Php PDO Fetch methods - FETCH_ASSOC,FETCH_NUM,FETCH_BOTH,FETCH_OBJ

Php PDO has fetch methods which are explain as below We generally use mysql database methods for php to retrieve data from database.Like mysql_fetch_assoc ,mysql_fetch_row ,mysql_fetch_array ,mysql_fetch_obj.

 In Php PDO  we have to use different methods to fetch data from database.

Lets consider the connection and we are fetching books from books table

<?php
    // database connection
    $conn = new PDO("mysql:host=$dbhost;dbname=$dbname",$dbuser,$dbpass);
    $sql = "SELECT title FROM books ORDER BY title";
    $query = $conn->query($sql);

 ?> 

PDO fetch method FETCH_ASSOC

Example : 

<?php
    // Fetch using associative array.This method is similar to mysql_fetch_assoc
    $query->setFetchMode(PDO::FETCH_ASSOC);
    while($result = $query->fetch()){
    print_r($result);
}
?>

Result:

Array ( [title] => Book 1)
Array ( [title] => Book 2)

PDO fetch method FETCH_NUM

Example :

 <?php
    // Fetch as numeric array.
    $query->setFetchMode(PDO::FETCH_NUM);
    while($result = $query->fetch()){
    print_r($result);
}
?>

Result:

Array ( [0] => Book 1 )
Array ( [0] => Book 2 )

PDO fetch method FETCH_BOTH

Example : 

<?php
    // Fetch as associative array and numeric array both.This method 
       is similar to mysql_fetch_array 
    $query->setFetchMode(PDO::FETCH_BOTH);
    while($result = $query->fetch()){
    print_r($result);
}
?>

Result:

Array ( [title] => Book 1 [0] => Book 1 )
Array ( [title] => Book 2 [0] => Book 2 )

PDO fetch method FETCH_OBJ

Example :

<?php
    // Fetch as object.This method is similar to mysql_fetch_obj 
    $query->setFetchMode(PDO::FETCH_OBJ);
    while($result = $query->fetch()){
    print_r($result);
}
?>

Result :

stdClass Object
(
[title] =>Book 1
)
stdClass Object
(
[title] =>Book 2
)