MongoDB Coding Challenges Solutions

Write a Query to Find Users by Age Range

Create a MongoDB query to find users aged between 25 and 35, projecting only their name and age.

Expected output: Documents with name and age fields for users aged 25 to 35.

Hint: Use $gte and $lte operators with projection.

Create an Aggregation Pipeline to Count Orders by Status

Write an aggregation pipeline that groups orders by their status and counts the number of orders per status.

Expected output: Documents showing each status and corresponding order count.

Hint: Use $group with $sum accumulator.

Optimizing query performance involves creating appropriate indexes, projecting only necessary fields, and filtering data early in queries or aggregation pipelines.

Embed data when related data is accessed together frequently and is relatively static. Use references when related data is large, changes frequently, or is accessed independently.

The aggregation framework processes data records and returns computed results, enabling complex data transformations, grouping, and calculations within the database.