Select records where not in relational table - laravel

Question

I have 2 tables with this structures :
**table1**
id | title
-----+--------
1 | Blah1
2 | Blah2
**table2**
id | table1_id | article_id
-----+-------------+------------
1 | 1 | 1
2 | 1 | 3
3 | 2 | 1
Now I want to know how can I select all records from table1 where not use in table2
for example I need all table1 records where not exists in table2 for article_id=3
How can I create model and use eloquent models ?
UPDATE:
I need Blah2 from table1 and then show to my user, because Blah1 inserted for article_id = 3 before.
UPDATE 2:
This is worked query, I need write model for this query:
SELECT a.*
FROM table1 AS a
WHERE a.id NOT IN (SELECT table1_id
FROM table2
WHERE article_id = 3
)

Answer 1

you need to create model something like below you can change name appropriately
here i will refer something like below
table1 => ParentModel and table2 => ChildModel
define relation for children in ParentModel with below method
class ParentModel extends Model {
public function children() {
return $this->hasMany(ChildModel::class, 'table1_id');
}
}
whereDoesntHave method is available to filter records with related model
check here https://laravel.com/docs/5.3/eloquent-relationships#querying-relationship-absence
ParentModel::whereDoesntHave('children', function($q){
// here $q refers to related model in this case ChildModel
$q->where('article_id', 3);
})->get();
above query should return the required results.