Query selectors

The following is a list of all supported methods that are supported on any Mongoid class. The following table states the attributes of the query selectors, their usage, and description:

:all	Book.all(reviews: ['good', 'excellent'])	This finds all the documents where the field (typically an array) matches all the values in the array. So, this means that reviews is an array inside the Book document, and it must contain at least two values good and excellent. In case reviews is an embedded document, we can also write this like the following code: Book.all("reviews.content" => ['good', 'excellent'])
:exists	Author.exists(books_count: true)	This finds all the documents in which the field exists.
:gt/:gte/:lt/:lte	Author.gt(books_count: 1) Author.lte(books_count: 10)	This finds all the documents in which count is greater than (:gt) or greater than or equal to (:gte) and lesser than (:lt) and lesser than or equal to (:lte).
:in :nin	Author.in(name: ['Gautam', 'Charles...