Best way to check category owner

Question

Task model

const TaskSchema = new Schema({
    userId: {
        type: Schema.Types.ObjectId,
        ref: 'User'
    },
    title: {
        type: Schema.Types.String,
        required: true
    },
    description: Schema.Types.String,
    createdDate: {
        type: Schema.Types.Date,
        default: Date.now()
    },
    position: {
        type: Schema.Types.Number,
        default: 0
    },
    categoryId: [{
        type: Schema.Types.ObjectId,
        ref: 'Category'
    }]
});

Category model

const CategorySchema = new Schema({
    title: {
        type: Schema.Types.String,
        required: true
    },
    description: {
        type: Schema.Types.String,
    },
    categoryThumbnail: {
        type: Schema.Types.String,
        default: ''
    },
    userId: {
        type: Schema.Types.ObjectId,
        ref: 'User',
        required: true
    },
    createdDate: {
        type: Schema.Types.Date,
        default: Date.now()
    }
});

When creating a task, the user can assign a category. Do I need to check the category owner before adding the task to Mongodb. If so, what is the best way to do this? Options: 1. Make a request to the database for all categories and check the user id. 2. Store the category id in the user document and, upon receipt of the request, check this list.

Answer 1

So if the User can create multiple categories and each category is only accessible by the User who created it you have a one-to-many association. In this situation it seems your Option 1 is what you want. Keep the user id on the category and then query all categories that have the user id you're looking for.

Edit:

If possible, I would recommend that you limit the categories the user sees when creating a task to only be categories created by that user. If that is not possible, then you could do one query to grab all the categories from the list of category IDs sent to the server and loop through the results checking if the user IDs are the same.

Category.find({
    'id': { $in: [
        mongoose.Types.ObjectId('4ed3ede8844f0f351100000c'),
        mongoose.Types.ObjectId('4ed3f117a844e0471100000d'), 
        mongoose.Types.ObjectId('4ed3f18132f50c491100000e')
    ]}
}, function(err, docs){
    docs.forEach(item => {
        return item.userId === userId; //compare to userId that sent the request
    }
});