I am trying to create a PHP array of random "fruits" from a database.
The database class that I am using:
class Db
{
private static $_instance = null;
private $_pdo;
private function __construct()
{
try {
$this->_pdo = new PDO('mysql:host=' . DB_HOST . ';dbname=' . DB_NAME .'', DB_USER, DB_PASS);
} catch (PDOException $e) {
die($e->getMessage());
}
}
public static function getInstance()
{
if (!isset(self::$_instance)) {
self::$_instance = new Db();
}
return self::$_instance;
}
public function prepare($sql)
{
return $this->_pdo->prepare($sql);
}
}
The class that is using the database to fetch "fruits" to create an array of a given size of random entries by using 3 seperate queries to calculate and retrieve "x" number of random items form the database.
class FruitBasket
{
private $_fruitArray = array(),
$_inputCode,
$_db;
public function __construct($input = null)
{
$this->_inputCode = $input;
$this->_db = Db::getInstance();
var_dump($this->_db);
}
public function pickFruit($count)
{
$doubleCount = $count * 2;//double the count used in calculation with the random number
$fruitIDs = ''; //the choosen fruits (id's)
$i = 0;
//#1 get total count of fruits table
$sql = "SELECT COUNT(*) FROM `fruits`";
if ($query = $this->_db->prepare($sql)) {
if ($query->execute()) {
$allFruits = $query->fetch(PDO::FETCH_NUM);
} else {
print_r("ERROR QUERY DID NOT EXECUTE #1");
}
} else {
print_r("ERROR CHECK SQL SYNTAX #1");
}
//#2 calculate random number to pull from all of id's
$sql = "SELECT id FROM `fruits` WHERE RAND()* ? < ? ORDER BY RAND() LIMIT 0, ? ";
if ($query = $this->_db->prepare($sql)) {
$query->bindParam(1, $allFruits[0], PDO::PARAM_INT);
$query->bindParam(2, $doubleCount, PDO::PARAM_INT);
$query->bindParam(3, $count, PDO::PARAM_INT);
if ($query->execute()) {
while ($row = $query->fetch(PDO::FETCH_ASSOC)) {
if ($i == 0) {
$fruitIDs .= "'" . $row['id'] . "'";
} else {
$fruitIDs .= ", '" . $row['id'] . "'";
}
$i++;
}
} else {
print_r("ERROR QUERY DID NOT EXECUTE #2");
}
} else {
print_r("ERROR CHECK SQL SYNTAX #2");
}
//#3 get the fruits
$sql="SELECT NAME FROM `fruits` WHERE `id` IN( ? )";
if ($query = $this->_db->prepare($sql)) {
$query->bindParam(1, $fruitIDs, PDO::PARAM_STR);
if ($query->execute()) {
while ($row = $query->fetch(PDO::FETCH_ASSOC)) {
$this->_fruitArray[] = $row['name'];
}
} else {
print_r("ERROR QUERY DID NOT EXECUTE #3");
}
} else {
print_r("ERROR CHECK SQL SYNTAX #3");
}
return $this->_fruitArray;
}
}
The table that I am attempting has a bunch of "fruits" in it, an example of how the table is structured:
==================================
| ID | NAME |
==================================
| 01 | Apple |
==================================
I am attempting to test this all out by using the following:
echo "<pre>";
echo "TESTING FRUIT ARRAY:</br></br>";
$basket = new FruitBasket();
echo"</br></br> PRINT_R: </br></br>";
print_r($basket->pickFruit(10));
echo "</br></br> VARDUMP: </br></br>";
var_dump($basket->pickFruit(10));
The sql query prepares and executes properly, I can do a vardump of the prepares and the binds and they return TRUE. Nothing is returned on the last query however.
In the first query that executes Doing a print statement of $allFruits shows the correct total count from the table.
The second query seems to be working properly,the string $fruitIDs, gets random id's from the table, I can echo this out and confirm that indeed the correct number of ID's are returned.
The problem occurs (I think) with the third query:
Nothing is returned form this query. The prepare statement returns true on a var dump as does the execute, however there is no results!
If I manually take the ID's that are output from query#2 and run it myself in mysql, the correct "fruit" names are returned.
Am I binding the variables incorrectly? I read the pages from the PHP manual but clearly I am doing something wrong.
Please help! :)
