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1. Chapter-3
PHP DATABASE
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2. Introduction
 PHP supports wide range of relational databases, that
is why it becomes popular. Ex. Microsoft SQL Server,
MySQL, and Oracle etc.
 Advantages of relational database
 Read/write data
 Store more data
 Better organized data
 Faster access to data
 Easier to manipulate
 Relate data to other data
 Here we are going to use MySQL database
 Open source, free, easy to use, popular and good
introduction to DB concepts
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3. Database:
 It is a set of tables. We should have 1 database for 1
application.
 Tables: is a set of rows and columns. It represents a
single concept such as products, customers, orders
etc. We can create relationships among tables.
 Columns: a set of data of single data type. Ex.
FirstName, LastName, Email, Password etc. columns
have types such as strings, integers, float, date etc.
 Rows: single record of data. Ex. “Abebe”, “Kebede”,
“abe@gmail.com”, “password”
 Field: is the intersection of a row and a column. Ex.
FirstName: ”Abebe”
 Index: data structure on a table to increase look up
speed.
 Foreign key: table columns whose values references
rows in another table. The foundation of relational
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4. Basic database operations:
 DDL
 CREATE, DROP, ALTER, RENAME
 DML
 INSERT INTO, UPDATE, DELETE
 QUERY
 SELECT
Connecting to the MySQL Server
 PHP provides us different APIs to deal with databases
 MySQL: Original MySQL API(deprecated @v5.2,
removed @v7)
 Mysqli: MySQL improved API
 PDO: PHP Data Objects
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5.  PHP database APIs
 PHP database interactions in five steps:
 Create a database connection
 Perform Database query
 Use returned data if any
 Release returned data
 Close database connection
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6.  Functions
mysql_connect() or mysqli_connect()
mysql_select_db() or mysqli_select_db()
mysql_query() or mysqli_query()
mysql_fetch_rows() or mysql_fetch_array()
mysqli_fetch_assoc()
mysql_free_results()
mysql_error() or mysqli_error()
mysql_num_rows() or mysqli_affected_rows()
 Connecting to databases
 Before we do anything in MySQL using php, we should
first connect to MySQL server.
 To connect use mysqli_connect(); function
Syntax:
$con=mysqli_connect(“servername”,”dbusername”,
“dbpassword”);
echo “Success fully connected!”
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7.  Creating database:
mysqli_query($con,"create database sims") ;
echo "<br>Database Successfully created";
 Selecting Database
mysqli_select_db($con,”databasename”);
 Creating a table using mysqli
$con= mysqli_connect(“localhost”,”root”,””);
mysqli_select_db($con,“databasename”) ;
mysqli_query($con,"create table feedback
(id int auto_increment,
fname varchar(20),
email varchar(20),
comment LONGTEXT, primary key(id))“
) ;
echo "Feedback table created";
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8.  You can also create table this way
$connection=mysqli_connect(“localhost”,”root”,””,”sims”) ;
$sql=“create table feedback
(id int auto_increment,
fname varchar(20),
email varchar(20),
comment LONGTEXT,primary key(id))“;
if(mysqli_query($connection,$sql))
{
echo "Feedback table created";
}else
{
die(“Table not created:”.mysql_errorr());
}
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9.  Creating table using mysql
$connection=mysqli_connect(“localhost”,”root”,””);
mysqli_select_db(”sims”) ;
$sql=“create table feedback
(id int auto_increment,
fname varchar(20),
email varchar(20),
comment LONGTEXT,primary key(id))“;
if(mysql_query($sql,$connection))
{
echo "Feedback table created";
}else
{
die(“Table not created:”.mysql_errorr());
}
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10.  To insert data into a feed back table using mysql
<?php
$connection=mysqli_connect("localhost","root","");
mysqli_select_db("sims")or die("Database not
selected:".mysql_error());
$sql="insert into feedback(fname,email,comment,date) values
(‘gere',‘gere@gmail.com','Well Done','2017-04-27')";
if(mysqli_query($connection, $sql))
{
echo "Feedback inserted";
}else
{
die(“Failed to insert feedback:".mysql_error());
}
?>
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11. Inserting data using mysqli
<?php
$connection=mysqli_connect("localhost","root","","sims
");
if($connection){
$sql="insert into feedback(fname,email,comment,date)
values (‘gere',‘gere@gmail.com','Well Done','2017-04-
27')";
if(mysqli_query($connection,$sql)){
echo "Feedback inserted";
}else
{ die(“Failed to insert
feedback:".mysqli_error($connection));}
}else{
die(“Connection failed:".mysqli_error($connection));
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12.  To retrieve data from feedback table using mysql
$connection=mysqli_connect("localhost","root","");
mysqli_select_db("sims")or die("Database not selected:".mysql_error());
$sql="select * from feedback order by date desc";
$result=mysqli_query($sql,$connection);
if($result)
{
echo "<table
border=1><tr><th>Name</th><th>Email</th><th>Comment</th></tr>";
while($row=mysqli_fetch_array($result))
{
echo
"<tr><td>".$row['fname']."</td><td>".$row['email']."</td><td>".$row['comment']."<
/d></tr>";
}
echo "</table>";
}else
{
die("Record not found:".mysql_error());
}
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13.  You can retrieve records this way (using mysqli)
$connection=mysqli_connect("localhost","root","","sims");
$sql="select * from feedback order by date desc";
$result=mysqli_query($connection,$sql);
if($result)
{
echo "<table
border=1><tr><th>Name</th><th>Email</th><th>Comment</th></tr>";
while($row=mysqli_fetch_assoc($result))
{
echo
"<tr><td>".$row['fname']."</td><td>".$row['email']."</td><td>".$row['comment']."<
/d></tr>";
}
echo "</tr></table>";
}else
{
die("Record not found:".mysqli_error($connection));
}
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14.  To update data use the same code like insert but you
should change the sql statament
 To delete data retrieve the record you want to delete
using select statement and change the sql statement
Database Security
Sensitive information must be stored in a database in
encrypted format
Encryption in PHP
 Md5($password)
 Sha1($password)
 hash(‘sha1/md5’,$password)
 Crypt($password, $salt)
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15.  SQL Injection
$string=“Insert into feedback values
(‘10’,gere’,’gere@gmail.com’,’Today’s post is
good’,’2017-04-27’)”;
Use escaping string
 Today’s or
 addslashes($string);
 mysqli_real_escape_string($connection,$string)
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