How to Sort Results in MongoDB: Syntax and Examples

In MongoDB, you sort query results using the sort() method, which takes an object specifying fields and sort order (1 for ascending, -1 for descending). For example, .sort({ age: 1 }) sorts documents by the age field in ascending order.

Syntax

The sort() method is used after a find() query to order the results. It takes an object where keys are field names and values are 1 for ascending or -1 for descending order.

• field: The document field to sort by.
• 1: Sort ascending (smallest to largest).
• -1: Sort descending (largest to smallest).

mongodb

db.collection.find(query).sort({ field1: 1, field2: -1 })

Example

This example shows how to sort a collection of users by their age in ascending order and then by name in descending order.

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db.users.find().sort({ age: 1, name: -1 })

Output

[
  { "name": "Bob", "age": 25 },
  { "name": "Alice", "age": 25 },
  { "name": "Charlie", "age": 30 }
]

Common Pitfalls

Common mistakes when sorting in MongoDB include:

• Using values other than 1 or -1 for sort order, which will be ignored or cause errors.
• Forgetting to chain sort() after find(), which means sorting won't apply.
• Sorting on fields that do not exist in documents, which returns results but may not be ordered as expected.

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/* Wrong: Using 0 instead of 1 or -1 */
db.users.find().sort({ age: 0 })

/* Right: Use 1 or -1 */
db.users.find().sort({ age: 1 })

Quick Reference

Usage	Description
{ field: 1 }	Sort by field ascending
{ field: -1 }	Sort by field descending
{ field1: 1, field2: -1 }	Sort by field1 ascending, then field2 descending
Use after find()	Apply sorting to query results

Key Takeaways

Use the sort() method with { field: 1 } for ascending or { field: -1 } for descending order.

Always chain sort() after find() to apply sorting to query results.

Sorting on non-existing fields returns results but may not be ordered as expected.

Only use 1 or -1 as sort values; other values are invalid.

You can sort by multiple fields by including them in the sort object.