Group by size category as separate array in laravel php

Question

I have on table size_chart

| id | category | size | created_at          | updated_at | deleted_at |
+----+----------+------+---------------------+------------+------------+
|  1 | Regular  | S    | 2017-10-11 09:35:14 | NULL       | NULL       |
|  2 | Regular  | XS   | 2017-10-11 09:39:34 | NULL       | NULL       |
|  3 | Regular  | M    | 2017-10-11 09:39:37 | NULL       | NULL       |
|  4 | Regular  | xxl  | 2017-10-11 13:03:52 | NULL       | NULL       |
|  5 | Regular  | l    | 2017-10-11 13:03:59 | NULL       | NULL       |
|  6 | Regular  | xm   | 2017-10-11 13:04:03 | NULL       | NULL       |
|  7 | Small    | em   | 2017-10-11 13:05:04 | NULL       | NULL       |
|  8 | standard | em   | 2017-10-13 07:16:50 | NULL       | NULL       |

In this table i have some sample data. I need to group the size based on category For.eg

Regular = [s,xs,M,l,xm]
standard = [em]
small = [em]

How to achieve this on my php controller function

public function sizeFetch(Request $request){
        $cat_id = $request->id;
        $size_id = SizeCategory::where('category_id',$cat_id)->pluck('size_id');
    $size_details = SizeChart::whereIn('id',$size_id)->get();

        return $size_details;
    }

Now this function return like this

[
{
id: 1,
category: "Regular",
size: "S",
created_at: "2017-10-11 09:35:14",
updated_at: null,
deleted_at: null
},
{
id: 2,
category: "Regular",
size: "XS",
created_at: "2017-10-11 09:39:34",
updated_at: null,
deleted_at: null
},
{
id: 3,
category: "Regular",
size: "M",
created_at: "2017-10-11 09:39:37",
updated_at: null,
deleted_at: null
},
{
id: 7,
category: "Small",
size: "em",
created_at: "2017-10-11 13:05:04",
updated_at: null,
deleted_at: null
}
]

Please help me to resolve this

Answer 1

It's probably easier if you do the grouping after you get results. The problem with grouping within the query is that it doesn't really do what you'd expect. (GROUP BY in SQL probably should have been called AGGREGATE BY instead)

public function sizeFetch(Request $request){
    $cat_id = $request->id;
    $size_id = SizeCategory::where('category_id',$cat_id)->pluck('size_id');
    $size_details = SizeChart::whereIn('id',$size_id)
        ->get()->groupBy("category") //Group by category
             ->map(function ($group) {
                   return $group->pluck("size"); //Pluck size from each category member
             });

    return $size_details;
}