I'm trying to filter my pets by category, I have the following model of pets:

const Pet = mongoose.model(
    'Pet',
    new Schema({
        name: {
            type: String,
            required: true,
        },
        age: {
            type: Number,
            required: true,
        },
        description: {
            type: String,
        },
        weight: {
            type: Number,
            required: true,
        },
        color: {
            type: String,
            required: true,
        },
        images: {
            type: Array,
            required: true,
        },
        available: {
            type: Boolean,
        },
        category: Object,
        user: Object,
        adopter: Object,
    }, { timestamps: true }),
);

module.exports = Pet;

<iframe name="sif1" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

when I try to get the data through postman it returns an empty array as a response.

my code to filter by category:

static async getByCategory(req, res) {

        const id = req.params.id;

        // check if id is valid
        if (!ObjectId.isValid(id)) {
            res.status(422).json({ msg: 'Invalid ID' });
            return;
        }

        const pets = await Pet.find({ 'category._id': id }).sort('-createdAt');

        if (!pets) {
            res.status(404).json({ msg: 'Pets not found!' });
            return;
        }

        res.status(200).json({ pets });
    }

<iframe name="sif2" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

it's my first time using mongodb so i'm not sure what's wrong.

CodePudding user response：

Could you check that your mongodb indeed has a field 'category._id'?

CodePudding user response：

id being passed from the client side is string and the one which is saved in the db is ObjectId. Convert the string to Mongoose ObjectId before Pet.find().

const id = mongoose.Types.ObjectId(req.params.id);

const pets = await Pet.find({ 'category._id': id }).sort('-createdAt');

Don't forget to import 'mongoose'.