Laravel关系“没有模型”

Question

Short explanation

I have barcode which contains data about inventory shelf. I have multiple shelfs and don't want to create own database record for every shelf place and level. Instead of this, I have records about how many places (aka columns) and levels (aka rows) each shelf contains.

Is it possible to resolve and return this kind of custom model by searching with barcode?

More detailed explanation

I have scannable barcodes attached in every inventory shelf. Barcode contains data about shelf, place and level.

In database, I have model Shelf which have integer attributes "places" and "levels".

In following example I have 3 shelves. Shelf A is the biggest one which have 8 storing places on every 4 levels. Shelf B is a bit smaller and the shelf C is the smallest containing only 2 places and only one level.

| Id | Name | Places | Levels |   
|----|------|--------|--------|
| 1  | A    | 8      | 4      |
| 2  | B    | 5      | 4      |
| 3  | C    | 2      | 1      |

Another model Package belongs to those shelves with pivot. Package can be in shelf A, place 1 and level 2.

{
    id: 1,
    shelf_id: 1,
    receiver_id: 123,
    pivot: {
        place: 1,
        level: 2
    },

    id: 2,
    shelf_id: 1,
    receiver_id: 567,
    pivot: {
        place: 1,
        level: 2
    },

}

Now when I search with barcode data "A-1-2" (barcode data: SHELF-AREA-LEVEL ) I would get packages with ids 1 and 2.

{
    id: 1,
    name: 'A',
    place: 1,
    level: 2,
    packages: [
        {
            id: 1,
            receiver_id: 123,
        },
        {
            id: 2,
            receiver_id: 456,
        }
    ]
}

Is this possible or is it better to do one record for each place?

Answer 1

I think it depends on what further requirements you have on the software. From what I see, you can have multiple packages within a place in a shelf. If you store the number of places and levels within the Shelf model, you assume that all levels and places within that shelf share the same attributes (eg height, width, etc.). If that is indeed the case, I think you can go with your proposed model.

But you are now storing the location of a package in a pivot - this would only make sense if you want to have multiple entries for the same package and shelf, eg if you move the package to another shelf and you want to keep the old information. If you don't need the "location history", you could put the level and place within the Package model instead of in a pivot.

If you want to go full "relational MySQL style", I would create different models for each property. A Package should be in a Place , a Place lies within a Level and a Level belongs to a Shelf , giving you the following structure

Shelf (id, name)
Level (id, shelf_id)
Place (id, level_id)
Package (id, place_id)

That way you could store additional information for each Level / Place. But it depends on your requirements and what your software should be able to accomplish.