Convert SQL ORDER BY to MongoDB sort() or $sort Stage

ORDER BY to sort() / $sort

SQL's ORDER BY sorts results by one or more columns. In MongoDB, this maps to the .sort() cursor method for find() queries or the $sort aggregation stage for pipelines.

Example SQL

SELECT * FROM products
ORDER BY price DESC, name ASC

Generated MongoDB Query (find)

db.products.find({}).sort({
  price: -1,
  name: 1
})

Generated MongoDB Query (aggregate)

db.products.aggregate([
  {
    $sort: {
      price: -1,
      name: 1
    }
  }
])

Direction Mapping

SQL	MongoDB	Description
ASC	1	Ascending order (smallest to largest)
DESC	-1	Descending order (largest to smallest)
(default)	1	SQL defaults to ASC; MongoDB requires explicit direction

Multi-Field Sort

MongoDB respects the order of fields in the sort specification. In the example above, documents are first sorted by price descending, then by name ascending for documents with the same price. This matches SQL's behavior exactly.

Sort and Index Usage

For optimal performance, the sort fields and their directions should match an existing index. MongoDB can use an index to avoid an in-memory sort, which is subject to a 100 MB memory limit (configurable with allowDiskUse).

An index on { price: -1, name: 1 } would make the above query efficient. An index with reversed directions { price: 1, name: -1 } can also be used because MongoDB can traverse indexes in either direction.

Sort in Aggregation Pipeline

When using $sort in an aggregation pipeline, place it after $match and $group stages but before $limit and $skip for correct results. If $sort immediately precedes $limit, MongoDB optimizes this into a single operation that only tracks the top N results.