mongoDB – $all operator

The $all operator is used to selects the documents with the value of field is an array that contains all given elements.

where the value of a field is an array that contains all the specified elements. This operator behaves like

$and
operator.  $all syntax is

{ <field>: { $all: [ <value1> , <value2> ... ] }

{ degrees: { $all: [ "BS" , "MS" ] } }

This query will return all documents with degrees as “BS” and “MS”.