Aggregate.prototype.project()

Parameters
  • arg «Object|String» field specification
Returns:
  • «Aggregate»

Appends a new $project operator to this aggregate pipeline.

Mongoose query selection syntax is also supported.

Examples:

  1. // include a, include b, exclude _id
  2. aggregate.project("a b -_id");
  4. // or you may use object notation, useful when
  5. // you have keys already prefixed with a "-"
  6. aggregate.project({a: 1, b: 1, _id: 0});
  8. // reshaping documents
  9. aggregate.project({
  10.     newField: '$b.nested'
  11.   , plusTen: { $add: ['$val', 10]}
  12.   , sub: {
  13.        name: '$a'
  14.     }
  15. })
  17. // etc
  18. aggregate.project({ salary_k: { $divide: [ "$salary", 1000 ] } });