Query.prototype.findOne()

Parameters

• [filter] «Object» mongodb selector

• [projection] «Object» optional fields to return

• [options] «Object» see setOptions()

• [callback] «Function» optional params are (error, document)

Returns:

• «Query» this

Declares the query a findOne operation. When executed, the first found document is passed to the callback.

Passing a callback executes the query. The result of the query is a single document.

• Note: conditions is optional, and if conditions is null or undefined, mongoose will send an empty findOne command to MongoDB, which will return an arbitrary document. If you’re querying by _id, use Model.findById() instead.

This function triggers the following middleware.

• findOne()

Example

const query  = Kitten.where({ color: 'white' });
query.findOne(function (err, kitten) {
  if (err) return handleError(err);
  if (kitten) {
    // doc may be null if no document matched
  }
});