laravel用外键填充选择框

Question

There are 3 tables

Sizes
id
name

Products
id
name

Product_sizes
id
product_id
size_id

I want to fill an selectbox with the id of product_sizes and the name of the foreign key connected table size.

for exampe:

product_sizes.id    1
sizes.name          medium

where medium would be found by size_id in product sizes. How can I the name value in the list?

What i currently have

I can get the right row with

 $sizes =  $product->sizeAvailable()->lists('pr', 'size_id');

where sizeAvailable is a relation that returns all product_sizes for a selected product.

Answer 1

First of all you don't need an id field in the pivot table because you can uniquely identify each row with the composite key product_id, size_id. A Product can belong to many Sizes and a Size can belong to many Products, thus you shouldn't have duplicate rows.

The relationships of each model are like the following:

class Product extends Model {
    public function sizeAvailable() {
        return $this->belongToMany('Size', 'product_sizes');
    }
}

class Size extends Model {
    public function products() {
        return $this->belongToMany('Product', 'product_sizes');
    }
}

Finally in your View you can use Blade functions to generate your selectbox:

<select>
    @foreach($product->sizeAvailable() as $size)
        <option value="{{ $size->id }}">{{ $size->name }}</option>
    @endforeach
</select>