Use an aggregation pipeline with `$match` to find all orders with `status: "shipped"`.

Problem Statement

<p>Use an aggregation pipeline with <code>$match</code> to find all <code>orders</code> with <code>status: "shipped"</code>.</p>

Examples

Input: orders collection: +-----+--------+---------+--------+ | _id | item | status | amount | +-----+--------+---------+--------+ | 1 | Laptop | shipped | 999 | | 2 | Phone | pending | 699 | | 3 | Tablet | shipped | 499 | +-----+--------+---------+--------+

Output: +-----+--------+---------+--------+ | _id | item | status | amount | +-----+--------+---------+--------+ | 1 | Laptop | shipped | 999 | | 3 | Tablet | shipped | 499 | +-----+--------+---------+--------+

Explanation: The query retrieves all documents from the collection that satisfy the specified filter criteria.

Complexity

Time Complexity: -

Space Complexity: -

Hints

💡 Hint 1: Use db.<collection>.aggregate([ ... ]) to run a multi-stage data processing pipeline. 💡 Hint 2: Order pipeline stages logically (e.g. $match early to filter documents before processing). 💡 Hint 3: Convert the aggregation cursor using .toArray() at the end of the function.

Editorial & Approach

Problem Overview & Intuition

To solve "Aggregation: $match Stage", we query the MongoDB document store. The goal is to use an aggregation pipeline with `$match` to find all orders with `status: "shipped"`. Using an aggregation pipeline, the database engine filters and structures the BSON documents efficiently.

Step-by-Step Approach

Identify Target Collection: Access the collection through the db instance.
Construct Query / Pipeline: Build the aggregation stages ($match, $group, $sort, etc.).
Resolve Cursor: Invoke .toArray() to transform the query cursor into the required array of documents.

Optimal Implementation (MongoDB)

function solve(db) {
  return db.orders.aggregate([{ $match: { status: "shipped" } }]);
}

Complexity Analysis

Time Complexity O(N) pipeline traversal through aggregation stages.

Space Complexity O(M) intermediate document buffer in aggregation pipeline.

Key Considerations & Edge Cases

Empty Collections: If no documents match, the query cleanly returns an empty array [].
Missing / NULL Fields: Missing fields in documents are handled safely without throwing runtime exceptions.
Type Coercion: BSON types (ObjectId, Numbers, Strings) are compared strictly according to MongoDB specifications.

Aggregation: $match Stage

Medium

Use an aggregation pipeline with $match to find all orders with status: "shipped".

Example Scenarios

1Example 1

Input:

orders collection

_id	item	status	amount
1	Laptop	shipped	999
2	Phone	pending	699
3	Tablet	shipped	499

Output:

_id	item	status	amount
1	Laptop	shipped	999
3	Tablet	shipped	499

Explanation:

The query retrieves all documents from the collection that satisfy the specified filter criteria.

MongoDB Editor

Loading Editor...

Query Results (JSON)

Run your MongoDB code to see results here.