如何在JavaScript中使用.populate（）

发布于 2025-02-05 13:17:14 字数 529 浏览 5 评论 0 原文

的集合

CR

我有一个名为“我想做的事情”

let cre = await CR.find({myid: "xxxxxx"})

就是这样查询：而且我还有一个称为 cla 的集合，但是我需要根据 cre /代码>。 CRE的结果将返回一个class_id，在其中我需要用来查询 cla 集合以查找 _id 。在所有这些结束时，我想理想地合并两者，我相信您可以通过 .populate（）进行操作，然后将其发送到Teh前端。

我已经尝试过：

 let cre = await cr.find({myid: "xxx"}).populate('loc').populate('desc').populate('dt');

但这不起作用。我该如何解决？

原文

I have a collection called

CR

what I want to do is query CR like so:

let cre = await CR.find({myid: "xxxxxx"})

and i also have a collection called cla, but that one i need to query based off of the results of cre. The results of cre will return a class_id, in which I need to use to query the cla collection to find the _id. At the end of all of this, I want to ideally merge the two, which I believe you can do through .populate(), and then send it to teh front-end as one.;

I have tried this:

 let cre = await cr.find({myid: "xxx"}).populate('loc').populate('desc').populate('dt');

but this isn't working. how can I fix this?

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

桃扇骨 2025-02-12 13:17:14

这可能是由于图式造成的，但这是干净且易于使用的方式。

 let cre = await cr.find({myid: "xxx"}).populate(['loc','desc','dt']);

It may be due to schemas, but this is how it's clean and simple to use;

 let cre = await cr.find({myid: "xxx"}).populate(['loc','desc','dt']);

回复收藏 0 原文

旧瑾黎汐 2025-02-12 13:17:14

首先，您可以在 cr 收集模式中采用 cla 收集“ _id”。在 cr 集合的模式中，请参阅 cla模型ID ，

const creSchema = mongoose.Schema({
    name: String,
    classnId: { type: mongoose.Types.ObjectId, ref: "Cla" }
});

然后您可以像这样填充，

const cres = await CR.find({}).populate({path:'classnId', select:'columnName'});

希望这将解决您的问题。

注意：在填充时，您可以按空格给出多个列名，如果您在这样的列名之前给出负名（-columnname），那么该列将无法显示何时调用API。

Firstly, you can take cla collection "_id" in CR collection schema. In schema of CR collection refer to cla model id like this,

const creSchema = mongoose.Schema({
    name: String,
    classnId: { type: mongoose.Types.ObjectId, ref: "Cla" }
});

Then you can populate like,

const cres = await CR.find({}).populate({path:'classnId', select:'columnName'});

Hopefully, this will solve your issue.

Note: There in populating you can give multiple column names by space and if you give a minus before a column name like this (-columnName) then that column will not show when you will call the API.

回复收藏 0 原文

~没有更多了~