$table->increments('std_id');
            $table->string('std_name', 100)->nullable()->default('');
            $table->string('std_address', 100)->nullable()->default('');
            $table->string('std_tel', 100)->nullable()->default('');
            $table->string('pa_id', 100)->nullable()->default('');
            $table->tinyInteger('c_id')->nullable()->default(null);


public $timestamps = false;
    protected $fillable = ([
        'std_id',
        'std_name',
        'std_address',
        'std_tel',
        'pa_id',
        'c_id'
    ]);