Using MySQLi Extension in PHP

What is MySQLi?
 Since the mid-90s, Mysql extension has served as the
major bridge between PHP and MySQL.
 Although it has performed its duty quite well,
situation has changed since the introduction of PHP 5
and MySQL 4.1
What is MySQLi?
 To correct the issues of MySQL extension, a new
extenstion has been created for PHP5
 It is called MySQLi
 It supports all the latest features in MySQL server 4.1
or higher
 The ‘i’ stands for any one of: improved, interface,
ingenious, incompatible or incomplete.
Major Features
 Procedural Interface
 An object-oriented interface
 Support for the new MySQL binary protocol
that was introduced in MySQL 4.1.
 Support for the full feature set of the MySQL C
client library
Why Make the Switch?
 Maintainable
 Similar Syntax
 New Interface
 Advanced Options
 Speed
 Security
Let’s see the code!
/* Connect to a MySQL Server */
$mysqli = new mysqli('hostname','username','password','database');
if ( mysqli_connect_errno() ) {
echo "Connection error. Errorcode: ".mysqli_connect_error();
/* Close the connection */
How to Run a Query
if ($result = $mysqli->query('SELECT Name, Population FROM City
ORDER BY Population DESC LIMIT 5')) {
/* Fetch the results of the query */
while( $row = $result->fetch_assoc() ){
echo $row['Name'] ." (". $row['Population'] .")\n";
/* Destroy the result set and free the memory used for it */
else {
echo $mysqli->error;
Prepared Statements
 One of the new features of MySQLi
 Using this feature, it is possible to create queries that
 More secure
 Have better performance
 More convenient to write
 Two types of Prepared Statements:
 Bound Parameter
 Bound Result
Bound Parameter Prepared
 A Query template is created and sent to the MySQL
 MySQL server validates it, stores it and returns a
special handle for future use
 When a query needs to be executed, data to fill in the
template is sent to the server
 A complete query is formed and then executed
 The body of the query is sent only once, later only data
to fill in are sent
 Most of the work required to validate and parse the
query only needs to be done a single time, instead of
each time the query is executed.
 The data for the query does not need to be passed
through a function like
to ensure that no SQL injection attacks occur. Instead,
the sent data is handled safely by server when it is
combined with the prepared statement.
Query Structure
 The '?' placeholders can be used in most places
that could have literal data, e.g. a query could be
transformed from
SELECT Population FROM City WHERE Name = 'Dhaka';
SELECT Population FROM City WHERE Name = ?;
 Let’s see a complete example of bound
parameter prepared statement
Using Bound Parameter Prepared
if( $stmt = $mysqli->prepare("INSERT INTO CountryLanguage
VALUES (?, ?, ?, ?)") ){
$stmt->bind_param('sssd', $code, $language,
$official, $percent);
$code = 'BAN';
$language = 'Bangla';
$official = 'F';
$percent = 77.8;
/* execute prepared statement */
$stmt->affected_rows. " Row inserted.\n";
/* close statement and connection */
The Format String
 The following table shows the bound varaible types and
when to use them:
All INT types
All other types
Bound Result Prepared Statements
 Allow the value of variables in a PHP script to be tied
to the value of fields of data in a query result set.
 Create a query
 Prepare the query
 Ask the MySQL server to execute the query
 Bind PHP variables to columns in the query result
 Request that a new row of data be loaded into the
bound variables.
Using Bound Result Prepared
if( $stmt = $mysqli->prepare("SELECT Code, Name FROM
Country ORDER BY Name LIMIT 5") ){
/* bind variables to prepared statement */
$stmt->bind_result($col1, $col2);
/* fetch values */
while ($stmt->fetch()) {
echo $col1 ." ". $col2 ."\n";
/* close statement */
Using Bound Parameters and
Bound Results Together
 It is possible to use bound parameters and bound
results together in a single prepared statement.
 Lets see a more complete example that uses both of
Using Bound Parameters and
Bound Results Together
if ( $stmt = $mysqli->prepare("SELECT Code, Name FROM
Country WHERE Code LIKE ? LIMIT 5") ) {
$stmt->bind_param("s", $code);
$code = "B%";
/* bind variables to prepared statement */
$stmt->bind_result($col1, $col2);
/* fetch values */
while ($stmt->fetch()) {
echo $col1 ." ". $col2 ."\n";
/* close statement */
More Reference
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