[Solved] How can this be witten in Laravel Eloquent term?

EverSQL Database Performance Knowledge Base

How can this be witten in Laravel Eloquent term?

I am converting a piece of database SQL query to Laravel Eloquent query but it doesn't work.

My code snippet looks like this:

SELECT user_id FROM posts WHERE user_id NOT IN (SELECT id FROM users)

Can someone explain why?

How to optimize this SQL query?

The following recommendations will help you in your SQL tuning process.
You'll find 3 sections below:

  1. Description of the steps you can take to speed up the query.
  2. The optimal indexes for this query, which you can copy and create in your database.
  3. An automatically re-written query you can copy and execute in your database.
The optimization process and recommendations:
  1. Create Optimal Indexes (modified query below): The recommended indexes are an integral part of this optimization effort and should be created before testing the execution duration of the optimized query.
  2. Replace In Subquery With Correlated Exists (modified query below): In many cases, an EXISTS subquery with a correlated condition will perform better than a non correlated IN subquery.
Optimal indexes for this query:
ALTER TABLE `users` ADD INDEX `users_idx_id` (`id`);
The optimized query:
SELECT
        posts.user_id 
    FROM
        posts 
    WHERE
        NOT EXISTS (
            SELECT
                1 
            FROM
                users 
            WHERE
                (
                    posts.user_id = users.id
                )
        )

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* original question posted on StackOverflow here.