How to Specify Specific Columns When Eager Loading Relationship in Laravel

To specify specific columns when eager loading relationship in Laravel you can pass in a closure to the "with" and "load" method and then only "select" the columns that you need for the relationship from within the closure. 

Query Post Model With Specific Column

To only query the "id" and "username" columns of the relationship model, you can write the code below.

<?php

Post::query()
    ->with(['user' => function($query) {
        $query->select(['id', 'username']);
    }])
    ->get();

Using the Load method

If you are using the "load" method then you can write it as follows.

<?php

$post = Post::first();

$post->load(['user' => function($query) {
    $query->select(['id', 'username']);
}]);