How do I loop through a MySQL query via PDO in PHP?

Question

I'm slowly moving all of my LAMP websites from mysql_ functions to PDO functions and I've hit my first brick wall. I don't know how to loop through results with a parameter. I am fine with the following:

foreach ($database->query("SELECT * FROM widgets") as $results)
{
   echo $results["widget_name"];
}

However if I want to do something like this:

foreach ($database->query("SELECT * FROM widgets WHERE something='something else'") as $results)
{
   echo $results["widget_name"];
}

Obviously the 'something else' will be dynamic.

Answer 1

Here is an example for using PDO to connect to a DB, to tell it to throw Exceptions instead of php errors (will help with your debugging), and using parameterised statements instead of substituting dynamic values into the query yourself (highly recommended):

// connect to PDO
$pdo = new PDO("mysql:host=localhost;dbname=test", "user", "password");

// the following tells PDO we want it to throw Exceptions for every error.
// this is far more useful than the default mode of throwing php errors
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

// prepare the statement. the placeholders allow PDO to handle substituting
// the values, which also prevents SQL injection
$stmt = $pdo->prepare("SELECT * FROM product WHERE productTypeId=:productTypeId AND brand=:brand");

// bind the parameters
$stmt->bindValue(":productTypeId", 6);
$stmt->bindValue(":brand", "Slurm");

// initialise an array for the results
$products = array();
$stmt->execute();
while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
    $products[] = $row;
}