javascript - 如何删除 Mongoose 模式中的引用值

Question

const UniversitySchema = new Schema({
	university_name: {
		type:String,
		
	},
	status: {
		type: String
	}

});

const CollageSchema = new Schema({
	collage_name: {
		type:String,
		required: [true,'Name field is required']
	},
	university_id: {
		type: [{ type: Schema.Types.ObjectId ,
		ref: 'university' }]

	},
	type: {
		type:String
	}

});

router.delete('/university/:id',function(req,res,next){
	University.findByIdAndRemove({_id:req.params.id}).then(function(detail){
		res.send(detail);
	});
});

我在 CollageSchema 中引用了 UniversitySchema 的 _id，如果我删除任何大学，相应的拼贴画也应该被删除。这个怎么做？

Answer 1

通过对 collages 集合的额外 mongo 调用，使用 Promise.all() :

router.delete('/university/:id',function(req,res,next){

    const ObjectId = require('mongodb').ObjectId;
    const _id = ObjectId(req.params.id);

    const removeUniversity = University.findByIdAndRemove({ _id: _id });
    const removeCollage    = Collage.remove({ university_id: _id });

    Promise
        .all([removeUniversity, removeCollage])
        .then(function(values) {
            const detail = values[0];
            res.send(detail);  
        })
        .catch((err) => console.error(err));

});