High-level operations

The following high-level operations are described here after:

• FOR: Iterate over all elements of an array.
• RETURN: Produce the result of a query.
• FILTER: Restrict the results to elements that match arbitrary logical conditions.
• SORT: Force a sort of the array of already produced intermediate results.
• LIMIT: Reduce the number of elements in the result to at most the specified number, optionally skip elements (pagination).
• LET: Assign an arbitrary value to a variable.
• COLLECT: Group an array by one or multiple group criteria. Can also count and aggregate.
• REMOVE: Remove documents from a collection.
• UPDATE: Partially update documents in a collection.
• REPLACE: Completely replace documents in a collection.
• INSERT: Insert new documents into a collection.
• UPSERT: Update/replace an existing document, or create it in the case it does not exist.
• WITH: Specify collections used in a query (at query begin only).