Returning the first model from a hasMany relationship in Laravel

Question

Is it possible to create a quick method to return the first model from a one-to-many relationship? Here is my code, from the model file:

public function books() {     return $this->hasMany('App\Models\Book'); }  public function first_book() {     return $this->book()->first(); } 

This is the error I'm getting:

Call to undefined method Illuminate\Database\Query\Builder::addEagerConstraints() 

The reason I want to use this is so that I can collect the first record using the with() method, for example:

$authors = Author::with('first_book')->select('*'); 

I'm using these records with Datatables.

Answer 1

I might be late but for your future use and for other who want the same output try this one -

// If you need the last one

public function books() {     return $this->hasOne('App\Models\Book')->latest(); } 

// If you need the first entry -

public function books() {         return $this->hasOne('App\Models\Book')->oldest();     } 

Answer 2

A relation that can be eager loaded has to return a query. The first() function returns an eloquent object.

The solution is to limit the number of results of this query like so:

public function first_book() {     return $this->books()->take(1); } 

$author->first_book will still be a collection, but it will only contain the first related book in your database.