javascript - 当对猫鼬返回的结果使用lodash时输出不正确(Incorrect output when using lodash on results returned by mongoose)

Question

I have a result set returned from a mongodb query and am using lodash to reformat it.(我有一个从mongodb查询返回的结果集，并且正在使用lodash重新格式化它。)

I am trying to convert the array of objects into a single object.(我正在尝试将对象数组转换为单个对象。) The problem is when I use lodash on the result set, I get unexpected output.(问题是当我在结果集上使用lodash时，得到了意外的输出。) NOTE: Running the snippet on codepen/codesandbox gives correct output, but not when used directly from mongoose results.(注意：在codepen / codesandbox上运行代码片段将提供正确的输出，但不能直接用于猫鼬结果中。) Mongoose Query(猫鼬查询) try { const petInfo = await pets.find({ userId: user_id, petId: pet_id }) .select({ "_id": 0, "createdAt": 0, "updatedAt": 0, "__v": 0 }); if(!petInfo) { return res.status(400).json({ message: "FAILED_TO_FETCH_PET_INFO" }); } let newObj = _.reduce(petInfo, (acc, cur)=> { return _.assign(acc, cur) }, {}); return res.status(200).json(newObj); } catch (error) { req.errorMsg = error.message; // Log actual error return res.status(500).json({ message: "SOME_ERROR_OCCURRED" }); } Result from mongoose find query (petInfo)(猫鼬查找查询（petInfo）的结果) [ { "age": { "days": "", "months": "", "years": "" }, "userId": "45422605180207851194", "name": "Oscar", "gender": "FEMALE", "type": "Dog", "breed": "", "weight": "", "spayOrNeuter": false, "petId": "KSVv7yJLnUWX3n" } ] Lodash snippet(Lodash片段) let newObj = _.reduce(petInfo, (acc, cur)=> { return _.assign(acc, cur) }, {}); return res.status(200).json(newObj); Result after modification(修改后的结果) { "$__": { "strictMode": true, "selected": { "_id": 0, "createdAt": 0, "updatedAt": 0, "__v": 0 }, "getters": { "age": { "days": "", "months": "", "years": "" } }, "wasPopulated": false, "scope": { "age": { "days": "", "months": "", "years": "" }, "userId": "45422605180207851194", "name": "Oscar", "gender": "FEMALE", "type": "Dog", "breed": "", "weight": "", "spayOrNeuter": false, "petId": "KSVv7yJLnUWX3n" }, "activePaths": { "paths": { "userId": "init", "petId": "init", "name": "init", "gender": "init", "type": "init", "breed": "init", "age.days": "init", "age.months": "init", "age.years": "init", "weight": "init", "spayOrNeuter": "init" }, "states": { "ignore": {}, "default": {}, "init": { "userId": true, "name": true, "gender": true, "type": true, "breed": true, "age.days": true, "age.months": true, "age.years": true, "weight": true, "spayOrNeuter": true, "petId": true }, "modify": {}, "require": {} }, "stateNames": [ "require", "modify", "init", "default", "ignore" ] }, "pathsToScopes": {}, "cachedRequired": {}, "session": null, "$setCalled": {}, "emitter": { "_events": {}, "_eventsCount": 0, "_maxListeners": 0 }, "$options": { "skipId": true, "isNew": false, "willInit": true }, "nestedPath": "age" }, "isNew": false, "_doc": { "age": { "days": "", "months": "", "years": "" }, "userId": "45422605180207851194", "name": "Oscar", "gender": "FEMALE", "type": "Dog", "breed": "", "weight": "", "spayOrNeuter": false, "petId": "KSVv7yJLnUWX3n" }, "$locals": {}, "$init": true }   ask by Ayan translate from so

Answer 1

The reason for this is because mongoose doesn't return the object you think it does.(其原因是因为猫鼬不会返回您认为会返回的对象。)

Instead, it returns a 'mongoose' object with a bunch of methods ect ect.(而是返回带有一系列方法的“猫鼬”对象。) There are 2 ways around this, either call .lean() on your query or toJSON() on the result to sanitize result into normal js object.(有两种解决方法，要么在查询中调用.lean() ，要么在结果上调用toJSON()以将结果清理为普通的js对象。) .lean()(。靠（）) const petInfo = await pets.find({ userId: user_id, petId: pet_id }) .select({ "_id": 0, "createdAt": 0, "updatedAt": 0, "__v": 0 }).lean(); .toJSON()(.toJSON（）) const petInfo = await pets.find({ userId: user_id, petId: pet_id }) .select({ "_id": 0, "createdAt": 0, "updatedAt": 0, "__v": 0 }).lean(); const parsed = petInfo.toJSON()