php - How to use DB::raw in eager loading

Question

I'm currently using eager loading in laravel and used the select() method. However, when I tried to select the child table, it returns an error. Please see my code below.

Controller

$posts = Post::with('author');

$posts->select(['body', DB::raw('CONCAT(users.first_name, " ", users.last_name) as AUTHOR')]);

The code above returns this error:

Column not found: 1054 Unknown column 'users.first_name' in 'field list'

So I tried to make it like this:

$posts = Post::with('author');

$posts->select(['body', DB::raw('CONCAT(author.first_name, " ", author.last_name) as AUTHOR')]);

Now I used the relationship to get the first and last name but I'm getting the same error. Any idea?

UPDATE

I'm using laravel 5.2 for this project.

Answer 1

You should be able to tackle this with:

$posts = Post::with('author:id,first_name,last_name')->get();

Based on laravel docs you have to provide the column names of the relationship table as above. Don't forget to Add the "id" as well because it will not work otherwise.