如何通过php / laravel在数据库中保存一个长号码

The following is the method up in my create_users_table migration file

public function up()
{
    Schema::create('users', function (Blueprint $table) {
        $table->increments('id');
        $table->string('first_name');
        $table->string('last_name');
        $table->long('bitcoin_ballance')->default(0.00000000);
        $table->long('lite_ballance')->default(0.00000000);
        $table->string('email')->unique();
        $table->string('user_type')->default('client');
        $table->string('password');
        $table->rememberToken();
        $table->timestamps();
    });
}

I want to save the two $tables with long data types as long numbers(0.00000000), using the long data type gives me the following error

BadMethodCallException : Method Illuminate\Database\Schema\Blueprint::long does not exist.

How do I go about saving a long number in my database, also tried is_long and it throws an error, please help