how to remove an array element when using mongoose findone

Question

I have the following code. Image is an array and I want everything outputted except Path that exists within image. How can it be achieved ? image contains - ID, Title, Path

 if (dbRes !== null) {
            res.apiSuccess({
              
                town: dbRes.town,
                county: dbRes.county,
                postCode: dbRes.postCode,
                image: dbRes.image
  });
        } else {
            res.apiError(messages.product.not_found);
        }

Here is screenshot of output:

Edward Romero · Accepted Answer · 2020-09-13T21:28:25.697

UPDATE: OP shared the object which showed the definition of each parameter which changes the response traversal.

You can convert your dbres to object using mongoose build in function. And then just use delete command to delete the attribute from image before you pass it in the response.

Per the response above we are assuming that dbRes is an array of objects containing attributes image, town, county, and postCode. And image is also an array of objects.

     if (!dbRes) {
        // Convert db res to object and destructure attributes
        const dataArr = dbRes.toObject(); // Array of objects
        const response = dataArr.map((data) => {
           const {
              town,
              county,
              postCode,
              image = [] // Add default so that we don't have to check for null/undefined
           } = data;
           
           const newImageArr = image.map((imageData) => {
                // Delete path attribute from image object
                delete imageData.path;
                return imageData;  
           });

           return {
              town,
              county,
              postCode,
              image: newImageArr,
           }
        });
        
        res.apiSuccess(response);
    } else {
        res.apiError(messages.product.not_found);
    }

Resources:

Mongoose toObject Docs

Object Destructuring Tutorial

DB Level Omit

All these being said, if you don't need to use the path variable at all before you send the response then just omit it at the db level. This way you don't need to traverse object. Checkout the selection functionality of mongoose in this post https://stackoverflow.com/a/24348603/14167216

Can you provide what you’re seeing? Are you saying you still get the path key but undefined? Or do you still get the path key with data? — Edward Romero, Sep 13 '20 at 19:57
I'm getting town, country, postcode and all array image elements (id, title, path). path is not being removed — Orange Juice Jones, Sep 13 '20 at 20:13
Oh, image is an array, that’s why it didn’t work. Will update the response — Edward Romero, Sep 13 '20 at 21:11

score 1 · Answer 2 · answered Sep 13 '20 at 21:18

You can use dot notation and mongodb projections to exclude the path field from the array of images.

db.collection.findOne({
    _id: dataId
}, {
    "image.path": 0
})

The following query assumes that the document has an _id field and has a array of images at the first level. This query will return the entire document, only excluding the path fields in images array

how to remove an array element when using mongoose findone

2 Answers2