PHP MySQL Update query array(0) { } - php

Question

Can anybody help me to understand why my query update dosen't update my data in my database.
This my code php :
<?php
$code = $_GET['code'];
$n1= $_GET['n1'];
$n2= $_GET['n2'];
$n3 = $_GET['n3'];
try {
$connexion= new PDO('mysql:host=localhost;dbname=data','mydata','password');
$sql_update = "UPDATE data.check SET numb_1='".$n1."',numb_2='".$n2."','numb_3'='".n3."' WHERE 'code_product' =".$code;
$query = $connexion-> prepare($sql_update);
$query -> execute();
$data_update= $query -> fetchAll(PDO::FETCH_ASSOC);
}
catch(PDOException $e)
{
echo "<br>" . $e->getMessage();
}
Thanks for any help.

Answer 1

1) Change
$sql_update = "UPDATE data.check SET numb_1='" . $n1 . "',numb_2='" . $n2 . "','numb_3'='" . n3 . "' WHERE 'code_product' =" . $code;
To
$sql_update = "UPDATE data.check SET numb_1='" . $n1 . "',numb_2='" . $n2 . "','numb_3'='" . $n3 . "' WHERE `code_product` =" . $code;
=> In n3 you forgot to add $. And, replace single quotes with backtick to enclose column name.
Updated Code
<?php
$code = $_GET['code'];
$n1 = $_GET['n1'];
$n2 = $_GET['n2'];
$n3 = $_GET['n3'];
try {
$connexion = new PDO('mysql:host=localhost;dbname=data', 'mydata', 'password');
$sql_update = $connexion->prepare("UPDATE `data`.`check` SET numb_1 = :numb_1 , numb_2 = :numb_2, numb_3 = :numb_3 WHERE `code_product` = :code_product");
$sql_update->execute(array(':numb_1' => $n1,':numb_2'=>$n2, ':numb_3'=>$n3,':code_product'=>$code));
$stmt = $connexion->prepare("SELECT * FROM `data`.`check` WHERE code_product=:code_product");
$stmt->execute(array(':code_product'=>$code));
$data_update= $stmt -> fetchAll(PDO::FETCH_ASSOC);
} catch (PDOException $e) {
echo "<br>" . $e->getMessage();
}
?>

Answer 2

After your update execution you need to query again for fetching result like,
$sql_update = "UPDATE data.check SET numb_1='".$n1."',numb_2='".$n2."','numb_3'='".$n3."' WHERE 'code_product' =".$code;
$query = $connexion-> prepare($sql_update);
$query -> execute();
$query = $dbh->prepare("SELECT * FROM data.check");
$query->execute();
$data_update= $query -> fetchAll(PDO::FETCH_ASSOC);// now it will get records