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PHP/MySQL tutorial
| Date post: | 12-May-2015 |
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| Upload: | mohamed-ashraf |
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PHP/MySQL tutorial
Introduction
• PHP (Hypertext Preprocessor)- Open source, server-side, scripting language.- Supports databases such as MySQL and Oracle.- http://www.w3schools.com/php/default.asp
• MySQL (Structured Query Language)- Open source, speedy, scalable, reliable database technology. - http://dev.mysql.com/doc/mysql/en/Tutorial.html
Tutorial Overview
Database (MySQL)- DB creation- Add/delete tables- Add/delete/update records- View/query records
Web (PHP)- User front-end- Add & query code- Delete & update code
MySQL & TCD
(1) ‘PuTTY’ into wilde.cs.tcd.ie on port 22 w/ SSH- Authenticate with your TCD username and password
(2) ssh macneil.cs.tcd.ie (password as above)
(3) Login into your MySQL account
‘mysql –uUSERNAME –p’
Enter your MySQL username and password
(4) Use MySQL syntax to create and view table(s), records, etc.
Basic MySQL Syntax
• SHOW DATABASES;
• USE database_name;
• SHOW TABLES;
• DROP TABLE table_name;
Create MySQL Table
CREATE TABLE user (name varchar(9) NOT NULL,
id int(6) NOT NULL,
PRIMARY KEY (id),
UNIQUE (id)
);
Add/Delete/Update Table
• INSERT INTO user VALUES (‘bond’, ‘007’);
• DELETE FROM user WHERE id=‘007’;
• UPDATE user SET name=‘BOND’ WHERE id=‘007’;
Query Database
• SELECT * FROM user;
• SELECT * FROM user WHERE name=‘BOND’;
• SELECT DISTINCT name FROM user;
• SELECT name, id FROM user ORDER BY name;
PHP User Front-End
<html><body> <?php $variable=“271004"; echo $variable; ?></body>
</html>
• Script is executed server side and presented to user via a browser.
• PHP code is rendered as plain HTML.
PHP Configuration File
<?// configuration parameters
// database configuration$host = "macneill.cs.tcd.ie";$user = “username";$pass = “password";$db = “username_db";
// default contact person$def_contact = “Karl";?>
• Use a securely positioned ‘config’ file to store variables.
• Other PHP pages can link to it and use the variables as their own.
PHP Add to DB Code 1
<table cellspacing="5" cellpadding="5"><form action="addUpdate.php" method="POST">
<tr><td valign="top"><b><font size="-1">Title</font></b></td><td><textarea name="title" cols="40" rows="2"></textarea></td></tr>
<tr><td valign="top"><b><font size="-1">Authors</font></b></td><td><textarea name="authors" cols="40" rows="2"></textarea></td></tr>
…
<inut type="Submit" name="submit" value="Add"></td></tr></form></table>
PHP Add to DB Code 2
<?
include("conf.php");
// form submitted so start processing it
$title = $_POST["title"];$authors = $_POST["authors"];…
// set up error list array & validate text input fields$errorList = array();$count = 0;if (!$title) { $errorList[$count] = "Invalid entry: Title"; $count++; }
// set default value for contact personif (!$contact) { $contact = $def_contact; }
// check for errors & if none found...if (sizeof($errorList) == 0)
{
$connection = mysql_connect($host, $user, $pass) or die ("Unable to connect!");
mysql_select_db($db) or die ("Unable to select database!");
$query = "INSERT INTO papers (title, authors, description, comment, super, bibtex, url, genre) VALUES ('$title', '$authors', '$description', '$comment', '$super','$bibtex','$url','$genre')";
$result = mysql_query($query) or die ("Error in query: $query. " . mysql_error());
echo "<font size=-1>Addition successful.<br><br> <a href=papers.php>Go back to the main page</a> | <a href=http://www.cs.tcd.ie/Karl.Quinn/>home</font>";
• // close database connection
mysql_close($connection);}else {// errors occurred}
?>
PHP Query Code
include("conf.php");
$connection = mysql_connect($host, $user, $pass) or die ();mysql_select_db($db) or die ("Unable to select database!");$query = "SELECT * FROM papers";$result = mysql_query($query) or die ("Error in query”);
?><table cellpadding="0" cellspacing="0" border="0" width="622"><tr><td bgcolor="990000"><img src="images/spacer.gif" alt="" height="2"></td></tr><?
// if records present
if (mysql_num_rows($result) > 0){// iterate through resultset & print title with links to edit and delete scripts
while($row = mysql_fetch_object($result)){?><font size="-2"><a href="edit.php?id=<? echo $row->id; ?
>">edit/view</a> | <a href="delete.php?id=<? echo $row->id; ?>">delete</a></font><p>
<font size="-1"><b><? echo $row->title; ?></b><br>
<font size="-1"><b>-<? echo $row->authors; ?></b>
<br><a href="<? echo $row->url; ?>" target="_blank"> pdf</a><br><br><br> </font><table cellpadding="0" cellspacing="0" border="0" width="622"><tr><td bgcolor="990000"><img src="images/spacer.gif" alt="“height="2"></td></tr><?}}
// if no records present else{}
mysql_close($connection);?>
PHP Delete Code
include("conf.php");
// form not yet submitted, display initial form with values pre-filled$id=$_GET['id'];
{// open database connection$connection = mysql_connect($host, $user, $pass) or die ("Unable to connect!");
// select databasemysql_select_db($db) or die ("Unable to select database!");
// generate and execute query$query = "DELETE FROM papers WHERE id = '$id'";$result = mysql_query($query) or die ("Error in query: $query. " . mysql_error());
// close database connectionmysql_close($connection);
// print resultecho "<font size=-1>Deletion successful. <br><br><a href=papers.php>Go back to the main page</a> | <a href=http://www.cs.tcd.ie/Karl.Quinn/>home</font>";}
PHP Update Code 1
$id=$_GET['id'];
if (!$submit){$connection = mysql_connect($host, $user, $pass) or die ("Unable to connect!");mysql_select_db($db) or die ("Unable to select database!");$query = "SELECT title, authors, description, comment, super, bibtex, url, genre FROM papers WHERE id = '$id'";$result = mysql_query($query) or die ("Error in query: $query. " . mysql_error())if (mysql_num_rows($result) > 0){$row = mysql_fetch_object($result);
// print form with values pre-filled?><table cellspacing="5" cellpadding="5">
<form action="Update.php" method="POST"><input type="hidden" name="id" value="<? echo $id; ?>">
<tr><td valign="top"><b><font size="-1">Title</font></b></td><td><textarea name="title" cols="40" rows="2"><? echo $row-
>title; ?></textarea></td></tr>
<tr><td valign="top"><b><font size="-1">Authors</font></b></td><td><textarea name="authors" cols="40" rows="2"><? echo $row >authors; ?></textarea></td></tr>…
<tr><td colspan=2>
<input type="Submit" name="submit" value="Update"></td></tr></form></table>
PHP Update Code 2
include("conf.php");
// form submitted so start processing it$title = $_POST["title"];$authors = $_POST["authors"];…
$id = $_POST["id"];
// set up error list array$errorList = array();$count = 0;
// validate text input fieldsif (!$title) { $errorList[$count] = "Invalid entry: Title"; $count++; }if (!$contact) { $contact = $def_contact; }
// check for errors, if none found...if (sizeof($errorList) == 0)
{$connection = mysql_connect($host, $user, $pass) or die ("Unable to connect!");mysql_select_db($db) or die ("Unable to select database!");
$query = "UPDATE papers SET title = '$title', authors = '$authors', description = '$description', comment = '$comment', super = '$super', bibtex = '$bibtex', url = '$url', genre = '$genre' WHERE id = '$id'";
$result = mysql_query($query) or die ("Error in query: $query. " . mysql_error());// print resultecho "<font size=-1>Update successful.<br><br> <a href=papers.php>Go back to the main page</a> | <a
href=http://www.cs.tcd.ie/Karl.Quinn/>home</a></font>";
// close database connectionmysql_close($connection);}else{}
?>
Summary
• Create MySQL database(s) with tables as required.
• Create PHP powered webpage for adding, deleting, updating and viewing database information.
• Be aware or security concerns vis-à-vis configuration file contents and database info.
