Laravel - Eloquent - Return Where Related Count Is Greater Than

Working with relational data in Laravel, especially when performing complex aggregations across multiple models, often trips up developers. You want to retrieve a list of parent records (e.g., Brands) based on an aggregated metric from their related child records (e.g., the count of Products). While Eloquent provides powerful tools like whereHas, sometimes the requirements push us toward more direct database interactions.

This post will diagnose why your initial attempts failed and provide robust, idiomatic solutions for finding the top N related models based on a count, ensuring you get fully hydrated Eloquent models back. We’ll explore both the elegant Eloquent approach and the powerful raw query method.

Diagnosing the Initial Attempts

You correctly identified two common strategies, but they hit roadblocks due to how Eloquent's relationship methods interact with complex constraints:

Attempt 1: Using select and groupBy

Product::select('brand', DB::raw('count(brand) as count'))
    ->groupBy('brand')
    ->orderBy('count', 'desc')
    ->take(10)
    ->get();

The Issue: This query successfully generates the aggregated data from the database, but it returns a standard collection of generic objects (or arrays), not full Brand Eloquent models. You are fetching results from the products table context, not the brands table context, which is why you see only Brand and Count, not the full model structure.

Attempt 2: Using whereHas for Filtering

return Brand::whereHas('products', function($q) {
    $q->count() > 10;
})->get();

The Issue: This approach failed with the SQL error (Column not found). This often happens when Eloquent constructs a subquery for whereHas. While it works well for simple existence checks, trying to embed aggregate functions directly into the constraint check can confuse the underlying join logic or cause issues if the relationship setup isn't perfectly aligned in complex scenarios.

The Correct and Thorough Solution: Using Raw Joins

When you need a true "Top N" result based on an aggregated count across related tables, the most performant and reliable method is to leverage explicit SQL joins and grouping directly via the Query Builder or the underlying database facade. This gives you granular control over exactly which models are returned.

We will join brands and products, group by the brand, count the products, order them, and then retrieve the resulting brands.

Implementation with DB Facade

This method ensures we return actual Brand models, fulfilling the requirement perfectly.

use Illuminate\Support\Facades\DB;
use App\Models\Brand; // Assuming Brand model is in App\Models

$topBrands = Brand::query()
    ->select('brands.*', DB::raw('COUNT(products.id) as product_count'))
    ->join('products', 'brands.id', '=', 'products.brand')
    ->groupBy('brands.id') // Group by the primary key of the brand
    ->orderBy('product_count', 'desc')
    ->take(10)
    ->get();

// The $topBrands collection now contains Brand models, each with an added 'product_count' attribute.

Explanation and Best Practices

1. select('brands.*', DB::raw('COUNT(products.id) as product_count')): We select all columns from the brands table (brands.*) and explicitly calculate the aggregate count using DB::raw(). This tells the database exactly what we need: the brand details plus its calculated product count.
2. join('products', 'brands.id', '=', 'products.brand'): We establish the necessary link between the two tables using an explicit JOIN. This is more transparent and often faster than relying solely on Eloquent's implicit relationship loading for complex aggregations.
3. groupBy('brands.id'): Since we are using an aggregate function (COUNT), we must group the results by the non-aggregated columns (in this case, all columns of the Brand). Grouping by the primary key is standard practice.
4. orderBy('product_count', 'desc') and take(10): Standard sorting and limiting to get only the top 10 brands with the most products.

This technique demonstrates that while Eloquent relationships are fantastic for fetching related data, complex aggregations often require stepping down to the Query Builder layer to achieve the optimal performance and structure required. This level of control is key when building high-performance data retrieval systems in Laravel. For deeper insights into optimizing your database queries within the Laravel ecosystem, exploring advanced features shown on laravelcompany.com is highly recommended.

Conclusion

Finding related entities based on aggregated metrics is a common task in application development. When simple filtering fails and you need complex ordering and aggregation across joins, pivot to using explicit database operations via the DB facade. By mastering the combination of join, groupBy, and select with aggregate functions, you gain complete control over your data retrieval, ensuring accuracy and performance. For this specific scenario, the raw query approach provides the most direct path to retrieving fully hydrated Eloquent models based on their associated counts.