所以我在 router.js 文件中得到了这串链式函数，它应该传递一些查询的结果。不幸的是，当我从最后一个链接函数传递数组时，它只传递最后一个元素 secondDoc。具体在这个地方:
return {
Artwork: firstDoc,
Support: secondDoc
}
}
}).then( (doc) => {
代码如下:
路由器.js:
var express = require('express');
var router = express.Router();
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost:27017/3DArtistsForum');
var ObjectId = mongoose.Types.ObjectId;
var verbose = 2;
var setup = false;
var models = require('../models');
/* GET home page. */
router.get('/', function(req, res, next) {
models.forums.find({}).then( function (doc) {
return doc;
}).then( function(doc) {
var id = doc[0]._id;
var id_2 = doc[1]._id;
var id_3 = doc[2]._id;
models.subforums.find({parentID: id}, function(err, firstDoc) {
if (err) {
console.log(err);
} else {
// console.log(firstDoc);
return firstDoc;
}
}).then( firstDoc => {
models.subforums.find({parentID: id_2}, function(err, secondDoc) {
if (err) {
console.log(err);
} else {
var docArray = {
Artwork: firstDoc,
Support: secondDoc
}
if (verbose >= 2) {
console.log('before passing: \n');
console.log(docArray);
}
return docArray;
}
}).then( (doc) => {
models.subforums.find({parentID: id_3}, function(err, thirdDoc) {
if (err) {
console.log(err);
} else {
if (verbose >= 2) {
console.log('after passsing: \n');
console.log(doc);
}
if ('Artwork' in doc) {
console.log('\'Artwork\' exists!');
} else {
console.log('\'Artwork\' does not exist!');
}
if ('Support' in doc) {
console.log('\'Support\' exists!');
} else {
console.log('\'Support\' does not exist!');
}
var subforumsDoc = {
Artwork: doc.Artwork,
Support: doc.Support,
Coding: thirdDoc
}
if (verbose >= 2) {
console.log('\nsubforumDoc: \n');
console.log(subforumsDoc);
}
res.render('index', { title: '3D Artist Forum', forums: subforumsDoc});
}
});
})
});
})
});
router.get('/subforum/:forumIndex/:subforumIndex', function (req, res, next) {
var forumIndex = req.params.forumIndex;
var subforumIndex = req.params.subforumIndex;
models.forums.find({}).then( function (forumDoc) {
return forumDoc;
}).then( forumDoc => {
models.subforums.find({}).then( function (subforumDoc) {
var forumName = forumDoc[forumIndex].name;
var subforumName = subforumDoc[subforumIndex].name;
if (verbose >= 1) {
console.log("forumName: " + forumName);
console.log("subforumName: " + subforumName);
}
res.render('subforum', {title: subforumName});
});
})
})
module.exports = router;
我使用 Mongoose 从 MongoDB 数据库中提取数据，该函数的输出如下:
before passing:
{ Artwork:
[ { _id: 5bf9e49c132cfe4e1c3edde2,
name: 'Forum Gallery',
date: 2018-11-24T23:54:04.632Z,
description: 'Your best artworks',
parentID: 5bf9e49c132cfe4e1c3edddb,
forumIndex: 0,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3edde6,
name: 'Focused Critiques',
date: 2018-11-24T23:54:04.633Z,
description: 'Where you can get focused critiques',
parentID: 5bf9e49c132cfe4e1c3edddb,
forumIndex: 0,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3edde8,
name: 'Sketchbooks',
date: 2018-11-24T23:54:04.633Z,
description: 'A place to put your personal sketchbooks',
parentID: 5bf9e49c132cfe4e1c3edddb,
forumIndex: 0,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3edde4,
name: 'Finished Projects',
date: 2018-11-24T23:54:04.633Z,
description: 'All your finished projects',
parentID: 5bf9e49c132cfe4e1c3edddb,
forumIndex: 0,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddea,
name: 'Animations',
date: 2018-11-24T23:54:04.634Z,
description: 'All your animation projects',
parentID: 5bf9e49c132cfe4e1c3edddb,
forumIndex: 0,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddec,
name: 'Blender Tests',
date: 2018-11-24T23:54:04.634Z,
description: 'All your experiments and tests',
parentID: 5bf9e49c132cfe4e1c3edddb,
forumIndex: 0,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddee,
name: 'Traditional',
date: 2018-11-24T23:54:04.634Z,
description: 'Traditional mediums such as pencil and paper',
parentID: 5bf9e49c132cfe4e1c3edddb,
forumIndex: 0,
__v: 0 } ],
Support:
[ { _id: 5bf9e49c132cfe4e1c3eddf0,
name: 'Tutorials, Tips and Tricks',
date: 2018-11-24T23:54:04.634Z,
description: 'Tutorials, tips and tricks',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddf2,
name: 'Basics and Interface',
date: 2018-11-24T23:54:04.634Z,
description: 'Q&A for newbies',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddf4,
name: 'Modeling',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A about modeling',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddf6,
name: 'Materials and Textures',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A about materials and texturing',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddf8,
name: 'Particles and Physics Simulations',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A about particles and physics simulations',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddfa,
name: 'Lighting and Rendering',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A about lighting and rendering',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddfe,
name: 'Compositing and Post Processing',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A about compositing and post processing',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3ede00,
name: 'Technical Support',
date: 2018-11-24T23:54:04.635Z,
description:
'Q&A related to hardware, drivers, and your favorite 3D program',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3ede02,
name: '3D Artists Forum Support',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A related to this forum',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddfc,
name: 'Animation and Rigging',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A about animation and rigging',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 } ] }
after passsing:
[ { _id: 5bf9e49c132cfe4e1c3eddf0,
name: 'Tutorials, Tips and Tricks',
date: 2018-11-24T23:54:04.634Z,
description: 'Tutorials, tips and tricks',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddf2,
name: 'Basics and Interface',
date: 2018-11-24T23:54:04.634Z,
description: 'Q&A for newbies',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddf4,
name: 'Modeling',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A about modeling',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddf6,
name: 'Materials and Textures',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A about materials and texturing',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddf8,
name: 'Particles and Physics Simulations',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A about particles and physics simulations',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddfa,
name: 'Lighting and Rendering',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A about lighting and rendering',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddfe,
name: 'Compositing and Post Processing',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A about compositing and post processing',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3ede00,
name: 'Technical Support',
date: 2018-11-24T23:54:04.635Z,
description:
'Q&A related to hardware, drivers, and your favorite 3D program',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3ede02,
name: '3D Artists Forum Support',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A related to this forum',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 },
{ _id: 5bf9e49c132cfe4e1c3eddfc,
name: 'Animation and Rigging',
date: 2018-11-24T23:54:04.635Z,
description: 'Q&A about animation and rigging',
parentID: 5bf9e49c132cfe4e1c3edddc,
forumIndex: 1,
__v: 0 } ]
'Artwork' does not exist!
'Support' does not exist!
subforumDoc:
{ Artwork: undefined,
Support: undefined,
Coding:
[ { _id: 5bf9e49c132cfe4e1c3ede04,
name: 'Released Scripts and Themes',
date: 2018-11-24T23:54:04.635Z,
description: 'Scripts, addons, & themes',
parentID: 5bf9e49c132cfe4e1c3edddd,
forumIndex: 2,
__v: 0 } ] }
我错过了什么愚蠢的东西吗？如何将firstDoc和secondDoc传递到下一个.then()调用中？
最佳答案
router.get('/', async (req, res, next) => {
try{
let doc = await models.forums.find({}).lean();
let firstDoc = await models.subforums.find({parentID: doc[0]._id }).lean();
let secondDoc = await models.subforums.find({parentID: doc[1]._id }).lean();
let thirdDoc = await models.subforums.find({parentID: doc[1]._id }).lean();
var docArray = { Artwork: firstDoc, Support: secondDoc }
if (verbose >= 2) {
console.log('before passing: \n');
console.log(docArray);
}
if (verbose >= 2) {
console.log('after passsing: \n');
console.log(doc);
}
if ('Artwork' in doc) {
console.log('\'Artwork\' exists!');
} else {
console.log('\'Artwork\' does not exist!');
}
if ('Support' in doc) {
console.log('\'Support\' exists!');
} else {
console.log('\'Support\' does not exist!');
}
var subforumsDoc = {
Artwork: doc.Artwork,
Support: doc.Support,
Coding: thirdDoc
}
if (verbose >= 2) {
console.log('\nsubforumDoc: \n');
console.log(subforumsDoc);
}
res.render('index', { title: '3D Artist Forum', forums: subforumsDoc});
}catch(err){
return console.log(err)
}
})
关于javascript - 仅返回对象的第一个元素，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/53464160/