How to Use WhereHas In Laravel
Hi readers, I was using WhereHas today in some tasks. So, I decided let's share what it is. If you're building a Laravel application that involves wo...
Hi readers, I was using WhereHas today in some tasks. So, I decided let's share what it is. If you're building a Laravel application that involves working with related models, you'll likely need to perform queries that filter models based on the existence or properties of related models. One of the most powerful and useful methods for performing these kinds of queries is whereHas
. In this post, we'll cover what whereHas
it is, how it works, and some practical examples.
What is WhereHas?
whereHas
is a method available on Laravel's query builder that allows you to filter models based on the existence of related models that match certain conditions? This is especially useful when you want to retrieve models with at least one related model that meets certain criteria.
How does whereHas work?
The whereHas
the method takes two arguments: the name of the relationship method on the current model, and a closure that defines the query to be executed on the related models. Here's an example:
$posts = Post::whereHas('comments', function ($query) {
$query->where('body', 'like', '%important%');
})->get();
In this example, we're retrieving all Post
models that have at least one related Comment
model whose body
the column contains the word "important". Here's how this query works:
- We call the
whereHas
method on thePost
model, passing in the name of thecomments
relationship method as the first argument. - We provide closure as the second argument to
whereHas
, which defines the query to be executed on the relatedComment
models. - Inside the closure, we call the
where
method on the$query
object (which is an instance of Laravel's query builder for theComment
model), filtering theComment
models based on thebody
column.
Note that whereHas
doesn't actually retrieve any related models - it simply filters the main model based on the existence of related models that match the specified conditions.
You can read about Eloquent Relationship Methods On Official Website: Laraveldocs
Practical Examples
Let's look at some practical examples of how to use whereHas
in Laravel.
Example 1: Retrieving Posts with Comments
Suppose you have a Post
the model that has a comments
relationship method is defined as follows:
class Post extends Model
{
public function comments()
{
return $this->hasMany(Comment::class);
}
}
You can use whereHas
to retrieve all Post
models that have at least one related Comment
model:
$posts = Post::whereHas('comments')->get();
In this example, we're not providing closure to whereHas
, which means that we're not filtering the related Comment
models in any way. This query will simply retrieve all Post
models that have at least one related Comment
model.
Example 2: Retrieving Posts with Specific Comments
Suppose you want to retrieve all Post
models that have at least one related Comment
model with the word "important" in its body
column:
$posts = Post::whereHas('comments', function ($query) {
$query->where('body', 'like', '%important%');
})->get();
This query uses a closure to filter the related Comment
models based on their body
columns. We're using the like
operator to perform a case-insensitive search for the word "important" anywhere in the body
column.
Read Also : TIps to optimize your laravel web app
Conclusion
In conclusion, whereHas
is a powerful method in Laravel that allows you to filter models based on the existence or properties of related models. It's useful when you want to retrieve models that have at least one related model that meets certain criteria. I hope this article will help you.