Eloquent Query With Custom Method - php

Question

i am using laravel 7 eloquent. i am very new to laravel
this is basic method i am getting data from category table
public function category(){
$category = Category::orderBy('id', 'desc')->get();
$data['pageData'] = $category;
$data['pageTitle'] = "Category";
return view('admin.category.index')->with('data',$data);
}
But i want to do something like this
public function category(){
$category = Category::orderBy('id', 'desc')->get();
if(!empty($_REQUEST['parent_id']))
$category->where('parent_id',$_REQUEST['parent_id']);
$data['pageData'] = $category;
$data['pageTitle'] = "Category";
return view('admin.category.index')->with('data',$data);
}
So how can this is possible using eloquent.
Any help out of this question are helpful for me as i am beginner.

Answer 1

Try this
public function category(){
$query = Category::orderBy('id','desc');
$query = where('parent_id',$_REQUEST['parent_id']);
$category = $query->get();
$data['pageData'] = $category;
$data['pageTitle'] = 'Category';
return view('admin.category.index')->with('data',$data);
}

Answer 2

You can leverage the when() eloquent method to add conditional clause to query:
public function category()
{
$category = Category::when(request('parent_id'),function($parent_id,$query)
{
$query->where('parent_id',$parent_id);
})->orderBy('id', 'desc')->get();
$data['pageData'] = $category;
$data['pageTitle'] = "Category";
return view('admin.category.index')->with('data',$data);
}
when() doc reference https://laravel.com/docs/8.x/queries#conditional-clauses

Answer 3

You can use the when method to only apply the query if the request contains the parent_id.
From the docs:
Sometimes you may want certain query clauses to apply to a query based
on another condition. For instance, you may only want to apply a where
statement if a given input value is present on the incoming HTTP
request. You may accomplish this using the when method:
$role = $request->input('role');
$users = DB::table('users')
->when($role, function ($query, $role) {
return $query->where('role_id', $role);
})
->get();
The when method only executes the given closure when the first
argument is true. If the first argument is false, the closure will not
be executed. So, in the example above, the closure given to the when
method will only be invoked if the role field is present on the
incoming request and evaluates to true.
In your case it would be the following:
use Illuminate\Http\Request;
public function category(Request $request)
{
$categories = Category::query()
->when($request->input('parent_id'), function ($query, $parent_id) {
$query->where('parent_id', $parent_id);
})
->orderBy('id', 'desc')
->get();
$data['pageData'] = $categories;
$data['pageTitle'] = "Category";
return view('admin.category.index')->with('data', $data);
}

Answer 4

You can do as like below
public function category(){
$category = new Category();
if(!empty($_REQUEST['parent_id'])){
$category->where('parent_id',$_REQUEST['parent_id']);
}
$category = $category->orderBy('id', 'desc')->get()
$data['pageData'] = $category;
$data['pageTitle'] = "Category";
return view('admin.category.index')->with('data',$data);
}

Answer 5

Try using laravel when condition
https://laravel.com/docs/8.x/queries#conditional-clauses

Answer 6

Improve your question with proper details. as you mention in the question the second coding path won't work because it doesn't have $request query to functionally run the if statement. anyhow if you want to get only pageData & pageTitle in laravel Eloquent ORM you have to select both columns as follows.
class CategoryController extends Controller
{
public function category(){
$category = Category::select('pageData', 'pageTitle')->orderBy('id', 'desc')->get();
return view('admin.category.index')->with('data', $category);
}
}