Laravel Drop Foreign Column

2016_05_14_172105_CreateSomeRelation.php

<?php

use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Schema\Builder;
use Illuminate\Database\Migrations\Migration;

class CreateSomeRelation extends Migration
{
    /**
     * @var Builder
     */
    protected $schema;

    public function __construct()
    {
        $this->schema = get_schema();
    }
    
    public function up()
    {
        $this->schema->table('some_table', function (Blueprint $table) {
            $table->integer('some_col')->unsigned();
            $table->foreign('some_col')->references('id')->on('some_table');
        });
    }
    
    public function down()
    {
        $this->schema->table('some_table', function (Blueprint $table) {
            $table->dropForeignColumn('some_col');
            
            // vs.
            // $table->dropForeign('some_table_some_col_foreign');
            // $table->dropColumn('some_col');
        });
    }
}

app.php

<?php

// Place the following in bootstrap/app.php before return $app;
use App\Support\Database\Blueprint;
use App\Support\Database\MySqlGrammar;
use Illuminate\Database\Schema\Builder;

/**
 * @return Builder
 */
function get_schema()
{
    DB::setSchemaGrammar(new MySqlGrammar());

    $schema = DB::getSchemaBuilder();
    $schema->blueprintResolver(function ($table, $callback) {
        return new Blueprint($table, $callback);
    });

    return $schema;
}

Blueprint.php

<?php

namespace App\Support\Database;

class Blueprint extends \Illuminate\Database\Schema\Blueprint
{
    public function dropForeignColumn($column)
    {
        $this->dropForeign($this->table.'_'.$column.'_foreign');
        $this->dropColumn($column);
    }
}