MongoDB $set to update subarray, adding new entry instead of updating

Question

im trying to update an oject in a sub-array and instead of replacing and updating the data. it adds a new enetry.

controller.js:

const updateSubCategory = asyncHandler(async (req, res) => {
  const {
    dataArray
  } = req.body

  const categories = await Category.find({})

  if (categories) {
    await Category.updateOne({
      "SubCats._id": req.params.id
    }, {
      "$set": {
        SubCats: {
          name: dataArray[0],
          image: dataArray[1]
        }
      }
    }, {
      "multi": true
    })
    res.json({
      message: 'sub-category updated'
    })
  } else {
    res.status(404)
    throw new Error('Error')
  }
})

Answer 1

I think you need this, but i am not sure, if you dont need this, if you can give sample data and expected output in json.

You can try an example PlayMongo
It updates the fields inside not replace all the embeded document (your query does that).

const updateSubCategory = asyncHandler(async (req, res) => {
  const {
    dataArray
  } = req.body

  const categories = await Category.find({})

  if (categories) {
    await Category.updateOne({
      "SubCats._id": req.params.id
    }, {
      "$set": {
        "SubCats.name" : dataArray[0],
        "SubCats.image" : dataArray[1]
        }
      }
    }, {
      "multi": true
    })
    res.json({
      message: 'sub-category updated'
    })
  } else {
    res.status(404)
    throw new Error('Error')
  }
})