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?
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']);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.