填充不适用于 $regex mongodb

Question

I have this query which is working fine but child document is not populating when i use regex

let u = new RegExp(`${req.params.username}`, 'i');

let user = await User.findOne({
  userName: { $regex: u },
}).populate({
  path: 'profiles',
  populate: {
    path: 'companyId',
    match: { _id: { $exists: true } },
  },
});

It always return child field as empty

This query is working fine without regex

let user = await User.findOne({
  userName: req.params.username,
}).populate({
  path: 'profiles',
  populate: {
    path: 'companyId',
    match: { _id: { $exists: true } },
  },
});

Answer 1

Please try the following code, this is tested code, '.*' means if the string matching anywhere like the string is lookup and I want to search with the look it will return all the records which contain look.

let user = await User.findOne({
  userName: {
        $regex: `.*${req.params.username}.*`,
        $options: 'i'
      },
}).populate({
      path: 'profiles',
      populate: {
      path: 'companyId',
      match: { _id: { $exists: true } },
   },
});