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PHP TUTORIAL PHP and Database
| Date post: | 07-Jul-2015 |
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PHP TUTORIAL
PHP and Database
What is Database?
● A database is an organized collection of data.
● The data collection are typically organized to model relevant aspects of reality in a way that supports processes requiring this information
What is Database Management System?
● Database management systems (DBMSs) are specially designed applications that interact with the user, other applications, and the database itself to capture and analyze data.
● A general-purpose database management system (DBMS) is a software system designed to allow the definition, creation, querying, update, and administration of databases.
Why use database?
● Databases are most useful when it comes to storing information that fits into logical categories.
● Example: store employees record– Supervisors table, managers tables, suppliers
table, etc.
Why MySQL?
● The most popular database system used with PHP.● PHP combined with MySQL are cross-platform (you
can develop in Windows and serve on a Unix platform)● Most web hosts do not allow you to create a database
directly through a PHP script.● Instead they require that you use the PHP/MySQL
administration tools on the web host control panel to create these databases
What is “Queries”
● A query is a question or a request.● We can query a database for specific
information and have a recordset returned● Example:
– SELECT * FROM customers;
How to learn SQL
● Remember this:– SQL language is not complicated
● There are many keywords in MySQL, and a good programming habit when using ANY of these words is to capitalize them.
● This helps draw them out from the rest of the code and makes them much easier to read.
● Example:– SELECT * FROM example
SQL Basic Command
● Create Database– CREATE DATABASE <database_name>
● Use Database– Use <database_name>
● Create Table– CREATE TABLE <table_name> (col1 type1, col2 type2, … , colx
typex)
● Example– CREATE DATABASE exercise;
– Use exercise;
– CREATE TABLE student (name varchar(30), age INT);
SQL Basic Command
● Insert data to table– INSERT INTO <table_name> (col1,col2, … , colx)
VALUES (val1, val2, … , valx);
– Example:● INSERT INTO student VALUES ('William',27);
● Query data from table– SELECT <colx| *> FROM <table_name> WHERE
<expression>
– Example:● SELECT name FROM student WHERE age>20;
SQL Basic Command
● Edit data– UPDATE <table_name> SET <colx=valx> WHERE
<expression>
● Delete data– DELETE FROM <table_name> WHERE <expression>
● Example– UPDATE student SET age=30 WHERE
name='William';
– DELETE FROM student WHERE name='William';
PHP Form Handling
● Use $_GET or $_POST to handle the data from the form● Example (form_get.html)
<html>
<body>
<form action="helloget.php" method="get">
Name: <input type="text" name="name"><br>
<input type="submit">
</form>
</body>
</html>
PHP Form Handling
● Helloget.php
<html>
<body>
Welcome <?php echo $_GET["name"]; ?>
</body>
</html>
PHP Form Handling
● (form_post.html)
<html>
<body>
<form action="hellopost.php" method="post">
Name: <input type="text" name="name"><br>
<input type="submit">
</form>
</body>
</html>
PHP Form Handling
● Hellopost.php
<html>
<body>
Welcome <?php echo $_POST["name"]; ?>
</body>
</html>
PHP Form Handling
● GET vs. POST– $_GET is an array of variables passed to the
current script via the URL parameters.
– $_POST is an array of variables passed to the current script via the HTTP POST method.
PHP Form Handling
● When we use GET method?– Remember this : Information sent from a form
with the GET method is visible to everyone (in address bar).
– GET has limits on the amount of information to send (only 2000 character).
– ONLY USED for sending non-sensitive data.
– Never use GET to send sensitive informations such as username or password
PHP Form Handling
● When we use POST method?– Remember this : Information sent from a form
with the POST method is invisible to others.
– POST has no limits on the amount of information to send.
– Supports advanced functionality such as multi-part binary input while uploading files to server.
PHP & MySQL
● Open connection to MySQL– mysqli_connect(host, username, password,
database_name)
– Example
$con=mysqli_connect(“localhost”,”root”,”1234”,”exercise”);
● Check connection
if (mysqli_connect_errno($con))
echo "Failed to connect to MySQL: " . mysqli_connect_error();
PHP and MySQL
● Close connection– mysqli_close(connection_variable)
● Example– mysqli_close($con);
PHP and MySQL
● Send query to MySQL– mysqli_query(<query>,<connection_variable>
);
● Example:
$sql=”INSERT INTO student VALUES('John',33)”;
mysqli_query($sql,$con);
PHP and MySQL
● Retrieve result of query
$sql=”SELECT * FROM student”;
$result=mysqli_query($sql,$con);
While ($row = mysqli_fetch_array($result)) {
echo $row['name'] . “ “ . $row['age'] . “<br>”;
}
excercise
● A. Database– Use database exercise
– Create a course table which have structure like this:● id_course – varchar● name_course – varchar● Credit – int
– Create a student table which have structure like this:● id_student – varchar● Firstname – varchar● Lastname - varchar
– Insert 10 data into table course and student
excercise
● B. PHP and MySQL– Create a web application with php to handles
● The input for table course and student● List all data for table course and student● Search data for table course and student
Home Works
● Create a web applications with PHP to handle the update and delete proses for table course and student
