Strange PDO behavior - php

Question

I'm using the following code:
try {
$this->conn = new PDO("mysql:host=" . DB_HOST . ";dbname=" . DB_NAME, DB_USERNAME, DB_PASSWORD);
$this->conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
catch(PDOException $e)
{
echo $e->getMessage();
}
try {
$stmt = $this->conn->prepare("SELECT id, name FROM images");
if ($stmt->execute()) {
if ($stmt->rowCount() > 0)
return $stmt->fetchAll(PDO::FETCH_ASSOC);
}
else
return NULL;
}
catch(PDOException $e)
{
return $e->getMessage();
}
The code perfectly works, but when I edit my query to:
$stmt = $this->conn->prepare("SELECT id, name, description FROM images");
I obtain an empty result.
Obviously the description field exists. Obviously I tested the new query with PHPMyAdmin.
I found that:
if ($stmt->rowCount() > 0)
is TRUE and I also tried to change the fetclAll to FETCH_BOTH.
Do you have any suggestions?
EDIT: OK, I FOUND THE PROBLEM:
In a record, in the column description there was a "è". If I delete the "è", all is perfectly working. Why this happening?

Answer 1

The Problem was due to an accented letter in a record of the database.
The solution is the use of array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8mb4") to set the character set of the connection to 'UTF-8 MultiByte 4' as follows:
try {
$this->conn = new PDO("mysql:host=" . DB_HOST . ";dbname=" . DB_NAME, DB_USERNAME, DB_PASSWORD, array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8mb4"));
$this->conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
catch(PDOException $e)
{
echo $e->getMessage();
}
The reason this specific version of UTF-8 is used is explained here.