Give every employee a salary raise of `5000`. Return all employees sorted by salary descending.
Problem Statement
Examples
Input: employees collection: +-----+---------+--------+ | _id | name | salary | +-----+---------+--------+ | 1 | Alice | 90000 | | 2 | Bob | 60000 | | 3 | Charlie | 75000 | +-----+---------+--------+
Output: +-----+---------+--------+ | _id | name | salary | +-----+---------+--------+ | 1 | Alice | 95000 | | 3 | Charlie | 80000 | | 2 | Bob | 65000 | +-----+---------+--------+
Explanation: The target document is modified according to the update operators and the updated document is returned.
Complexity
Time Complexity: -
Space Complexity: -
Hints
Editorial & Approach
Problem Overview & Intuition
To solve "Bulk Increment ($inc on Many)", we query the MongoDB document store. The goal is to give every employee a salary raise of `5000`. return all employees sorted by salary descending. Using a targeted find query, the database engine filters and structures the BSON documents efficiently.
Step-by-Step Approach
- Identify Target Collection: Access the collection through the
dbinstance. - Construct Query / Pipeline: Build the query filter with appropriate comparison operators.
- Resolve Cursor: Invoke
.toArray()to transform the query cursor into the required array of documents.
Optimal Implementation (MongoDB)
function solve(db) {
db.employees.updateMany({}, { $inc: { salary: 5000 } });
return db.employees.find({}).sort({ salary: -1 }).toArray();
}
Complexity Analysis
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.