$ne (query predicate operator)

Match Document Fields That Are Not Equal

The following example returns movies where runtime is greater than 1000 minutes and rated is not equal to "G". Because $ne also matches documents that don't contain the rated field, the query returns movies even when the rating data is unavailable:

db.movies.find(
   { rated: { $ne: "G" }, runtime: { $gt: 1000 } },
   { _id: 0, title: 1, runtime: 1, rated: 1 }
)

[
  {
    runtime: 1256,
    title: 'Centennial'
  },
  {
    runtime: 1140,
    title: 'Baseball',
    rated: 'TV-PG'
  }
]

Update Based on Not Equal Embedded Document Fields

The following example sets the highestRated field based on a $ne comparison on a field in an embedded document. The updateMany() operation searches for an embedded document, imdb, with a subfield named rating. It uses $set to update the highestRated field to false in each document where the value of rating is not equal to 9.3 or where the rating subfield does not exist:

db.movies.updateMany(
   { "imdb.rating": { $ne: 9.3 } },
   { $set: { "highestRated": false } }
)

{
  acknowledged: true,
  insertedId: null,
  matchedCount: ...,
  modifiedCount: ...,
  upsertedCount: 0
}

The SQL equivalent to this query is:

UPDATE movies SET highestRated = false WHERE imdb_rating != 9.3

The inequality operator $ne is not very selective since it often matches a large portion of the index. As a result, in many cases, a $ne query with an index may perform no better than a $ne query that must scan all documents in a collection. See also Create Selective Queries.

Arrays

When comparing arrays, $ne behaves differently depending on whether you pass a scalar or an array as the comparison value.

• Scalar comparison: $ne matches documents where the scalar value is not present as an element in the array, including documents that don't have the field.

• Exact array comparison: $ne matches documents where the field array is not identical to the specified array, including documents with a different element order, a different number of elements, or a missing field.

The following examples return movies with a runtime over 1000 minutes to demonstrate each behavior.

db.movies.find(
   { genres: { $ne: "Drama" }, runtime: { $gt: 1000 } },
   { _id: 0, title: 1, genres: 1 }
)

[
  {
    genres: [ 'Documentary', 'History', 'Sport' ],
    title: 'Baseball'
  }
]

db.movies.find(
   { genres: { $ne: [ "Drama" ] }, runtime: { $gt: 1000 } },
   { _id: 0, title: 1, genres: 1 }
)

[
  {
    genres: [ 'Action', 'Adventure', 'Drama' ],
    title: 'Centennial'
  },
  {
    genres: [ 'Documentary', 'History', 'Sport' ],
    title: 'Baseball'
  }
]