Node.js 猫鼬';s populate()不从数据库返回数据
我有以下模式,Base是所有信息收集器的模式:Node.js 猫鼬';s populate()不从数据库返回数据,node.js,mongodb,reactjs,mongoose,Node.js,Mongodb,Reactjs,Mongoose,我有以下模式,Base是所有信息收集器的模式: const BaseSchema = mongoose.Schema({ creatorId: { type: mongoose.Schema.Types.ObjectId, required: true }, title: { type: String, required: true }, created: { type: Date, default: Date.now() }, users: [{ type: mongoose.
const BaseSchema = mongoose.Schema({
creatorId: { type: mongoose.Schema.Types.ObjectId, required: true },
title: { type: String, required: true },
created: { type: Date, default: Date.now() },
users: [{ type: mongoose.Schema.Types.ObjectId, ref: "User" }],
messages: [{ type: mongoose.Schema.Types.ObjectId, ref: "Message" }]
});
以及:
(我有一个用于消息的,看起来差不多)
后者在const User=mongoose.model(“User”,UserSchema)中称为User
代码>
当我创建一个新基地时,我会自动将一个用户添加到其中的列表中。在DB中,我可以看到用户确实存在,但当我调用以下命令时,字段不会填充:
Base.find({ creatorId: req.params.id })
.populate("users", "messages")
.exec()
.then(data => console.log(data));
我从console.log获得以下信息:
[ { created: 2018-09-05T03:41:45.416Z,
users: [],
messages: [],
_id: 5b8f508b2760c5329c13a9be,
creatorId: 5b86f7970cd98b2004969bf0,
title: 'testBase1',
__v: 1 } ]
当我第一次通过React-front-end创建base时,base被添加到一个列表中,我看到users.length
是1,或者是自动创建的用户的长度。但是,当我刷新页面时,控制台中的userlist是空的
添加:
忘记显示如何在创建时填充用户列表:
router.post("/add", jwtAuth, (req, res) => {
Base.create({
creatorId: req.body.userId,
title: req.body.title
}).then(baseInfo => {
BaseUser.create({
userId: req.body.username,
baseId: baseInfo._id,
created: Date.now(),
acceptedMembership: true,
isCreator: true
})
.then(baseuser => {
baseInfo.users.push(baseuser);
return baseInfo.save();
})
.then(base => res.json(base.serialize()));
});
});
回答:
.populate("users", "messages")
首先,将从用户
返回消息
。它必须是两个单独的条目,如下所示:
.populate("users")
.populate("messages")
然后,在模型中
users: [{ type: mongoose.Schema.Types.ObjectId, ref: "User" }],
指错误的ref
。一定是这样
users: [{ type: mongoose.Schema.Types.ObjectId, ref: "BaseUser" }],
从
最后,我不确定是否需要这样做,但我在每个要填充的项目中添加了一个ref
:
baseId: { type: mongoose.Schema.Types.ObjectId, required: true, ref: "Base" },
baseId: { type: mongoose.Schema.Types.ObjectId, ref: "Base" },
现在,它就像一个符咒,没有额外的fetch
const BaseUser = mongoose.model("BaseUser", BaseUserSchema);
baseId: { type: mongoose.Schema.Types.ObjectId, required: true, ref: "Base" },
baseId: { type: mongoose.Schema.Types.ObjectId, ref: "Base" },