6
PHP Components
PHP is one of the most popular development languages for building dynamic web
applications today. PHP offers many advantages; it is fast, stable, secure, easy to use and
open source. Being familiar with PHP and having a good toolbox for working effectively
with PHP is essential for most Web Developers because you will run into some PHP code
anyone will run into PHP now and then!
In this chapter we will discuss some of useful PHP Components that you can use to test,
develop Graphics, debug and deploy your PHP applications
6.1 GD Library
The GD library is used for dynamic image creation. From PHP we use with the GD library to
create GIF, PNG or JPG images instantly from our code. This allows us to do things such as
create charts on the fly, created an anti-robot security image, create thumbnail images, or
even build images from other so, the GD library allows you to alter, manipulate, and create
images quite simply. Today, we’ll learn the basics of using PHP and the GD library
You will need to make sure the GD library is installed and activated on your server. Don’t
know how to do this? No worries, just create a PHP file on your server and type in.
<?php echo phpinfo(); ?>
Now access the page in your browser and you’ll see a giant list detailing the features of your
version of PHP. Scroll down a bit and look for the ‘GD’ heading to make sure it is enabled. If
it is not, you will need to contact your hosting company. Luckily, most servers I have worked
on already have the GD library installed and activated.
6.1.1 imagecreate()
Create a new palette based image or you can say it creates and set a blank canvas,
imagecreate() returns an image identifier representing a blank image of specified size.
Syntax
resource imagecreate ( int $width , int $height )
$width
set’s image width
$height
set’s image height
Returns an image resource identifier on success, False on error
Example
<?php
$canvas=imagecreate(200,200)
?>
Above example will not display anything it will just create a canvas of 200 width and 200
height of that canvas, how to fill that canvas and draw any image like circle, rectangle will
be possible using different functions lets see them one by one.
6.1.2 imagecolorallocate()
Allocate a color for an image, imagecolorallocate() must be called to create each color that is
to be used in the image represented by image.
Imagecolorallocate() Returns a color identifier representing the color composed of the
given RGB components.
Syntax
int imagecolorallocate ( resource $image , int $red , int $green , int $blue )
image
An image resource, returned by one of the image creation functions, such as
imagecreate()
red
value of red component
green
value of green component
blue
value of blue component
These parameters are integers between 0 and 255 or hexadecimals between 0x00 and 0xFF.
Example
<?php
image = imagecreate(125, 125);
&height
//create basic image canvas of 125 width
$blue = imagecolorallocate($image, 0, 0, 255);
imagepng($image);
?>
//Set the background color
//save the image as a png and output
Output
Figure 6.1 example of imagecolorallocate()
6.1.3 imageline()
Draws a line between the two given points.
Syntax
bool imageline ( resource $image , int $x1 , int $y1 , int $x2 , int $y2 , int $color )
image An image resource, returned by one of the image creation functions such as
imagecreate()
x1
x coordinate for first point.
y1
y-coordinate for first point.
x2
x-coordinate for second point.
y2
y-coordinate for second point
color A color identifier created with imagecolorallocate()
Returns TRUE on success or FALSE on failure.
Example
<?php
// Create a 200 x 200 image
$canvas = imagecreate(200, 200);
// Allocate colors
$black=imagecolorallocate($canvas,255,255,0);
$pink = imagecolorallocate($canvas, 255, 105, 180);
$white = imagecolorallocate($canvas, 255, 255, 255);
$red = imagecolorallocate($canvas, 255, 0, 0);
imageline ($canvas,5, 5, 195, 5, $red);
imageline ($canvas,5, 5, 195, 195, $pink);
imagejpeg($canvas);
imagedestroy($canvas);
?>
Output
Figure 6.2 example of imageline()
6.1.4 Imagerectangle()
imagerectangle() creates a rectangle starting at the specified coordinates. Returns TRUE on
success or FALSE on failure.
Syntax
bool imagerectangle ( resource $image , int $x1 , int $y1 , int $x2 , int $y2 , int $color
)
image An image resource, returned by one of the image creation functions such as
imagecreate()
x1
Upper left x coordinate
y1
Upper left y coordinate
x2
Bottom right x coordinate
y2
Bottom right y coordinate
color A color identifier created with imagecolorallocate()
Example
<?php
// Create a 200 x 200 image
$canvas = imagecreate(200, 200);
// Allocate colors
$black=imagecolorallocate($canvas,0,0,0);
$pink = imagecolorallocate($canvas, 255, 105, 180);
$white = imagecolorallocate($canvas, 255, 255, 255);
$red = imagecolorallocate($canvas, 255, 0, 0);
// Draw three rectangles each with its own color
imagerectangle($canvas, 50, 50, 150, 150, $pink);
imagerectangle($canvas, 60, 60,140,140 , $white);
imagerectangle($canvas, 70, 70,130,130 , $red);
imagejpeg($canvas);
?>
Output
Figure 6.3 Example of imagerectangle()
6.1.5 Imagefilledrectangle()
Creates a rectangle filled with color in the given image starting at point 1 and ending at point
2. 0, 0 is the top left corner of the image.
Syntax
bool imagefilledrectangle ( resource $image , int $x1 , int $y1 , int $x2 , int $y2 , int $color )
image An image resource, returned by one of the image creation functions such as
imagecreate()
x1
x-coordinate for point 1.
y1
y-coordinate for point 1.
x2
x-coordinate for point 2.
y2
y-coordinate for point 2
color A color identifier created with imagecolorallocate()
Example
<?php
$canvas = imagecreate(200, 200) or die("Cannot Initialize new GD image stream");
$background_color = imagecolorallocate($canvas, 255, 255, 0); // yellow
$red = imagecolorallocate($canvas, 255, 0, 0);
$blue = imagecolorallocate($canvas, 0, 0, 255);
// red
// blue
imagerectangle ($canvas, 5, 10, 195, 50, $red);
imagefilledrectangle ($canvas, 5, 100, 195, 140, $blue);
imagepng($canvas);
?>
Output
Figure 6.4 example of imagefilledrectangle()
6.1.6 imageellipse()
Draws an ellipse centered at the specified coordinates
Syntax
bool imageellipse ( resource $image , int $cx , int $cy , int $width , int $height , int $color )
image An image resource, returned by one of the image creation functions such as
imagecreate()
cx
x coordinat of the center
cy
y-coordinate of the center.
Width The ellipse width
Height The ellipse height
color A color identifier created with imagecolorallocate()
Returns TRUE on success or FALSE on failure.
Example
<?php
// Create a blank image.
$image = imagecreate(400, 300);
$background_color = imagecolorallocate($image, 255, 255,255); // white
$col_ellipse = imagecolorallocate($image, 255, 0, 0);//Choose a color for the ellipse
imageellipse($image, 200, 150, 300, 200, $col_ellipse);// Draw the ellipse.
imagepng($image);
?>
Output
Figure 6.5 example of imageellipse()
6.1.7 imagefilledellipse()
Draws an ellipse centered at the specified coordinate on the given image. Its Returns TRUE
on success or FALSE on failure.
Syntax
bool imagefilledellipse ( resource $image , int $cx , int $cy , int $width , int $height , int
$color )
image
cx
cy
Width
An image resource, returned by one of the image creation functions such as
imagecreate()
x coordinat of the center
y-coordinate of the center.
The ellipse width
Height
color
The ellipse height
A color identifier created with imagecolorallocate()
Example
<?php
$canvas = imagecreate(200, 200) or die("Cannot Initialize new GD image stream");
$background_color = imagecolorallocate($canvas, 255, 255, 0); // yellow
$red = imagecolorallocate($canvas, 255, 0, 0);
// red
$blue = imagecolorallocate($canvas, 0, 0, 255);
// blue
imageellipse($canvas, 50, 50, 40, 60, $red);
imagefilledellipse($canvas, 150, 150, 60, 40, $blue);
imagepng($canvas);
?>
Output
Figure 6.6 example of imagefilledellipse()
6.1.8 imagearc()
imagearc() draws an arc of circle centered at the given coordinates, its return true on success,
false on failure
bool imagearc ( resource $image , int $cx , int $cy , int $width , int $height , int $start
, int $end , int $color )
image
cx
cy
width
height
start
end
color
Example
<?php
An image resource, returned by one of the image creation functions such as
imagecreate()
x coordinat of the center
y-coordinate of the center.
The ellipse width
The ellipse height
the arc start angle, in degree
The arc end angle, in degrees. 0° is located at the three-o'clock position, and
the arc is drawn clockwise.
A color identifier created with imagecolorallocate()
$im = imagecreate(200, 200) or die("Cannot Initialize new GD image stream");
$background_color = imagecolorallocate($im, 255, 255, 0); // yellow
$red = imagecolorallocate($im, 255,0,0);
$blue = imagecolorallocate($im, 0, 0, 255);
$green = imagecolorallocate($im, 0, 255, 0);
$sky = imagecolorallocate($im, 100, 255,255);
imagearc($im, 20, 50, 40, 80, 0, 90, $red);
imagearc($im, 70, 50, 40, 80, 0, 180, $green);
imagearc($im, 120, 50, 40, 80, 0, 270, $blue);
imagearc($im, 170, 50, 40, 80, 0, 360, $sky);
imagepng($im);
// red
// blue
?>
Ouput
Figure 6.7 example of imagearc()
X and Y define thy position of the center of the arc within the image, Width and height are
the dimensions of the complete circle formed by the arc. arc start and arc end are the start and
the end of the arc in degrees. If start is zero, as in the example, the figure will start in the
right.
6.1.9 imagefilledarc()
Draws a partial arc centered at the specified coordinate in the given image.
Syntax
bool imagefilledarc ( resource $image , int $cx , int $cy , int $width , int $height , int
$start , int $end , int $color , int $style )
image
cx
cy
width
height
start
end
color
Style
An image resource, returned by one of the image creation functions such as
imagecreate()
x coordinat of the center
y-coordinate of the center.
The ellipse width
The ellipse height
the arc start angle, in degree
The arc end angle, in degrees. 0° is located at the three-o'clock position, and
the arc is drawn clockwise.
A color identifier created with imagecolorallocate()
Style we can specify four value
IMG_ARC_PIE
IMG_ARC_CHORD
IMG_ARC_NOFILL
IMG_ARC_EDGED
IMG_ARC_PIE and IMG_ARC_CHORD are mutually exclusive; IMG_ARC_CHORD just
connects the starting and ending angles with a straight line, while IMG_ARC_PIE produces a
rounded edge. IMG_ARC_NOFILL indicates that the arc or chord should be outlined, not
filled. IMG_ARC_EDGED, used together with IMG_ARC_NOFILL, indicates that the
beginning and ending angles should be connected to the center - this is a good way to outline
(rather than fill) a 'pie slice'.
Example
<?php
// create a 200*200 image
$img = imagecreate(200, 200);
$white = imagecolorallocate($img, 255,255, 255);
// allocate some colors
$black = imagecolorallocate($img, 0, 0, 0);
$red = imagecolorallocate($img, 255, 0, 0);
$green = imagecolorallocate($img, 0, 255, 0);
$blue = imagecolorallocate($img, 0, 0, 255);
$yellow = imagecolorallocate($img, 255, 255, 0);
// draw the head
imagearc($img, 100, 100, 200, 200, 0, 360, $black);
imagefilledarc($img,100,100,200,200,0,360,$yellow,IMG_ARC_PIE );
// mouth
imagearc($img, 100, 100, 150, 150, 25, 155, $red);
// left and then the right eye
imagearc($img, 60, 75, 50, 50, 0, 360, $green);
imagearc($img, 140, 75, 50, 50, 0, 360, $blue);
imagefilledarc($img,70,75,25,25,0,360,$black,IMG_ARC_PIE );
imagefilledarc($img,130,75,25,25,0,360,$black,IMG_ARC_PIE );
imagepng($img);
?>
Ouptut
Figure 6.8 example of imagefilledarc()
6.1.10 imagepolygon()
imagepolygon() creates a polygon in the given image.
Syntax
bool imagepolygon ( resource $image , array $points , int $num_points , int $color )
image
points
num_points
color
An image resource, returned by one of the image creation functions such as
imagecreate()
An array containing the polygon's vertices
points[0]= x0
points[1]= y0
points[2]= x1
points[3]= y1
Total number of points
A color identifier created with imagecolorallocate()
6.1.11 imagefilledpolygon()
imagefilledpolygon() creates a filled polygon in the given image
Syntax
bool imagefilledpolygon ( resource $image , array $points , int $num_points , int
$color )
image
An image resource, returned by one of the image creation functions such as
imagecreate()
points
num_points
color
An array containing the polygon's vertices
points[0]= x0
points[1]= y0
points[2]= x1
points[3]= y1
Total number of points
A color identifier created with imagecolorallocate()
Example of imagepolygon() and imagefilledpolygon()
<?php
// Create a blank image
$image = imagecreatetruecolor(400, 300);
// Allocate a color for the polygon
$blue = imagecolorallocate($image, 0, 0, 255);
// Draw the polygon
imagepolygon($image, array(
0, 0,
100, 200,
300, 200 ),3,$col_poly);
imagefilledpolygon($image, array(
0, 0,
100, 200,
300, 200 ),3,$blue);
//fill the polygon with specified color
imagepng($image);
?>
Figure 6.9 example of imagepolygon() & imagefilledpolygon()
6.1.12 imagestring()
Draw a string at a given coordinates
Syntax
bool imagestring ( resource $image , int $font , int $x , int $y , string $string , int $color )
image
font
x
y
String
color
An image resource, returned by one of the image creation functions such as
imagecreate()
Can be 1, 2, 3, 4, 5 for built-in fonts in latin2 encoding
x-coordinate of the upper left corner
y-coordinate of the upper left corner.
The string to be written.
A color identifier created with imagecolorallocate()
Example
<?php
// Create a 100*30 image
$im = imagecreate(350, 30);
// purple background and blue text
$bg = imagecolorallocate($im, 150, 0,255);
$textcolor = imagecolorallocate($im, 0, 0, 255);
// Write the string at the top left
imagestring($im, 5, 0, 0, 'Welcome to PHP GD Library Function!', $textcolor);
// Output the image
header('Content-type: image/png');
imagepng($im);
imagedestroy($im);
?>
Output
Figure 6.10 example of imagestring()
6.1.13 imagerotate()
Rotates the image image using the given angle in degrees, The center of rotation is the center
of the image, and the rotated image may have different dimensions than the original image.
Syntax
resource imagerotate ( resource $image , float $angle , int $bgd_color [, int
$ignore_transparent = 0 ] )
image
An image resource, returned by one of the image creation functions such as
imagecreate()
angle
Rotation angle, in degrees. The rotation angle is interpreted as the number of
degrees to rotate the image anticlockwise. Values may be positive (90, 180...)
or negative (-90,-180...).
bgd_color
Specifies the color of the uncovered zone after the rotation, $color indicates
the color to be used as background when necessary (when rotation angle is different to 90,
180
and
270).
For example when rotation is 45 degrees, the size of the figure will be altered, as shown
bellow. As a consequence a background color is required to fill the new surface.
Returns an image resource for the rotated image, or FALSE on failure
Example
<?php
// Create a 100*30 image
$im = imagecreate(350, 30);
// purple background and blue text
$bg = imagecolorallocate($im, 150, 0,255);
$textcolor = imagecolorallocate($im, 0, 0, 255);
// Write the string at the top left
imagestring($im, 5, 0, 0, 'Welcome to PHP GD Library Function!', $textcolor);
$rotate = imagerotate($im,45,$bg);
imagepng($rotate);
?>
Output
Figure 6.11 example of imagerotate()
6.1.14 imagepng()
Outputs or saves a PNG image from the given image.
Syntax
bool imagepng ( resource $image [, string $filename [, int $quality]])
image
An image resource, returned by one of the image creation functions, such as
imagecolor()
filename
The path to save the file to. If not set or NULL, the raw image stream will be
outputted directly.
quality
Compression level: from 0 (no compression) to 9.
Example
<?php
$im = imagecreate(100,100);
$bg=imagecolorallocate($im,0,0,255);
imagepng($im);
?>
imagepng() will save the info at $im (the image) in the file "image.png". Other image types
may be created by using commands imagegif()-save file in gif format, imagewbmp() save
file in wbmp format, imagejpeg() save file in jpeg format.
6.1.15 imagedestroy()
imagedestroy() frees any memory associated with image image.
Syntax
bool imagedestroy ( resource $image )
image
An image resource, returned by one of the image creation functions such as
imagecreate()
Returns TRUE on success or FALSE on failure
Example
<?php
$im = imagecreate(100,100);
$bg=imagecolorallocate($im,0,0,255);
imagepng($im);
imagedestroy($im);
?>
6.2
Regular expression in PHP
Regular expressions are a powerful tool for examining and modifying text. Regular
Expression commonly known as RegEx. Regular expressions themselves, with a general
pattern notation almost like a mini programming language, allow you to describe and parse
text. They enable you to search for patterns within a string, extracting matches flexibly and
precisely. However, you should note that because regular expressions are more powerful,
they are also slower than the more basic string functions. You should only use regular
expressions if you have a particular need.
The regular expression, as a pattern, can match all kinds of text strings helping your
application validate, compare, compute, decide etc. It can do simple or very complex string
manipulations. The list of possibilities is enormous when it comes to what you can achieve
using regular expressions. You can take any phrase that starts with an "A" or any character
and do various things with it. You can match phone numbers, email addresses, url's, credit
card numbers, social security numbers, zip codes, states, cities.....(the list never ends). A huge
script that is supposed to validate a user input and prepare it for sql can be reduced to only
one line with the help of regular expression.
Regular expressions started out as a feature of the Unix shell. They were designed to make it
easier to find, replace and work with strings — and since their invention, they’ve been in
wide use in many different parts of Unix based Operating Systems. They were commonly
used in Perl, and since then have been implemented into PHP.
Regular expression types
There are 2 types of regular expressions
 POSIX Extended
 Perl Compatible
The ereg, eregi, ... are the POSIX versions and preg_match, preg_replace, ... are the Perl
version. It is important that using Perl compatible regular expressions (PCRE) the expression
should be enclosed in the delimiters, a forward slash (/), for example. However this version is
more powerful and faster as well than the POSIX one.
The regular expressions basic syntax
To use regular expressions first you need to learn the syntax of the patterns. We can group the
characters inside a pattern like this
 Normal characters which match themselves like hello
 Start and end indicators as ^ and $
 Count indicators like +,*,?
 Logical operator like |
 Grouping with {},(),[]
A regular expression is a pattern of text that consists of ordinary characters (for example,
letters a through z) and special characters, known as metacharacters. The pattern describes
one or more strings to match when searching a body of text. The regular expression serves as
a template for matching a character pattern to the string being searched.
Now let's see a detailed pattern syntax reference
RegEx
Match
Not match
Description
(pattern) (subject)
(subject)
Match if the pattern is present anywhere
world
Hello world Hello Jim
in the subject
Match if the pattern is present at the
^world
world class Hello world
beginning of the subject
Match if the pattern is present at the end
world$
Hello world world class
of the subject
world/i
This WoRLd Hello Jim
Makes a search in case insensitive mode
^world$ world
Hello world The string contains only the "world"
worl, world,
world*
wor
There is 0 or more "d" after "worl"
worlddd
world,
world+
worl
There is at least 1 "d" after "worl"
worlddd
worl, world,
world?
wor, wory
There is 0 or 1 "d" after "worl"
worly
world{1} world
worly
There is 1 "d" after "worl"
world,
world{1,}
worly
There is 1 ore more "d" after "worl"
worlddd
world{2,3 worldd,
world
There are 2 or 3 "d" after "worl"
}
worlddd
wo, world,
wo(rld)*
wa
There is 0 or more "rld" after "wo"
worldold
earth|worl
The string contains the "earth" or the
earth, world sun
d
"world"
w.rld
world, wwrld wrld
Any character in place of the dot.
^.{5}$
world, earth sun
A string with exactly 5 characters
[abc]
abc, bbaccc sun
There is an "a" or "b" or "c" in the string
There are any lowercase letter in the
[a-z]
world
WORLD
string
world,
There are any lower- or uppercase letter in
[a-zA-Z] WORLD,
123
the string
Worl12
[^wW]
\d
\D
\s
earth
w, W
The actual character cannot be a "w" or
"W"
123
abc
Matches a digit character.
abc
123
Matches a nondigit character.
“ “(space)
Abc, 123
Matches any whitespace character
including space, tab, form-feed, etc.
\S
\w
\W
abc,123
“ “(space)
Matches any non-whitespace character
abc_xyz
123
Matches any word character including
underscore
123
abc_xyz
Matches any nonword character
6.2.1 Perl Compatible Regular Expression
Perl-Compatible Regular Expressions emulate the Perl syntax for patterns, which means that
each pattern must be enclosed in a pair of delimiters. Usually, the slash (/) character is used.
For instance, /pattern/.
The PCRE functions can be divided in several classes: matching, replacing, splitting and
filtering
preg_match()
The preg_match() function searches string for pattern, returning true if pattern exists, and
false otherwise.
Syntax
int preg_match ( string $pattern , string $subject [, array &$matches [, int $flags = 0 [,
int $offset = 0 ]]] )
$pattern
pattern to search in string
$subject
input string, from which pattern will search
$matches
If matches is provided, then it is filled with the results of search. $matches[0]
will contain the text that matched the full pattern, $matches[1] will have the
text that matched the first captured parenthesized subpattern.
flags can set PREG_OFFSET_CAPTURE
If this flag is set, for every occurring match the appending string with
offset(index) will also be returned.
we can specify the index from where start the search, by default it will start
from index 0
$flag
$offset
Example
<?php
$subject = "abcdef";
$pattern = '/def/';
preg_match($pattern, $subject, $matches);
print_r($matches);
?>
Output
Array ( [0] => def )
In above example preg_match() search pattern def in $Subject, $matches is array variable
which stores array if pattern matches, above def is match from string “abcdef”, it will store
matches part. ie “def”.
<?php
$subject = "defxyzdef";
$pattern = '/def/';
preg_match($pattern, $subject, $matches, PREG_OFFSET_CAPTURE, 3);
print_r($matches);
?>
Output
Array ( [0] => Array ( [0] => def [1] => 6 ) )
In this example PREG_OFFSET_CAPTURE is specified means $matches array variable will
store match pattern as well as index of that match above example [1]=>6 represents the
index of the def from $subject. and last parameter offset is set 3 means Subject “defxyzdef”
there are two matches by default it will search def with index 0, but we have specify the
offset 3 so it will start search from position 3 and match def which is on index 6.
preg_match_all()
The preg_match_all() function matches all occurrences of pattern in string. After the first
match is found, the subsequent searches are continued on from end of the last match, Returns
the number of full pattern matches (which might be zero), or FALSE if an error occurred.
Syntax
int preg_match_all ( string $pattern , string $subject [, array &$matches [, int $flags =
PREG_PATTERN_ORDER [, int $offset = 0 ]]] )
$pattern
$subject
$matches
$flag
$offset
pattern to search in string
input string, from which pattern will search
If matches is provided, then it is filled with the results of search. $matches[0]
will contain the text that matched the full pattern, $matches[1] will have the
text that matched the first captured parenthesized subpattern.
flags can set
PREG_PATTERN_ORDER—(Default flag) Orders results so that
$matches[0] is an array of full pattern matches, $matches[1] is an array of
strings matched by the first parenthesized subpattern, and so on
PREG_SET_ORDER --Orders results so that $matches[0] is an array of first
set of matches, $matches[1] is an array of second set of matches, and so on.
PREG_OFFSET_CAPTURE--If this flag is set, for every occurring match the
appending string with offset (index) will also be returned.
we can specify the index from where start the search, by default it will start
from index 0
Example
<?php
$subject = "defxyzdefabcdef";
$pattern = '/def/';
preg_match_all($pattern, $subject, $matches,PREG_PATTERN_ORDER);
print_r($matches);
?>
Output
Array ( [0] => Array ( [0] => def [1] => def [2] => def ) )
In above example preg_match_all() matches all pattern from the string,
$matches array variable will store match pattern as well as index of that match,
PREG_PATTERN_ORDER will Orders results so that $matches[0] is an array of full pattern
matches, $matches[1] is an array of strings matched.
Now try same example with flag PREG_SET_ORDER.
preg_match_all($pattern, $subject, $matches, PREG_SET_ORDER);
Output
Array ( [0] => Array ( [0] => def ) [1] => Array ( [0] => def ) [2] => Array ( [0] =>
def ) )
PREG_SET_ORDER Orders results so that $matches[0] is an array of first set of matches,
$matches[1] is an array of second set of matches, and so on.
Now try same example with flag PREG_OFFSET_CAPTURE
preg_match_all ($pattern, $subject, $matches, PREG_OFFSET_CAPTURE )
Ouptut
Array ( [0] => Array ( [0] => Array ( [0] => def [1] => 0 )
[1] => Array ( [0] => def [1] => 6 )
[2] => Array ( [0] => def [1] => 12 ) ) )
PREG_OFFSET_CAPTURE return every occurring match the appending string with offset
(index) will also be returned.
preg_replace()
preg_replace() search and replace the string, Searches subject for matches to pattern and
replaces them with replacement, preg_replace() returns an array if the subject parameter is an
array, or a string otherwise. If matches are found, the new subject will be returned, otherwise
subject will be returned unchanged or NULL if an error occurred.
Syntax
mixed preg_replace ( mixed $pattern , mixed $replacement , mixed $subject [, int
$limit = -1 [, int &$count ]] )
$pattern
The pattern to search for
$replacement The string or an array with strings to replace
$subject
The string or an array with strings to search and replace. If subject is an array,
then the search and replace is performed on every entry of subject, and the
return value is an array as well.
$limit
The maximum possible replacements for each pattern in each subject string.
Defaults to -1 (no limit).
count
If specified, this variable will be filled with the number of replacements done
Example
<?php
$num = 4;
$string = "This string has four words.";
$string = preg_replace('/four/', $num, $string);
echo $string;
?>
Output
This string has 4 words.
In above example it will search pattern four and replace with 4 in $string.
Example
<?php
$string = '2007-01-15';
$pattern = '/(\d+)-(\d+)-(\d+)/';\\ \d represents number only so pattern match with
string
$replacement = '$2/$3/$1';
echo preg_replace($pattern, $replacement, $string);
//$0 will represent the whole string
?>
Output
01/15/2007
In above example replacement may contain references of the form \\n or $n. Every such
reference will be replaced by the text captured by the n'th parenthesized pattern. n can be
from 0 to 99, and \\0 or $0 refers to the text matched by the whole pattern. Opening
parentheses are counted from left to right (starting from 1) to obtain the number of the
capturing subpattern. so as per our example $0 represents whole string, $1 represents 2007
and $3 represents 15, '$2/$3/$1' using this replacement we are changing the order of the
string and adding “/” instead of “–“.
Example
<?php
$count = 0;
echo preg_replace(array('/\d/', '/\s/'), '*', 'xp 4 to', -1 , $count);
echo $count; //3
?>
Ouput
xp***to3
In above example pattern search for \d,\s mean numbers and white space will search, it will
replace number and space into *, -1 represents limit by default is -1 indicating the maximum
possible replacement is to do. $count will return number of replacement has done. so it return
3.
Example
<?php
$count = 0;
$a=preg_replace(array('/\d/', '/\s/'), '*', array('xp 4 to','he ll o'), 3 , $count);
print_r($a);
echo $count; //3
?>
Output
Array ( [0] => xp***to [1] => he*ll*o ) 5
In this example subject is an array so preg_replace will return array.
preg_split()
Split the given string by a regular expression, Returns an array containing substrings of
subject split along boundaries matched by pattern.
Syntax
array preg_split ( string $pattern , string $subject [, int $limit = -1 [, int $flags = 0 ]] )
pattern
The pattern to search for, as a string.
subject
limit
flags
The input string.
If specified, then only substrings up to limit are returned with the rest of the
string being placed in the last substring. A limit of -1, 0 or null means "no
limit.
flag can set following possibilities.
PREG_SPLIT_NO_EMPTY-If this flag is set, only non-empty pieces will be
returned by preg_split().
PREG_SPLIT_OFFSET_CAPTURE - If this flag is set, for every occurring
match the appending string with offset (index) will also be returned.
Example
<?php
$string = "aBBBaCCCADDDaEEEaGGGA";
$chunks = preg_split ("/a/", $string, 5);
print_r($chunks);
?>
Output
Array ( [0] => [1] => BBB [2] => CCCADDD [3] => EEE [4] => GGGA )
In above example pattern will search “a” in string, wherever preg_split find a it start spilting
process.
Same example with flag PREG_SPLIT_NO_EMPTY, it will remove all empty pieces from
preg_split returns
$chunks = preg_split ("/a/", $string, 5,PREG_SPLIT_NO_EMPTY);
Output
Array ( [0] => BBB [1] => CCCADDD [2] => EEE [3] => GGGA )
preg_gerp()
preg_grep function is similar to pre_match() it will match the pattern, but preg_match will
only search pattern in string where as preg_grep will search pattern in array, and it will
returns the array consisting of the elements of the input array that match the given pattern.
Syntax
array preg_grep ( string $pattern , array $input [, int $flags = 0 ] )
pattern
input
flags
The pattern to search for, as a string.
The input array.
If set to PREG_GREP_INVERT, this function returns the elements of the
input array that do not match the given pattern.
Example
<?php
$n=array('john','partric','amy');
$result=preg_grep('/^[a-m]/',$n);
print_r($result);
?>
Output
Array ( [0] => john [2] => amy )
In above program preg_grep first match the pattern ^ represents starting of the string, so
stastring must be in between small a-m so it match john and amy.
Same example with flag PREG_GREP_INVERT, it will return opposite of preg_grep search
$result=preg_grep('/^[a-m]/',$n, PREG_GREP_INVERT);
Output
Array ( [1] => partric )
preg_quote()
preg_quote() takes string and puts a backslash in front of every character that is part of the
regular expression syntax. This is useful if you have a run-time string that you need to match
in some text and the string may contain special regex characters. and it returns the quoted
string.
Syntax
string preg_quote ( string $str [, string $delimiter = NULL ] )
str
delimiter
The input string.
If the optional delimiter is specified, it will also be escaped. This is useful for
escaping the delimiter that is required by the PCRE functions. The / is the
most commonly used delimiter.
Example
<?php
$keywords = '$40 for a g3/400';
$keywords = preg_quote($keywords, '/');
echo $keywords; // returns \$40 for a g3\/400
?>
Output
\$40 for a g3\/400
6.2.2 POSIX Regular Expression
ereg()
ereg() function is similar to preg_match(), preg_match() was PCRE functions, while ereg() is
PSOIX function which searches a string for matches to the regular expression given in pattern
in a case-sensitive way, Returns the length of the matched string if a match for pattern was
found in string, or FALSE if no matches were found or an error occurred.
Syntax
int ereg ( string $pattern , string $string [, array &$regs ] )
pattern
Case sensitive regular expression.
string
The input string.
regs
If matches are found for parenthesized substrings of pattern and the function is
called with the third argument regs, the matches will be stored in the elements
of the array regs. $regs[1] will contain the substring which starts at the first
left parenthesis. $regs[2] will contain the substring starting at the second, and
so on. $regs[0] will contain a copy of the complete string matched.
Example
<?php
$zip = "[0-9]{5}";
$str = "Mission Viejo, CA 92692";
ereg($zip,$str,$regs);
print_r ($regs);
?>
Output
Array ( [0] => 92692 )
In above example [0-9]({5} indicates any number of 5 digits will search in string if found it
will stores $regs array variable.
eregi()
This function is identical to ereg() except that it ignores case distinction when matching
alphabetic characters. eregi() function returns the length of the matched string if a match for
pattern was found in string, or FALSE if no matches were found or an error occurred
Syntax
int eregi ( string $pattern , string $string [, array &$regs ] )
pattern
Case insensitive regular expression.
string
The input string.
regs
If matches are found for parenthesized substrings of pattern and the function is
called with the third argument regs, the matches will be stored in the elements
of the array regs. $regs[1] will contain the substring which starts at the first
left parenthesis. $regs[2] will contain the substring starting at the second, and
so on. $regs[0] will contain a copy of the complete string matched.
Example
<?php
$string = 'XYZ';
if (eregi('z', $string)) {
echo "'$string' contains a 'z' or 'Z'!";
}
?>
Output
'XYZ' contains a 'z' or 'Z'!
ereg_replace()
This function scans string for matches to pattern, and then replaces the matched text with
replacement. Its return the modified string is returned. If no matches are found in string, then
it will be returned unchanged string.
Syntax
string ereg_replace ( string $pattern , string $replacement , string $string )
pattern
pattern to match
replacement
The string which to replace
string
The input string
Example
<?php
$num = '4';
$string = "This string has four words.";
$string = ereg_replace('four', $num, $string);
echo $string;
?>
Output
This string has 4 words
In above example $num datatype is string ie ‘4’ because if 4 is there (integer datatype) then it
will return unchanged string because according to syntax replacement must be string.
eregi_replace()
This function is identical to ereg_replace() except that this ignores case distinction when
matching alphabetic characters.
Syntax
string eregi_replace ( string $pattern , string $replacement , string $string )
pattern
pattern to match
replacement
The string which to replace
string
The input string
Example
<?php
$num = '4';
$string = "This string has four words.";
$string = ereg_replace('FOUR', $num, $string);
echo $string;
?>
Output
This string has 4 words
split()
Splits a string into array by regular expression, and it returns an array of strings by the casesensitive regular expression pattern.
Syntax
array split ( string $pattern , string $string [, int $limit = -1 ] )
pattern
string
limit
pattern to search in Case sensitive.
The input string.
If limit is set, the returned array will contain a maximum of limit elements
with the last element containing the whole rest of string.
Example
<?php
$string = "ABBBaCCCADDDAEaEaGGGA";
$chunks = split ("a", $string,2);
print_r($chunks);
?>
Output
Array ( [0] => ABBB [1] => CCCADDDAEaEaGGGA )
In above example it will start splitting when pattern found “a” and limit is specify 2 so it
return 2
elements and rest whole string in last element and it will search case sensitive.
spliti()
This function is identical to split() except that this ignores case distinction when matching
alphabetic characters. , and it returns an array of strings by the case-insensitive regular
expression pattern.
Syntax
array spliti ( string $pattern , string $string [, int $limit = -1 ] )
pattern
string
limit
pattern to search in Case insensitive.
The input string.
If limit is set, the returned array will contain a maximum of limit elements
with the last element containing the whole rest of string.
Example
<?php
$string = "ABBBaCCCADDDAEaEaGGGA";
$chunks = spliti ("a", $string,5);
print_r($chunks);
?>
Output
Array ( [0] => [1] => BBB [2] => CCC [3] => DDD [4] => EaEaGGGA )
In above example it will start splitting when pattern found “a” or “A” and limit is specify 5 so
it return 5 elements and rest whole string in last element and it will search case insensitive
and it will not include “a” or “A” in output because it will start splitting from “a” or
“A”.
6.3 Cookies
A cookie is a text file used to represent a user of the website. Cookie is stored on the local
computer of the user. When you visit a website a cookie may be set to represent the user.
Next time he visits the website, he does not need to identify himself manually; instead the
cookie will represent him on that website. With the help of PHP, cookies can be created, read
and destroyed.
The main difference between a session and a cookie is that cookies are stored on the user’s
computer where as sessions are stored on the server for particular usage. Cookies can be
manually deleted by the users also to make sure security is not breached.
Use of cookies
We can literally put 4000 characters of data in a text cookie file and store information about
the user preferences for a particular website. Some of the practical uses of Cookies are as
follows
 Many sites use them to provide customized pages and results to their users. This can be
achieved by storing all the information like preferences etc in a cookie.
 Many websites use cookies to log their users in automatically. By storing a few pieces of
user information they can automatically authenticate the user's details and use them to save
the user time when they log in.
 Visitor tracking and statistics systems often use them to track visitors. By assigning the
visitor a cookie, they will not be counted more than once, so accurate unique visitor statistics
can be obtained.
Cookie Security
Cookie is just a flat text file, it can be opened and read on the computer it is stored in.
If a website has stored a password in a cookie it can be read and but if the same password is
encrypted using a hash like md5 () or sha1 () then it can be more secure since this content is
used to match it with the password stored on the website.
Set a Cookie
In PHP, we have a function setcookie() which is used to SET as well as UNSET the cookie.
The setcookie() function must appear BEFORE the <html> tag.
Syntax
setcookie("name", "value", expire, "path", "domain");
Name:
Value:
Expire:
Path:
Domain:
it’s the name of the cookie
the value that is to be stored in the cookie. Ex: username, password, email id
it’s the expiring time of the cookie since it was set.
the path of the website where the cookie is valid. Like a subdomain
The website this cookie is valid for.
Example
<?php
setcookie("username", "XYZ", time()+3600);
?>
In the above example, the Cookie name is username. value is XYZ, it expires in 1 hour. It is
mentioned in seconds 60 seconds multiplied by 60 minutes.
How to Retrieve a Cookie Value
PHP comes with a super global $_COOKIE. All cookies set by a website on their clients
website is retrieved via this super global.
Example
<?php
if (isset($_COOKIE["username"]))
{
echo $_COOKIE["username"];// Print a cookie
print_r($_COOKIE); // A way to view all cookies
}
else
echo "Cookie not created";
?>
Ouput
XYZArray ( [username] => XYZ )
The above script checks if the cookie with the name username is set. If it is set it prints the
cookie. If the cookie is not set then are just prints out cookie not created
Delete a Cookie
There is no special function to delete a cookie. It can be done by reversing the timing of
expiry in the cookie by resetting it again as shown below
setcookie("username", "", time()-3600);
From the above statement, if you observe the name of the cookie is the same as it was set.
The value of the cookie is set to NULL and the expiry time is subtracted from the current
time to 1 hour earlier making it to expire at the moment the above function is run.
Example
<?php
// set the expiration date to one hour ago
setcookie("username", "", time()-3600);
?>
So this way we can create, retrieve and delete the cookie. if we want to see the cookie created
we can and we can open cookie in any text editor, to view cookie Start
Runcookie
and press enter it will open folder named cookie, there you can view cookies created as text
file.
6.4
Session
Sessions are used to store information which can be used through-out the application for the
entire time the user is logged in or running the application. Each time a user visits your
website, you can create a session for that user to store information pertaining to that user.
Unlike other applications, in web applications, all the stored variables and objects are not
globally available throughout all pages (unless sent through POST or GET methods to the
next page), so to tackle this problem sessions are utilized.
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.
Create Session in PHP
In PHP, information is stored in session variables. Now let’s learn how we create a session in
PHP, before you can store any information in session variables, you must first start up the
session using the session_start() function. See below
Example
<?php
session_start();
?>
<html>
<body>
--------------------------------</body>
</html>
When you start a session a unique session id (PHPSESSID) for each visitor/user is created.
You can access the session id using the PHP predefined constant PHPSESSID. The code
above starts a session for the user on the server, and assigns a session id for that user's
session.
Storing information in session
To store information is a session variable, you must use the predefined session variable
$_SESSION.its create an associative array, using this you can store and retrieve session data.
Example
<?php
session_start();
$_SESSION['name'] = "Ronak"; // store session data
$_SESSION['age']="23";
echo "name=". $_SESSION['name'];
echo "<br>";
echo "age=". $_SESSION['age'];
?>
Output
name=Roank
age=23
Destroying Session
Sessions are destroyed automatically after user leaves your website or closes the browser, but
if you wish to clear a session variable yourself, you can simple use the unset() function to
clean the session variable or the session_destroy() function
unset()
unset() function is used to free the specified session variable
Example
<?php
session_start();
$_SESSION['name'] = "Ronak"; // store session data
$_SESSION['age']="23";
echo "name=". $_SESSION['name'];//retrieve the session value print Ronak
echo "<br>";
echo "age=". $_SESSION['age'];//print 23
echo "<br>"
unset($_SESSION['age']);//destroy session=age
echo "name=". $_SESSION['name'];//print Ronak
echo "<br>";
echo "age=". $_SESSION['age'];// print nothing because session is destroyed
?>
Ouput
name=Ronak
age=23
name=Ronak
age=
session_destroy()
session_destroy() will reset your session and you will lose all your session data.
Example
<?php
session_start();
session_destroy();
echo "name=". $_SESSION['name'];
echo "age=". $_SESSION['age'];
?>
Output
name=Ronak
age=23
Above example if session_destroy() is used then also it will print the session variable.
because session_destroy() will not remove the session until session is in use. when session
will get free at that time it will remove all session variable.try to refresh and run it will print
name=
age=
all session will destroy.
6.5 Server Variable
Server Variables are those variables which are inside the super global array named
$_SERVER available in PHP. There are many server variables in PHP and some of them are
very useful for developing PHP projects. All servers maintain a set of variables that provide
information such as where the user come from, and other useful information. You can access
these variables by name in PHP.
The $_SERVER variable is an associative array that you could iterate using the foreach
construct. The following example lists each of the variables, and the associated value.
example will list out all server variable.
Example
<?php
foreach($_SERVER as $key=>$value)
print $key . " = " . $value . "<br>";
?>
Output
DOCUMENT_ROOT = C:/xampp/htdocs
SERVER_ADMIN = postmaster@localhost
SCRIPT_FILENAME = C:/xampp/htdocs/xampp/test.php
SERVER_PROTOCOL = HTTP/1.1
REQUEST_METHOD = GET
QUERY_STRING =
REQUEST_URI = /xampp/test.php
SCRIPT_NAME = /xampp/test.php
In above example listed few of the server variable, let’s see variable and description of
variable in detail.
Server Variable
Description
PHP_SELF
The filename of the currently executing script,relative to
document root
SERVER_NAME
The name of the server host under which the current script is
SERVER_ADDR
SERVER_SOFTWARE
SERVER_PROTOCOL
REQUEST_METHOD
REQUEST_TIME
QUERY_STRING
DOCUMENT_ROOT
HTTP_ACCEPT
HTTP_ACCEPT_CHAR
SET
HTTP_ACCEPT_LANG
UAGE
HTTP_HOST'
HTTP_USER_AGENT
HTTPS
REMOTE_ADDR
REMOTE_HOST
REMOTE_PORT
SCRIPT_FILENAME
SERVER_ADMIN
SERVER_PORT
SCRIPT_NAME
REQUEST_URI
PHP_AUTH_USER
PHP_AUTH_PW
PATH_INFO
executing
The IP address of the server under which the current script is
executing.
Server identification string, given in the headers when
responding to requests
Name and revision of the information protocol via which the
page was requested; i.e. 'HTTP/1.0';
Which request method was used to access the page; i.e. 'GET',
'POST'.
The timestamp of the start of the request
The query string, if any, via which the page was accessed.
The document root directory under which the current script is
executing, as defined in the server's configuration file.
Contents of the Accept: header from the current request, if there
is one
Contents of the Accept-Charset: header from the current request,
if there is one. Example: 'iso-8859-1,*,utf-8'.
Contents of the Accept-Language: header from the current
request, if there is one. Example: 'en'.
Contents of the Host: header from the current request, if there is
one.
Contents of the User-Agent: header from the current request, if
there is one. This is a string denoting the user agent being which
is accessing the page. A typical example is: Mozilla/4.5 [en]
(X11; U; Linux 2.2.9 i586).
Set to a non-empty value if the script was queried through the
HTTPS protocol.
The IP address from which the user is viewing the current page
The Host name from which the user is viewing the current page
The port being used on the user's machine to communicate with
the web server
The absolute pathname of the currently executing script
The value given to the SERVER_ADMIN (for Apache) directive
in the web server configuration file
The port on the server machine being used by the web server for
communication. For default setups, this will be '80';
Contains the current script's path
The URI which was given in order to access this page; for
instance, '/index.html'
When doing HTTP authentication this variable is set to the
username provided by the user
When doing HTTP authentication this variable is set to the
password provided by the user.
Contains any client-provided pathname information trailing the
actual script filename but preceding the query string, if available.
6.6
Database Connectivity with MySQL (using PhpMyAdmin)
MySQL and PHP are two technologies used by many web developers. Connecting to MySQL
from PHP is easy and when we consider that both PHP and MySQL are free technologies, the
pair sounds like winning choice.
MYSQL is open source database. The data in MySQL is stored in database object called
tables. A table is collection of rows and columns. Databases are useful when storing
information categorically. A company may have a database with the following tables
"Employees", "Products", "Customers" and "Orders".
We are going to connect PHP and MySQL with help of PhpMyAdmin, PhpMyAdmin is
nothing but a software which manage MySQL database, tables, how to alter table, add fields,
insert records, backup table and backup database.
phpMyAdmin is an open source php script. Download phpMyAdmin from
www.phpmyadmin.net and unzip it in "htdocs" directory. Or else when you use XAMPP or
WAMPP software for PHP, it also provide us phpMyAdmin also, in that case no need to
install separate phpMyAdmin.
Now we will see how to connect PHP and MySQL, steps will be same for XAMPP or simple
phpMyAdmin
Start your browser and type in the Address
http://localhost/phpMyAdmin/
phpMyAdmin home page displays
Figure 6.12 home page of phpmyadmin
Create new database Student, type name of database and click create button
Figure 6.13 Create database
it will give message that database Student has been created.
Now create new table in database Student.
Figure 6.14 Create table
Table Created named as stud with number of fields 5
Now it will ask you to enter fields information such as field name, datatype, length, default
value etc. Field name will be no, Fname, Mname, Lname, semester.
Figure 6.15 display table field information
Click Save button. Table created
Figure 6.16 Table Successfully created
Here you can edit table fields. Click a pencil icon and change a field name or an attribute. If
you want to delete a field click X icon.
Click Insert link to insert data in the student table. Table fields display for data entry. Enter
your values.
Figure 6.17 insert the fields in table stud
Click Go button. Click Browse link. Inserted records display
Figure 6.16 Table Successfully created
Figure 6.18 Clicking on Browse button view entered data
Click SQL link. SQL text area displays for SQL query.
Edit query
SELECT * FROM `stud` WHERE Fname='Hetal'
And press Go button. Found record displays.
Figure 6.19 SQL Search record displays
So this way database and table is created in phpMyAdmin and now let’s see how to do
coding in php for adding, inserting, deleting and updating records from the database Student.
Connect your Database
Before we can access data in a database, you must create a connection to the database.
In PHP, this is done with the mysql_connect() function.
mysql_connect()
mysql_connect() creates a connection to the database, Returns a MySQL link identifier on
success or FALSE on failure.
Syntax
mysql_connect(servername,username,password);
servername Optional. Specifies the server to connect to. Default value is "localhost"(
localhost is the MySQL server which usually runs on the same physical server
as your script).
username
Optional. Specifies the username to log in with. Default value “root” for
phpmyadmin
password
Optional. Specifies the password to log in with. Default is ""
Example
<?php
$con = mysql_connect("localhost","root","");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
// some code
?>
mysql_close()
The connection will be closed automatically when the script ends. To close the connection
before, use the mysql_close() function. mysql_close return true on success false on failure.
Syntax
bool mysql_close ([ resource $link_identifier ] )
$link_identifier
The MySQL connection. If the link identifier is not specified, the last
link opened by mysql_connect()
Example
<?php
$con = mysql_connect("localhost","root","");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
mysql_close($con);
?>
mysql_select_db()
The mysql_select_db() function sets the active MySQL database. This function returns TRUE
on success, or FALSE on failure.
Syntax
mysql_select_db(database,connection)
database
Required. Specifies the database to select.
connection
Optional. Specifies the MySQL connection. If not specified, the last
connection opened by mysql_connect() is used.
Example
<?php
$con = mysql_connect("localhost", "root", "");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
$db_selected = mysql_select_db("Student", $con);
if (!$db_selected)
{
die ("Can\'t use Student : " . mysql_error());
}
mysql_close($con);
?>
Insert Data into a Database Table
The INSERT INTO statement is used to add new records to a database table.
Syntax
It is possible to write the INSERT INTO statement in two forms.
The first form doesn't specify the column names where the data will be inserted, only their
values
INSERT INTO table_name
VALUES (value1, value2, value3,...)
The second form specifies both the column names and the values to be inserted
INSERT INTO table_name (column1, column2, column3,...)VALUES (value1,
value2, value3,...)
To get PHP to execute the statements above we must use the mysql_query() function. This
function is used to send a query or command to a MySQL connection.
mysql_query()
The mysql_query() function executes a query on a MySQL database. This function returns
the query handle for SELECT queries, TRUE/FALSE for other queries, or FALSE on failure.
Syntax
mysql_query(query,connection)
query
Specify the query to send
connection
Specifies the MySQL connection. If not specified, the last connection opened
by mysql_connect() is used.
Example
<?php
$con = mysql_connect("localhost","root","");
//open connection
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
mysql_select_db("Student", $con); //select database
//insert records in database student and table stud with help of insert query
mysql_query("INSERT INTO stud(no,Fname, Mname, Lname, semester)
VALUES (3, 'Jayna','hardik','Rupani',1)");
//mysql_query() execute the query
mysql_query("INSERT INTO stud(no,Fname, Mname, Lname, semester)
VALUES (4, 'Hetal','Tarun','bhesdadiya',3)");
echo "2 records added";
mysql_close($con);
//close connection
?>
Ouput
echo 2 records added
And now if you wish to see in database open phpmyadmin and select the database student
and table stud
Figure 6.20 Example of insert record through query string
Select Data from a Database Table
The SELECT statement is used to select data from a database
Syntax
SELECT column_name(s)
FROM table_name
To get PHP to execute the statement above we must use the mysql_query() function. This
function is used to send a query or command to a MySQL connection and fetch records from
recordset there are four different way let’s see one by one.




mysql_fetch_array
mysql_fetch_assoc
mysql_fetch_object
mysql_fetch_row
mysql_fetch_array()
The mysql_fetch_array() function returns a row from a recordset as an associative array
and/or a numeric array. This function gets a row from the mysql_query() function and returns
an array on success, or FALSE on failure or when there are no more rows.
After the data is retrieved, this function moves to the next row in the recordset. Each
subsequent call to mysql_fetch_array() returns the next row in the recordset.
Syntax
mysql_fetch_array(data,array_type)
data
array_type
Required. Specifies which data pointer to use. The data pointer is the result
from the mysql_query() function
Optional. Specifies what kind of array to return.
Possible values
•MYSQL_ASSOC - Associative array
•MYSQL_NUM - Numeric array
•MYSQL_BOTH - Default. Both associative and numeric array
Example
<?php
$con = mysql_connect("localhost", "root", "");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
$db_selected = mysql_select_db("Student",$con);
$sql = "SELECT * from stud";
$result = mysql_query($sql,$con);
print_r(mysql_fetch_array($result, MYSQL_BOTH));
mysql_close($con);
?>
Output
Array ( [0] => 1 [no] => 1 [1] => sheetal [Fname] => sheetal [2] => Chandrakant [Mname]
=> Chandrakant [3] => Rakangor [Lname] => Rakangor [4] => 3 [semester] => 3 )
In above example mysql_fetch_array() fetch first record from recordset and print array as
associative array as well as numeric array. Associative array means Fname field name of
table will treat as index of associative array, numeric array index will start from 0. now if
want only numeric array you can write like
print_r(mysql_fetch_array($result, MYSQL_NUM));
same example only this change will return only return numeric array, by default it will return
both numeric as well as associative array.
If user want associative array as output we can make change in above example, it will return
associative array only.
print_r(mysql_fetch_array($result, MYSQL_ASSOC));
mysql_fetch_assco()
The mysql_fetch_assoc() function returns a row from a recordset as an associative array. This
function gets a row from the mysql_query() function and returns an array on success, or
FALSE on failure or when there are no more rows.
After the data is retrieved, this function moves to the next row in the recordset. Each
subsequent call to mysql_fetch_assoc() returns the next row in the recordset.
Syntax
mysql_fetch_assoc(data)
data
Required. Specifies which data pointer to use. The data pointer is the result
from the mysql_query() function
Example
<?php
$con = mysql_connect("localhost", "root", "");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
$db_selected = mysql_select_db("Student",$con);
$sql = "SELECT * from stud";
$result = mysql_query($sql,$con);
print_r(mysql_fetch_assoc($result));
mysql_close($con);
?>
Output
Array ( [no] => 1 [Fname] => sheetal [Mname] => Chandrakant [Lname] => Rakangor
[semester] => 3 )
mysql_fetch_object()
The mysql_fetch_object() function returns a row from a recordset as an object.
This function gets a row from the mysql_query() function and returns an object on success, or
FALSE on failure or when there are no more rows. Each subsequent call to
mysql_fetch_object() returns the next row in the recordset
Syntax
data
mysql_fetch_object(data)
Required. Specifies which data pointer to use. The data pointer is the result
from the mysql_query() function
Example
<?php
$con = mysql_connect("localhost", "root", "");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
$db_selected = mysql_select_db("Student",$con);
$sql = "SELECT * from stud";
$result = mysql_query($sql,$con);
print_r(mysql_fetch_object($result));
mysql_close($con);
?>
Output
stdClass Object ( [no] => 1 [Fname] => sheetal [Mname] => Chandrakant [Lname] =>
Rakangor [semester] => 3 )
mysql_fetch_row()
The mysql_fetch_row() function returns a row from a recordset as a numeric array.
This function gets a row from the mysql_query() function and returns an array on success, or
FALSE on failure or when there are no more rows. After the data is retrieved, this function
moves to the next row in the recordset
Syntax
mysql_fetch_row(data)
data
Required. Specifies which data pointer to use. The data pointer is the result
from the mysql_query() function
Example
<?php
$con = mysql_connect("localhost", "root", "");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
$db_selected = mysql_select_db("Student",$con);
$sql = "SELECT * from stud where Fname='sheetal'";
$result = mysql_query($sql,$con);
print_r(mysql_fetch_row($result));
mysql_close($con);
?>
Output
Array ( [0] => 1 [1] => sheetal [2] => Chandrakant [3] => Rakangor [4] => 3 )
Display result in HTML format
Above example we have seen how we can fetch records from recordset but we were getting
first record or only one record depending on the query we fired, now if we want record in
HTML table format <table> tag is used and while loop is used to access all the records from
the recordset.
Example
<?php
$con = mysql_connect("localhost","root","");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
mysql_select_db("Student", $con);
$result = mysql_query("SELECT * FROM stud");
echo "<table border='1'>
<tr>
<th>no</th>
<th>Fname</th>
<th>Mname</th>
<th>Lname</th>
<th>Semester</th>
</tr>";
while($row = mysql_fetch_array($result)) //fetch one by one record
{
echo "<tr>";
echo "<td>" . $row['no'] . "</td>";
echo "<td>" . $row['Fname'] . "</td>";
echo "<td>" . $row['Mname'] . "</td>";
echo "<td>" . $row['Lname'] . "</td>";
echo "<td>" . $row['semester'] . "</td>";
echo "</tr>";
}
echo "</table>";
mysql_close($con);
?>
Ouput
no
1
2
3
4
Fname
sheetal
Hetal
Jayna
Hetal
Mname
Chandrakant
Navin bhai
hardik
Tarun
Lname Semester
Rakangor 3
Timbadiya 3
Rupani
1
bhesdadiya 3
Update Data In a Database
The UPDATE statement is used to update existing records in a table.
Syntax
UPDATE table_name
SET column1=value, column2=value2,...
WHERE some_column=some_value
Notice the WHERE clause in the UPDATE syntax. The WHERE clause specifies which
record or records that should be updated. If you omit the WHERE clause, all records will be
updated
Example
<?php
$con = mysql_connect("localhost", "root", "");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
$db_selected = mysql_select_db("Student",$con);
$sql=("UPDATE stud SET semester = 4 WHERE Fname = 'Hetal' and Mname='tarun'
");
//Update record where fname=hetal and mname=tarun
$result = mysql_query($sql,$con);
echo ("Number of rows affected" . mysql_affected_rows()."<br>");
//number of rows affected
$sql1="Select * from stud where Mname='tarun' ";
$result = mysql_query($sql1,$con);
print_r(mysql_fetch_row($result));
mysql_close($con);
?>
Output
Number of rows affected1
Array ( [0] => 4 [1] => Hetal [2] => Tarun [3] => bhesdadiya [4] => 4 )
In above example record will update field semester=4 where fname=hetal there are two
records where fname=hetal so mname=tarun is check, mysql_affected_rows() function return
number of rows affected by last query executed.
mysql-affected_rows()
The mysql_affected_rows() function returns the number of affected rows in the previous
MySQL operation. This function returns the number of affected rows on success, or -1 if the
last operation failed
Syntax
mysql_affected_rows(connection)
connection
Optional. Specifies the MySQL connection. If not specified, the last
connection opened by mysql_connect() is used.
Example
<?php
$con = mysql_connect("localhost", "root", "");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
$db_selected = mysql_select_db("Student",$con);
$sql=("UPDATE stud SET semester = 5 WHERE Fname = 'Hetal' ");
$result = mysql_query($sql,$con);
echo ("Number of rows affected" . mysql_affected_rows()."<br>");
mysql_close($con);
?>
Output
Number of rows affected2
In above example we have two records having Fname=’Hetal’ so will change the field
semester =5 in two records and mysql_affected_rows() return 2
Delete Data In a Database
The DELETE FROM statement is used to delete records from a database table.
Syntax
DELETE FROM table_name
WHERE some_column = some_value
Notice the WHERE clause in the DELETE syntax. The WHERE clause specifies which
record or records that should be deleted. If you omit the WHERE clause, all records will be
deleted
Example
<?php
$con = mysql_connect("localhost","root","");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
mysql_select_db("Student", $con);
mysql_query("DELETE FROM stud WHERE Mname='tarun'");
echo ("Number of rows affected " . mysql_affected_rows()."<br>");
mysql_close($con);
?>
Output
Number of rows affected 1
PHP MySQL Function
There are many functions for MySQL using which we can get the database, table’s
information in PHPscript. Let’s see few of them.
mysql_error()
The mysql_error() function returns the error description of the last MySQL operation. This
function returns an empty string ("") if no error occurs.
Syntax
mysql_error(connection)
Connection Optional argument specify the MySql Connection
Example
<?php
$con = mysql_connect("localhost","wrong_user","wrong_pwd");
if (!$con)
{
die(mysql_error());
}
mysql_close($con);
?>
Output
Access denied for user 'wrong_user'@'localhost' (using password: YES)
mysql_errno()
The mysql_errno() function returns the error number of the last MySQL operation. This
function returns 0 (zero) if no error has occurred
Syntax
mysql_errno(connection)
Connection Optional argument specify the MySql Connection
Example
<?php
$con = mysql_connect("localhost","wrong_user","wrong_pwd");
if (!$con)
{
die('Could not connect: ' . mysql_errno()); }
mysql_close($con);
?>
Output
Could not connect: 1045
mysql_data_seek()
The mysql_data_seek() function moves the internal row pointer. The internal row pointer is
the current row position in a result returned by the mysql_query() function. This function
returns TRUE on success, or FALSE on failure.
Syntax
data
row
mysql_data_seek(data,row)
Required. Specifies which data pointer to use.
Required. Specifies which record to move to. 0 indicates the first record
Example
<?php
$con = mysql_connect("localhost", "root", "");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
$db_selected = mysql_select_db("Student",$con);
$sql = "SELECT * from stud ";
$result = mysql_query($sql,$con);
print_r(mysql_fetch_row($result)); //Return first record
mysql_data_seek($result,2);
//move internal pointer to record 3 having index
2
print_r(mysql_fetch_row($result)); // Return third record
mysql_close($con);
?>
Output
Array ( [0] => 2 [1] => Hetal [2] => Navin bhai [3] => Timbadiya [4] => 5 )
Array ( [0] => 4 [1] => Khevna [2] => D [3] => Chhaya [4] => 3 )
mysql_fetch_lengths()
The mysql_fetch_lengths() function returns the length of the contents of each field in a row.
The row is retrieved by mysql_fetch_array(), mysql_fetch_assoc(), mysql_fetch_object(), or
mysql_fetch_row().mysql_fetch_legths() count the number of character enter in the field.
This function returns a numeric array on success, or FALSE on failure or when there are no
more rows.
Syntax
mysql_fetch_lengths(data)
data
Required. Specifies which data pointer to use.
Example
<?php
$con = mysql_connect("localhost", "root", "");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
$db_selected = mysql_select_db("Student",$con);
$sql = "SELECT * from stud WHERE Lname='Chhaya'";
$result = mysql_query($sql,$con);
print_r(mysql_fetch_row($result));
print_r(mysql_fetch_lengths($result));
mysql_close($con);
?>
Output
Array ( [0] => 4 [1] => Khevna [2] => D [3] => Chhaya [4] => 3 ) Array ( [0] => 1 [1] => 6
[2] => 1 [3] => 6 [4] => 1 )
mysql_num_rows()
The mysql_num_rows() function returns the number of rows in a recordset. This function
returns FALSE on failure.
Syntax
mysql_num_rows(data)
data
Required. Specifies which data pointer to use. The data pointer is the result
from the mysql_query() function
Example
<?php
$con = mysql_connect("localhost", "root", "");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
$db_selected = mysql_select_db("Student",$con);
$sql = "SELECT * from stud";
$result = mysql_query($sql,$con);
echo mysql_num_rows($result);
mysql_close($con);
?>
Output
3
There are total three records in database table stud it return 3
Three are certain function which gives information regarding fields of the table let’s see
overview of them. Below is the list of function used for getting information regarding fields
of table
Function
Description
Example
mysql_field_flags() Returns
information $sql = "SELECT * from stud";
regarding flags set, while $result = mysql_query($sql,$con);
creating
table.
like $flags = mysql_field_flags($result, 0);
primary_key
mysql_field_len()
Returns the maximum
length of a field in a
recordset. while creating
table we specify the
length that will return
mysql_field_name() Function returns the
name of a field in a
recordset
echo $flags;
$sql = "SELECT * from stud";
$result = mysql_query($sql,$con);
$len = mysql_field_len($result, 0);
echo $len //25
$sql = "SELECT * from stud";
$result = mysql_query($sql,$con);
$name = mysql_field_name($result,
0);
echo $name //Fname
mysql_fetch_field() Function returns an $sql = "SELECT * from stud";
object
containing $result = mysql_query($sql,$con);
information of a field print_r( mysql_fetch_field($result));
from a recordset.
mysql_field_seek() Jumps to specified fields $sql = "SELECT * from stud";
in a recordset e.g.specify $result = mysql_query($sql,$con);
2 means jump to field mysql_field_seek($result,2);
third
print_r(mysql_fetch_field($result));
mysql_num_fields() function returns the $sql = "SELECT * FROM stud";
number of fields in a $result = mysql_query($sql,$con);
recordset
echo mysql_num_fields($result); //5
eg //no,fname,mname,lname,semester
mysql_field_table() function returns the $sql = "SELECT * from Person";
name of the table where $result = mysql_query($sql,$con);
a specified field is $table = mysql_field_table($result, 0);
located
echo $table;
mysql_field_type() function returns the type $sql = "SELECT * from Person";
of a field in a recordset.
$result = mysql_query($sql,$con);
$type =
mysql_field_type($result,1);//Fname
echo $type; //Return String
Insert, Update, and Delete Data from a Form into a Database
If user wants to insert, update and delete data from a HTML form into a database is possible
and this will be user friendly. Its like mini project, I have created database Student and table
stud with 5 fields no, Fname, Mname, Lname, and semester and created four .php file using
which we can perform operation like add, update, delete and view records in table format. To
view records in table format as well as link’s is given for add, update and delete records in
connection3.php file. so let’s start from connection3.php file.
Example
connection3.php
<html>
<head>
<title> Adding a row to a table</title>
</head>
<body>
<?php
$user = "root";
$pass = "";
$db = "Student";
$link = mysql_connect( "localhost", $user, $pass );
if ( ! $link )
die( "Couldn't connect to MySQL" );
mysql_select_db($db, $link );
$result = mysql_query( "SELECT * FROM stud" );
$num_rows = mysql_num_rows($result);
//Return total number of records in recordset
print "There are currently $num_rows rows in the table<P>";
print "<table border=1>\n";
while ( $a_row = mysql_fetch_row( $result ) )
{
print "<tr>\n";
foreach ( $a_row as $field )
print "\t<td>$field</td>\n";
print "<td><a href='edit.php?Fname=".$a_row[1]."'>Update</a></td>";
print "<td><a href='delete.php?Fname=".$a_row[1]."'>Delete</td>";
print "</tr>\n";
}
print "</table>\n";
print "<a href='add.php'>add a new record</a>\n";
mysql_close( $link );
?>
</body>
</html>
Output
There are currently 3 rows in the table
1 sheetal Chandrakant Rakangor 3 Update Delete
2 Hetal Navin bhai
Timbadiya 5 Update Delete
3 Jayna hardik
Rupani
1 Update Delete
add a new record
Above example will return all records from table stud and added three links like add a new
record, update and delete record.
Now let’s add new record by clicking add a new record it will call add.php file
Example
add.php
<html>
<head></head>
<body>
<?php
$user = "root";
$pass = "";
$db = "Student";
$link = mysql_connect( localhost, $user, $pass );
if ( ! $link )
die( "Couldn't connect to MySQL" );
mysql_select_db($db, $link );
?>
<form method="post">
Roll Number <input type="text" name="no" /><br />
Firstname: <input type="text" name="fn" /><br />
Middlename: <input type="text" name="mn" /><br />
Lastname: <input type="text" name="ln" /><br />
Semester <input type="text" name="sem" /><br />
<input type="submit" value="submit" name="add"/><br />
</form>
<?php
if (isset($_POST['add']))
{
$sql="INSERT INTO stud (no,Fname, Mname,Lname,Semester)
VALUES
('$_POST[no]','$_POST[fn]','$_POST[mn]','$_POST[ln]','$_POST[sem]')";
if (!mysql_query($sql,$link))
{
die('Error: ' . mysql_error());
}
print "<h1>Sucessfully Added ". mysql_affected_rows() ." row</h1><p>";
include("connection3.php");
}
?>
</body>
</html>
Output
Figure 6.21 add records using html form
Once user click submit button it will add record and call connection3.php file it will list out
all the records and give output like this
Figure 6.22 added record in table format
Now let’s update the record by clicking the link Update, it will call edit.php file, which
record you want to update suppose I have selected 1 record Update link then it will call
edit.php?Fname=Sheetal and pass Fname=Sheetal on that bases update query will fired.
Example
edit.php
<?php
$user = "root";
$pass = "";
$db = "Student";
$link = mysql_connect( "localhost", $user, $pass );
if ( ! $link )
die( "Couldn't connect to MySQL" );
mysql_select_db("Student", $link );
$fn=$_REQUEST['Fname'];
$result=mysql_query("select * from stud where Fname='$fn'");
// Split records in $result by table rows and put them in $row.
$row=mysql_fetch_assoc($result);
// Close database connection.
?>
<form method="post">
Roll Number <input type="text" name="no" /><br />
Firstname: <input type="text" name="fn" /><br />
Middlename: <input type="text" name="mn" /><br />
Lastname: <input type="text" name="ln" /><br />
Semester <input type="text" name="sem" /><br />
<input type="submit" value="submit" name="edit"/>
</form>
</body>
</html>
<?php
if (isset($_POST['edit']))
{
$sql="UPDATE stud set
no='$_POST[no]',Fname='$_POST[fn]',Mname='$_POST[mn]',Lname='$_POST[ln]',
semester='$_POST[sem]' where Fname='$fn' ";
if (!mysql_query($sql,$link))
{
die('Error: ' . mysql_error());
}
print "<h1>Sucessfully Updated ". mysql_affected_rows() ." row</h1>";
include("connection3.php");
}
?>
Output
Figure 6.23 example of edit record
edit.php now ask user to update the record where Fname=Sheetal, I have made the changes
and now click submit button it will call connection3.php file it show us the changes made to
it
Figure 6.24 successfully record Updated
Now let’s delete a record when user click on delete link it will Delete the record from the
database and call delete.php file, let’s delete first record it will call
delete.php?Fname=’Sheetal’
Example
delete.php
<?php
$user = "root";
$pass = "";
$db = "Student";
$link = mysql_connect( "localhost", $user, $pass );
if ( ! $link )
die( "Couldn't connect to MySQL" );
mysql_select_db("Student", $link );
$fn=$_REQUEST['Fname'];
// Do delete statement.
$result=mysql_query("delete from stud where Fname='$fn'");
if ( ! $result )
die('Error: ' . mysql_error());
else
echo "Deleted sucessfully <BR>";
// Close database connection
mysql_close();
include("connection3.php");
?>
Output
Deleted sucessfully
There are currently 3 rows in the table
2 Hetal Navin bhai Timbadiya 5 Update Delete
3 Jayna hardik
Rupani
1 Update Delete
4 Khevna D
Chhaya
3 Update Delete
add a new record
This way you can add, update and delete the records using HTML form and table tag.