The Battle of With vs Load in Eloquent: Which One Wins?
Tags: php, database, laravel, webdev
Published: 2023-05-02 14:14:56

In the realm of Laravel's Eloquent ORM, developers often find themselves faced with a crucial decision: should they employ the "with" method or the "load" method? These two methods, although similar in purpose, have subtle differences that can significantly impact the performance and behavior of database queries. It's a battle that has intrigued developers for years, as they strive to find the optimal approach for fetching related data in their applications. In this article, we delve deep into the battle of "With vs Load" in Eloquent, aiming to uncover the strengths, weaknesses, and best use cases for each method. So, fasten your seatbelts as we embark on this journey to determine which one emerges as the ultimate winner in the quest for efficient and elegant data retrieval in Laravel.

## Understanding Eloquent relationships?

Eloquent relationships are a fundamental feature of the Laravel framework's Eloquent ORM (Object-Relational Mapping) system. These relationships define the associations between different database tables/entities and enable you to work with related data seamlessly. With Eloquent relationships, you can effortlessly retrieve, manipulate, and perform common database operations on associated records.

By establishing relationships between your database tables, you can create powerful connections that mirror real-world associations, such as one-to-one, one-to-many, and many-to-many relationships. Eloquent provides a fluent and expressive syntax to define and work with these relationships, making it easier to navigate and manipulate your application's data.

Whether you need to fetch a user's posts, retrieve all comments on a blog article, or retrieve a product's categories, Eloquent relationships provide a clean and intuitive way to query and work with related data.

## Exploring `With()` eloquent method.

The `with()` method in Laravel is used to eager load relationships when querying a model. By eager loading relationships, you can retrieve the related models along with the main model in a more efficient way, reducing the number of database queries.

"Eager" refers to the concept of associating related models in a single query instead of using multiple queries. When using eager loading, you fetch the main set of data and also preload the related models associated with that data in a single database query, rather than executing additional queries for each related model.

This approach is beneficial in situations where you have a collection of items and need to access the related models for each item. By eager loading the related models, you can optimize performance by reducing the number of queries required to fetch the associated data.

Without eager loading, you would need to execute a separate query for each item in the initial set to retrieve its related models. This can lead to the "N+1" problem, where the number of queries becomes proportional to the number of items in the set.

Here are some key points to understand about the `with()` method:

- The `with()` method is called on the query builder instance, typically when retrieving models from the database.

- When you use the `with()` method, Laravel will automatically fetch the related models and include them in the query result.

- It uses separate queries to load the related models, based on the relationships defined in your models.

- The related models are then associated with the main model using their defined relationships.

## Unveiling the `load()` Method.

The `load()` method in Laravel is used to load relationships on a model that has already been retrieved from the database. It allows you to load specific relationships dynamically after the initial retrieval.

Here are some key points to understand about the `load()` method:

- The `load()` method is called on an instance of a model.

- When you use the `load()` method, Laravel will fetch the related models and associate them with the main model.

- It uses separate queries to load the related models, similar to eager loading with `with()`, but it applies to an already retrieved model.

- The `load()` method allows you to load relationships on-demand, based on your specific needs.

- It gives you flexibility in choosing which relationships to load, depending on the context of your application.

## The Battle of `with()` vs `load()`:

- Applying Conditions: Both `with()` and `load()` methods in Eloquent allow you to apply conditions to the eager loading of relationships.

With `with()`, you can apply conditions by passing an array of key-value pairs, where the key represents the relationship name and the value represents the conditions to be applied. 

For example:

```
$users = User::with(['posts' => function ($query) {
    $query->where('published', true);
}])->get();

```

In the example above, the `with()` method is used to eager load the posts relationship for the User model, but only load the posts that are published.

Similarly, with `load()`, you can also apply conditions by chaining the where method on the relationship. 

For example:

```
$user = User::find(1);
$user->load(['posts' => function ($query) {
    $query->where('published', true);
}]);

```

In this example, the `load()` method is used to load the posts relationship for a specific user, but only load the published posts.

Both with() and load() methods provide flexibility to apply conditions when eager loading relationships in Laravel's Eloquent ORM.

- Usage Context: The `with()` method in Laravel is used on the query builder instance, typically when retrieving models from the database. When you use the `with()` method, Laravel automatically fetches the related models and includes them in the query result.

On the other hand, the `load()` method is called on an "instance" of a model. With the `load()` method, you can fetch the related models and associate them with the main model. Unlike eager loading, the `load()` method allows you to load relationships on-demand, based on your specific needs. It provides flexibility in choosing which relationships to load, depending on the context of your application.

A key difference between `with()` and `load()` lies in how and when the related models are fetched. With `with()`, the related models are fetched in the initial query, while with `load()`, the related models are fetched separately as needed.

Using the `load()` method can be advantageous when you want to control the loading of relationships dynamically, based on runtime conditions or specific user actions. It allows you to minimize unnecessary queries and optimize performance by loading only the relationships that are necessary in a given context.

- Multiple Relationships: 

`with()`: With `with()`, you can eager load multiple relationships using an array or a comma-separated list of relationship names. This allows you to specify and load multiple relationships efficiently in a single query.
Example:

```
$users = User::with(['posts', 'comments'])->get();
```

`load()`:With load(), you can load multiple relationships individually by calling the `load()` method multiple times on the model instance. This allows you to load specific relationships on a per-instance basis as needed.
Example:

```
$user = User::find(1);
$user->load('posts');
$user->load('comments');
```
- Eager Loading:

`with()`: The `with()` method performs eager loading of relationships, which means it retrieves the related data along with the main query in a single database call. This helps reduce the number of database queries and enhances performance, especially when dealing with large datasets or complex relationships.

`load()`: The `load()` method performs lazy loading of relationships, which means it retrieves the related data on-demand when accessed for the first time. This approach may result in additional database queries if multiple relationships are loaded separately.

## Winner 
In conclusion, the battle of "With vs Load" in Laravel's Eloquent ORM ultimately declares you, the developer building the application, as the ultimate winner. The `with()` method shines when you need to eagerly load relationships during the initial retrieval of models, optimizing performance by reducing queries and eliminating the "N+1" problem. On the other hand, the `load()` method empowers you with the flexibility to load relationships on-demand, allowing you to dynamically fetch related models based on specific runtime conditions or user actions.

The choice between `with()` and `load()` depends entirely on your application's unique requirements and usage context. If you already know in advance which relationships you need to fetch, `with()` becomes an excellent choice for optimizing database queries. However, if you seek greater control over relationship loading based on specific scenarios, the `load()` method proves invaluable, allowing you to fetch related models precisely when needed.

As you harness the power of Laravel's Eloquent ORM, understanding the distinctions and strengths of each method empowers you to make informed decisions, leading to efficient and elegant data retrieval in your Laravel applications. So, embrace your role as the winner and leverage the capabilities of `with()` and `load()` to create exceptional applications that deliver optimal performance and meet your specific needs.