Aggregates (count, sum, avg) in Laravel - Mini Project: Build & Apply

Laravel Aggregates: Count, Sum, and Average

📖 Scenario: You are building a simple Laravel application to manage sales data for a small store. You want to calculate some summary statistics like the total number of sales, the total revenue, and the average sale amount.

🎯 Goal: Build a Laravel Eloquent query that uses aggregate functions count(), sum(), and avg() on a Sale model to get the total sales count, total revenue, and average sale amount.

📋 What You'll Learn

Create a Sale model with a price attribute

Define a variable to hold a minimum price filter

Use Eloquent aggregate methods count(), sum(), and avg() with the filter

Store the results in variables named totalSales, totalRevenue, and averageSale

💡 Why This Matters

🌍 Real World

Stores and businesses often need to calculate total sales, revenue, and average sale amounts to understand performance.

💼 Career

Knowing how to use Laravel collections and aggregate functions is essential for backend developers working with data summaries and reports.

1

Create the Sales Data Array

Create a variable called sales as a collection of arrays with these exact entries: ['price' => 100], ['price' => 200], ['price' => 300], ['price' => 400], ['price' => 500].

Laravel

# Create the sales collection with exact prices
# Your code here

Need a hint?

Use collect([]) to create a Laravel collection with the given arrays inside.

2

Set a Minimum Price Filter

Create a variable called minPrice and set it to 200 to filter sales with price greater or equal to this value.

Laravel

$sales = collect([
    ['price' => 100],
    ['price' => 200],
    ['price' => 300],
    ['price' => 400],
    ['price' => 500],
]);

# Define the minimum price filter
# Your code here

Need a hint?

Just create a variable $minPrice and assign the number 200.

3

Filter Sales and Calculate Aggregates

Use the filter() method on $sales to keep only sales with price greater or equal to $minPrice. Then create variables totalSales with the count of filtered sales, totalRevenue with the sum of price, and averageSale with the average price.

Laravel

$sales = collect([
    ['price' => 100],
    ['price' => 200],
    ['price' => 300],
    ['price' => 400],
    ['price' => 500],
]);

$minPrice = 200;

# Filter sales and calculate totalSales, totalRevenue, averageSale
# Your code here

Need a hint?

Use filter() with a callback to keep sales with price >= $minPrice. Then use count(), sum('price'), and avg('price') on the filtered collection.

4

Return the Aggregates in an Array

Create a variable called summary that is an array with keys 'totalSales', 'totalRevenue', and 'averageSale' set to the respective variables.

Laravel

$sales = collect([
    ['price' => 100],
    ['price' => 200],
    ['price' => 300],
    ['price' => 400],
    ['price' => 500],
]);

$minPrice = 200;

$filteredSales = $sales->filter(fn($sale) => $sale['price'] >= $minPrice);

totalSales = $filteredSales->count();
totalRevenue = $filteredSales->sum('price');
averageSale = $filteredSales->avg('price');

# Create summary array with keys totalSales, totalRevenue, averageSale
# Your code here

Need a hint?

Create an associative array $summary with keys matching the variable names and assign the variables as values.