collection.findOne

Mongo documentation

Returns one document that satisfies the specified query criteria on the collection or view. If multiple documents satisfy the query, this method returns the first document according to the natural order which reflects the order of documents on the disk. In capped collections, natural order is the same as insertion order. If no document satisfies the query, the method returns null.

Arguments

1. query (String|ObjectId|Object)

2. [options] (Object|String|Array): If the options is a string, it will be parsed as the projections to select.

3. [callback] (function)

Returns

A promise.

Example

users.findOne({name: 'foo'}).then((doc) => {});

users.findOne({name: 'foo'}, 'name').then((doc) => {
  // only the name projection will be selected
});
users.findOne({name: 'foo'}, { projection: { name: 1 } }); // equivalent

users.findOne({name: 'foo'}, '-name').then((doc) => {
  // all the fields except the name projection will be selected
});
users.findOne({name: 'foo'}, { projection: {name: -1} }); // equivalent