In what scenarios would it be more efficient to use Aggregatfunktionen in SQL instead of manually calculating values in PHP?

Using Aggregatfunktionen in SQL would be more efficient when you need to calculate values based on multiple rows in a database table. Instead of retrieving all the data and then calculating the values manually in PHP, you can simply use SQL Aggregatfunktionen like SUM, AVG, COUNT, etc. to perform the calculations directly in the database query. This can reduce the amount of data transferred between the database and the PHP application, improving performance and reducing the complexity of the code.

// Connect to the database
$pdo = new PDO("mysql:host=localhost;dbname=mydatabase", "username", "password");

// Query to calculate the total sum of a column using SQL Aggregatfunktionen
$sql = "SELECT SUM(column_name) AS total_sum FROM table_name";

// Execute the query
$stmt = $pdo->query($sql);

// Fetch the result
$result = $stmt->fetch(PDO::FETCH_ASSOC);

// Output the total sum
echo "Total Sum: " . $result['total_sum'];