How to display single SQL query results in PHP

Question

I have a query about this php code and cannot display the results in echo, can I convert to string?

//conexion is my function to connect to the database and has been completed


$costTotal=conexion();
$costTotal=$costTotal->query("SELECT SUM(product_cost) FROM product");

echo $costTotal;

For example, the desired result is string(5)"18000"

Answer 1

$costTotal contains the result of the database query, it is not a string, but you are using echo. To output the results as a string, you need to get the data from the query results.

$connection = connexion();

$query = "SELECT SUM(product_cost) as total FROM product";
$result = $connection->query($query);
$data = $result->fetch(PDO::FETCH_ASSOC);

$costTotal = $data['total']; 

echo $costTotal;