我有以下Schema,Base是一对一的信息收集器:
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" }]
});
和:
const BaseUserSchema = mongoose.Schema({
userId: { type: String },
baseId: { type: mongoose.Schema.Types.ObjectId },
created: { type: Date, default: Date.now() },
acceptedMembership: { type: Boolean, default: false },
isCreator: { type: Boolean, default: false }
});
(我有一个用于Message
看起来大致相同)后者在User
中被称为const User = mongoose.model("User", UserSchema);
当我创建一个新的Base时,我会自动将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,但是当我调用以下字段时,该字段不会填充:
Base.find({ creatorId: req.params.id })
.populate("users", "messages")
.exec()
.then(data => console.log(data));
我从console.log获得以下内容:
[ { 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前端创建基础,并且基础被添加到列表中时,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,控制台中的用户列表为空。
添加:忘记显示我在创建时如何填充用户列表:
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messages
返回users
。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" }],
是指错误的ref
。它一定要是
users: [{ type: mongoose.Schema.Types.ObjectId, ref: "BaseUser" }],
从
const BaseUser = mongoose.model("BaseUser", BaseUserSchema);
最后,我不确定是否需要这个,但我在每个待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" },
现在它就像一个魅力,没有额外的fetch