How to build a conditional query in Mongoose?

Question

The following code works with no querystrings or one querystring only. In other words, simply going to /characters returns all

Answer 1

I am using destructing of objects for this task.

const filter = req.query.filter ? { _id: { $in: req.query.filter.split(',') } } : {};
const category = req.query.category ? { category: req.query.category } : {};
// more variables that you need and are empty objects if don't exist

const all = await Post.find({ ...filter, ...category }).exec();