如何查找field1大于field2的文档? (Nodejs/猫鼬/MongoDB)

在执行查询时如何在比较中使用字段中的值?

How do you use values from fields in comparison when executing queries?

文档示例:

db.inventory.find( { qty: { $gt: 20 } } )

如何使用文档中的字段值而不是20，就像这样:

How can I use a field value from the document instead of 20, like so:

db.inventory.find( { qty: { $gt: field2 } } )

这是我要实现的目标:

var query = model.find();

var first = "field1";
var second = "field2";

query.where(first).gt(second);

我正在动态地构建查询，所以我需要在猫鼬中使用查询生成器.

I am building the query dynamicly, so I need to use the query-builder in mongoose.

Edid2:感谢下面的回答，这就是我解决问题的方法:

Edid2: Thanks to the answer below, this is how I solved my problem:

query.where({$where: "this."+first+" > this."+second});