define primary key myself and prevent creating the

I am two questions: 1- I want get by Id from database but operation is based on the key that is made automatically by MangoDB e.g _id. I want to search based on a field that I created myself e.g: id. for this porpouse I used following :

app.get('/:id',async(req,res)=>{
    try{
        const get=await product.findById({id:req.params.id});
        res.json(get);
    }
    catch(err){
        res.send(err);
    }
});

and get following output:

{"stringValue":"\"{ id: '1' }\"","valueType":"Object","kind":"Number","value":{"id":"1"},"path":"_id","reason":{"generatedMessage":true,"code":"ERR_ASSERTION","actual":false,"expected":true,"operator":"=="},"name":"CastError","message":"Cast to Number failed for value \"{ id: '1' }\" (type Object) at path \"_id\" for model \"product\""}

when creating the database the fied _id is created by mongodb and know as key. What command should I use to prevent this field from being created? how do i define key field myself in database or select my own definition field as the primary key on which to search?

CodePudding user response：

If you want to do that, you should use find method:

const get = await product.find({id:req.params.id});

I'm not sure, but I think that is not possible to avoid the creation of field _id in mongodb, although you can avoid the ObjectId type if you specify the field _id with a custom value (should be unique) when you insert the document.

But if you want to use a custom id value, you will need to use mongoose find method by you custom id as I indicated before. Since your custom id field should be unique you can use findOne in order to improve the performance of the query.