查询SQL数据库并创建数组

Question

I am using the below code to pull all the product codes that have a NULL value on ImageURL row

$db = new PDO($dsn, $user, $pass);
$stmt = $db->query('SELECT f.ProductCode FROM Flat_table f WHERE f.ImageURL IS NULL');

$noImageProducts = $stmt->fetchAll(PDO::FETCH_COLUMN, 0);

But the $noImageProducts is empty even if i know that i have Products with no url in the ImageURL field.

Answer 1

there is a difference between empty string and NULL. Try this

 SELECT f.ProductCode FROM Flat_table f WHERE f.ImageURL=''

if this query returns some value that means ImageURL values are not null.