Laravel - Add column to existing pivot table and add MUL key

Question

I have a Laravel pivot table which contains multiple primary keys: "order_id", "product_id", "variation_id".

I need to add a new column called "id" to this table which I do as follows:

public function up()
    {
        Schema::table('order_product', function (Blueprint $table) 
        {
            $table->integer('id')->unsigned()->after('variation_sku');
        });
    }

My original migration file looks as follows:

public function up()
    {
        Schema::create('order_product', function (Blueprint $table) 
        {
            $table->integer('order_id')->unsigned()->index();
            $table->foreign('order_id')->references('order_id')->on('orders')->onDelete('cascade');
            $table->integer('product_id')->unsigned()->index();
            $table->foreign('product_id')->references('product_id')->on('products')->onDelete('cascade');
            $table->integer('variation_id')->unsigned()->index()->nullable();
            $table->jsonb('variation')->nullable();
            $table->integer('qty');
            $table->string('variation_status')->default('bakery');
            $table->timestamps();
            $table->softDeletes();
            $table->primary(['order_id', 'product_id', 'variation_id']);
        });
    }

This migration includes my 3 composite keys.

I now need to add the new column "id" and add this column to the composite keys.

I cannot find anything in the Laravel documentation and have a suspicion that this may not be possible as it may affect past records in this table.

Answer 1

You could drop the primary key then create a new one:

public function up()
{
    Schema::table('order_product', function (Blueprint $table) 
    {
        $table->integer('id')->unsigned()->after('variation_sku');
        $table->dropPrimary();
        $table->primary(['id', 'order_id', 'product_id', 'variation_id']);
    });
}