按 Laravel 5.3 中两列的差值排序

Order by the difference of two columns in Laravel 5.3

我有一个 eloquent 查询，其中 orderBy 之一是两列的差异。

$mymodel = Level::where([['ColA', 5], ['ColB', 10], ['ColC', 7]])
                 ->orderBy('ColA', 'Desc')
                 ->orderBy('ColA' - 'ColB', 'Desc')
                 ->orderBy('ColC', 'Desc')
                 ->orderBy('ColD', 'Asc')
                 ->pluck('userId')->toArray();

使用 sqlite 在 localhost 上使用完全相同的代码可以正常工作。但是在 MySQL 的生产中有以下错误

SQLSTATE[42S22]: Column not found: 1054 Unknown column '0' in 'order clause' (SQL: select `userId` from `levels` where (`ColA` = 5 and `ColB` = 10 and `ColC` = 7) order by `ColA` desc, `0` desc, `ColC` desc, `ColD` asc)

$model = Level::where($wheres)
              ->orderByRaw('(ColA - ColB) DESC')
              ->pluck('userId')
              ->toArray();