$gt and $gte for greater than in MongoDB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ query_result

intermediate

Find documents with age greater than 30

Given a collection users with documents containing an age field, which query returns all users older than 30?

MongoDB

db.users.find({ age: { $gt: 30 } })

A Returns all users with age less than or equal to 30

B Returns all users with age greater than or equal to 30

C Returns all users with age less than 30

D Returns all users with age strictly greater than 30

💡 Hint

Remember, $gt means strictly greater than, not including the value.

The $gt operator selects documents where the value of the field is strictly greater than the specified value. So { age: { $gt: 30 } } returns users older than 30, not including 30.

❓ query_result

intermediate

Find documents with age greater than or equal to 30

Which MongoDB query returns all users with age 30 or older?

MongoDB

db.users.find({ age: { $gte: 30 } })

A Returns users with age greater than or equal to 30

B Returns users with age strictly greater than 30

C Returns users with age less than 30

D Returns users with age less than or equal to 30

💡 Hint

Think about including the value 30 itself.

The $gte operator selects documents where the field value is greater than or equal to the specified value. So { age: { $gte: 30 } } includes users who are exactly 30 years old as well as older.

🧠 Conceptual

advanced

Difference between $gt and $gte

Which statement correctly describes the difference between $gt and $gte in MongoDB queries?

A <code>$gt</code> excludes the value specified, <code>$gte</code> includes it

B <code>$gt</code> includes the value specified, <code>$gte</code> excludes it

C Both <code>$gt</code> and <code>$gte</code> exclude the value specified

D Both <code>$gt</code> and <code>$gte</code> include the value specified

💡 Hint

Think about whether the boundary value is included or not.

$gt means strictly greater than, so it excludes the boundary value. $gte means greater than or equal to, so it includes the boundary value.

📝 Syntax

advanced

Identify the valid MongoDB query syntax for greater than

Which of the following MongoDB queries is syntactically correct to find documents where score is greater than 50?

A db.collection.find({ score > 50 })

B db.collection.find({ score: $gt 50 })

C db.collection.find({ score: { $gt: 50 } })

D db.collection.find({ score: { gt: 50 } })

💡 Hint

Remember the syntax for operators in MongoDB queries uses $ and colon.

The correct syntax uses { field: { $operator: value } }. Option C follows this pattern. Options B, C, and D are invalid syntax.

❓ optimization

expert

Optimizing queries using $gt and $gte with indexes

You have a large collection with an index on the price field. Which query will best use the index to find documents with price greater than or equal to 100?

A db.products.find({ price: { $gt: 99 } })

B db.products.find({ price: { $gte: 100 } })

C db.products.find({ price: { $gte: 100 }, price: { $lt: 200 } })

D db.products.find({ price: { $gt: 100 } })

💡 Hint

Think about the exact boundary value and index usage.

Option B directly queries for price >= 100, which matches the index efficiently. Option B uses $gt 99 which is equivalent but less clear. Option B adds an upper bound which may be useful but is not asked. Option B excludes 100, so it misses some documents.