select database

Ex: select_database.php

c) How to manipulate data from php with mysql

This function is used to execute SQL command

How to insert data into Mysql When data is put into a MySQL table it is referred to as inserting data. When inserting data

it is important to remember the exact names and types of the table's columns.

Ex: insertdata.php

Field Name Data type id int(3) name varchar(50) sex varchar(7) dob date

mysql_select_db();

mysql_query(sql statement);

tblstudents


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How select data from Mysql

There are two functions to select data from Mysql table.

Syntax:

Execute query string.

- mysql_fetch_row(query string); - mysql_fetch_array(query string);


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Ex: select a record from database.

Ex: select all records from database.


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Chapter 11:

PHP Cookies

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 tag.

Syntax:

Ex1: In the example below, we will create a cookie named "user" and assign the value "Alex Porter" to it. We also specify that the cookie should expire after one hour:

Ex: cookie.php

Note: The value of the cookie is automatically URLencoded when sending the cookie, and automatically decoded when received (to prevent URLencoding, use setrawcookie() instead).

PHP cookies and sessions

setcookie(name, value, expire, path, domain);

.....


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Ex2: You can also set the expiration time of the cookie in another way. It may be easier than using seconds.

cookie2.php

In the example above the expiration time is set to a month (60 sec * 60 min * 24 hours * 30 days).

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:

read_cookie.php

In the following example we use the isset() function to find out if a cookie has been set:

isset_cookie.php

.....


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How to Delete a Cookie?

When deleting a cookie you should assure that the expiration date is in the past.

Ex: delete_cookie.php

PHP Sessions

A PHP session variable is used to store information about, or change settings for a user session. Session variables hold information about one single user, and are available to all pages in one application.

PHP Session Variables

When you are working with an application, you open it, do some changes and then you close it. This is much like a Session. The computer knows who you are. It knows when you start the application and when you end. But on the internet there is one problem: the web server does not know who you are and what you do because the HTTP address doesn't maintain state.

A PHP session solves this problem by allowing you to store user information on the server for later use (i.e. username, shopping items, etc). However, session information is temporary and will be deleted after the user has left the website. If you need a permanent storage you may want to store the data in a database.

Sessions work by creating a unique id (UID) for each visitor and store variables based on this UID. The UID is either stored in a cookie or is propagated in the URL.

Starting a PHP Session

Before you can store user information in your PHP session, you must first start up the session.

Note: The session_start() function must appear BEFORE the tag:


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Ex1: session.php

The code above will register the user's session with the server, allow you to start saving user information, and assign a UID for that user's session.

Storing a Session Variable

The correct way to store and retrieve session variables is to use the PHP $_SESSION variable:

Ex1: set-read-session.php

In the example below, we create a simple page-views counter. The isset() function checks if the "views" variable has already been set. If "views" has been set, we can increment our counter. If "views" doesn't exist, we create a "views" variable, and set it to 1:


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Ex2: isset-session.php

Destroying a Session

If you wish to delete some session data, you can use the unset() or the session_destroy() function.

The unset() function is used to free the specified session variable:

Ex:delete_session.php

You can also completely destroy the session by calling the session_destroy() function:

Note: session_destroy() will reset your session and you will lose all your stored session data.


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Chapter 12:

Server Side Includes (SSI)

You can insert the content of one PHP file into another 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:

include() generates a warning, but the script will continue execution require() generates a fatal error, and the script will stop

These two functions are used to create functions, headers, footers, or elements that will be reused on multiple pages.

Server side includes saves a lot of work. This means that you can create a standard header, footer, or menu file for all your web pages. When the header needs to be updated, you can only update the include file, or when you add a new page to your site, you can simply change the menu file (instead of updating the links on all your web pages).

PHP include() Function

The include() function takes all the content in a specified file and includes it in the current file. If an error occurs, the include() function generates a warning, but the script will continue execution.

Ex: Assume that you have a standard header file, called "header.php". To include the header file in a page, use the include() function:

PHP Include and Require

Welcome to my home page! Some text.


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Ex2: Assume we have a standard menu file, called "menu.php", that should be used on all pages:

All pages in the Web site should include this menu file. Here is how it can be done:

PHP require() Function

The require() function is identical to include(), except that it handles errors differently.

If an error occurs, the include() function generates a warning, but the script will continue execution. The require() generates a fatal error, and the script will stop.

Error Example include() Function

Home Tutorials References Examples About Us Contact Us

Welcome to my home page. Some text.


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Error message:

Notice: that the echo statement is executed! This is because a Warning does not stop the script execution.

Error Example require() Function

Now, let's run the same example with the require() function.

Error message:

The echo statement is not executed, because the script execution stopped after the fatal error.

It is recommended to use the require() function instead of include(), because scripts should not continue after an error.

Warning: include(wrongFile.php) [function.include]: failed to open stream: No such file or directory in C:\home\website\test.php on line 5

Warning: include() [function.include]: Failed opening 'wrongFile.php' for inclusion (include_path='.;C:\php5\pear') in C:\home\website\test.php on line 5

Warning: require(wrongFile.php) [function.require]: failed to open stream: No such file or directory in C:\home\website\test.php on line 5

Fatal error: require() [function.require]: Failed opening required 'wrongFile.php' (include_path='.;C:\php5\pear') in C:\home\website\test.php on line 5


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Reference Book

Julie C. Meloni (2000), PHP Fast & Easy Web Development, Prentice-Hall of India.

Bill McCarty (2001), PHP4: A Beginners Guide, Osborne/McGraw-Hill

Web Application Development (1)

Documents

php function chapter

php forms chapter

php operators

php introduction

php cookies

php constants

php fits

php file