How can PHP developers efficiently calculate and display aggregate values from grouped data without nested database queries?

When working with grouped data in PHP, developers can efficiently calculate and display aggregate values by using the GROUP BY clause in their SQL queries to group the data based on a specific column. Once the data is grouped, developers can use aggregate functions like SUM(), COUNT(), AVG(), etc., to calculate the desired values directly in the SQL query. This approach eliminates the need for nested database queries and allows for a more efficient and streamlined process. 

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

// Query to calculate total sales per product category
$sql = "SELECT category, SUM(sales) AS total_sales FROM products GROUP BY category";

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

// Display the results
while ($row = $stmt->fetch()) {
    echo "Category: " . $row['category'] . " | Total Sales: " . $row['total_sales'] . "<br>";
}

Keywords

PHP aggregate functions grouping data efficient queries data manipulation

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