mongo-query

Component that implements the complete MongoDB query JSON API to operate on individual documents.

Example

var query = require('mongo-query');

// our sample document
var obj = {
  name: 'Tobi',
  age: 8,
  location: { country: 'Canada', zip: 123 },
  likes: [{ id: 1, name: 'Food' }, { id: 2, name: 'Stuff' }]
};

// run an operation and get changes
var changes = query(obj, { $set: { 'location.country': 'US' } });

Features

• Transactional. If an op fails, the others are rolled back.
• Precise modification logs. Ops return an array of change objects.
  • Noops are excluded.
  • Before/after values are provided.
  • Whether the op triggered the creation of a new array.
• Error messages almost exactly match MongoDB's.
• Query support. Allows for support of the positional operator.
• Wide test coverage.

API

query(obj, filter, modifier, opts)

• Executes the modifier on obj provided they match filter.
• Returns an array of change objects (see below). If the modifier does not alter the object the array will be empty.
• Options:
  • strict if true, only modifies if filter has a match (false).

query.filter(query)

Returns a Query object to perform tests on.

Example: query.filter({ a: { $gt: 3 } }).test({ a: 1 }). For the complete filter API refer to filtr.

query.get(obj, key)

Gets the key from the given obj, which can use dot notation.

Example: query.get(obj, 'some.key').

query.set(obj, key, val)

Sets the key on obj with the given val. Key can use dot notation.

change

All change objects contain:

• key: the key that was affected. If the positional operator was used, the key is rewritten with dot notation (eg: comments.3.date).
• op: the type of operation that was performed

Depending on the type of operation they can contain extra fields.

$set

• value that we set

$inc

• value value that we increment by

$pop

• value value that was popped
• shift if true, it was a shift instead of a pop

$rename

• value new name

$push

• value value that was pushed

$pushAll

• value array of values that were pushed

$pull

• value array of values that were pulled

$pullAll

• value array of values that were pulled

$unset

• value (undefined)

$addToSet

• value array of values that were added