Скачать или смотреть How to Optimize Eloquent Queries with whereHas in Laravel

Discover how to effectively use nested `whereHas` queries in Laravel to filter and retrieve data from related tables. Learn with practical examples!
---
This video is based on the question https://stackoverflow.com/q/69158551/ asked by the user 'L.DZ' ( https://stackoverflow.com/u/11129539/ ) and on the answer https://stackoverflow.com/a/69158756/ provided by the user 'Anthony Aslangul' ( https://stackoverflow.com/u/3330212/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Eloquent query though multiple whereHas

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Optimizing Eloquent Queries with whereHas in Laravel

When working with Laravel and Eloquent ORM, one of the most powerful features is the ability to interact with related models through relationships. However, crafting queries that filter models based on nested relationships can sometimes be tricky. In this guide, we will tackle a common problem: how to perform a query with multiple nested whereHas clauses to retrieve the desired data effectively.

The Problem

Imagine you have a database with a table named Ad. This table has relationships defined with two types of children: Media and time_slot. You want to find specific media records that are associated with an Ad containing a time_slot child that meets certain conditions.

Here’s the context:

Goal: Retrieve media records linked to an Ad with a relevant time_slot.

Condition: The time_slot must fit within the current date and time.

The Solution

You can achieve the desired results by utilizing the whereHas method to define filters on relationships. Let’s break down the solution step-by-step.

Step 1: Setting Up the Query

You begin by preparing the necessary variables. The now() helper in Laravel makes it easy to get the current date and time dynamically:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Constructing the Eloquent Query

Here’s how the refined Eloquent query looks:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the query logic:

with('ad'): Eager load the ad relationship to minimize database queries.

whereHas('ad.time_slot', ...): Nested whereHas enables you to filter based on the conditions set in the time_slot relationship.

whereDate('from', '<=', now()): This condition checks if the from date is less than or equal to the current date.

whereDate('to', '>=', now()): This ensures that the to date is greater than or equal to the current date.

where('format', $frm): Filter the Media records by the specified format.

inRandomOrder(): Randomizes the result set, so you might get a different media each time.

firstOrFail(): Retrieves the first matching result or throws a ModelNotFoundException if no records match.

Step 3: Ensuring Relationships are Correctly Configured

Before executing this query, ensure that:

The relationships (Ad to Media and Ad to time_slot) are correctly defined in your Eloquent models.

The necessary data exists in your database to satisfy the query.

Conclusion

Using the whereHas method effectively allows you to create complex queries that filter through related models easily. The example provided helps demonstrate how you can leverage nested relationships in Laravel to meet specific requirements quickly and efficiently. If you follow the steps outlined above, you should be able to retrieve the data you need with ease!



With this understanding, you can take full advantage of Eloquent's capabilities to manage and query your data effectively in Laravel. Happy coding!