Query filter syntax in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find documents where the field "age" is exactly 25.

MongoDB

db.collection.find({"age": [1] })

Drag options to blanks, or click blank then click option'

A25

B"age"

C{ $gt: 25 }

D[25]

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around the number, which makes it a string.

Using an array instead of a single value.

Using a comparison operator when exact match is needed.

The filter {"age": 25} finds documents where the age field equals 25 exactly.

2fill in blank

medium

Complete the code to find documents where "score" is greater than 80.

MongoDB

db.collection.find({"score": { [1]: 80 }})

Drag options to blanks, or click blank then click option'

A$lt

B$eq

C$gt

D$ne

Attempts:

3 left

💡 Hint

Common Mistakes

Using "$lt" which means less than.

Using "$eq" which means equal to.

Using "$ne" which means not equal.

The operator "$gt" means "greater than". So this filter finds documents with score > 80.

3fill in blank

hard

Fix the error in the query to find documents where "status" is not "active".

MongoDB

db.collection.find({"status": { [1]: "active" }})

Drag options to blanks, or click blank then click option'

A$ne

B$eq

C$gt

D$in

Attempts:

3 left

💡 Hint

Common Mistakes

Using "$eq" which matches only "active" status.

Using "$gt" which is for greater than comparisons.

Using "$in" which expects an array of values.

The operator "$ne" means "not equal to". It filters documents where status is not "active".

4fill in blank

hard

Fill both blanks to find documents where "age" is at least 18 and less than 30.

MongoDB

db.collection.find({"age": { [1]: 18, [2]: 30 }})

Drag options to blanks, or click blank then click option'

A$gte

B$lt

C$lte

D$ne

Attempts:

3 left

💡 Hint

Common Mistakes

Using "$gt" instead of "$gte" excludes 18.

Using "$lte" includes 30 which is not wanted.

Using "$ne" which is unrelated.

"$gte" means "greater than or equal to" 18, and "$lt" means "less than" 30, so this finds ages between 18 and 29.

5fill in blank

hard

Fill all three blanks to find documents where "score" is greater than 50, "status" is "active", and "age" is less than 40.

MongoDB

db.collection.find({"score": { [1]: 50 }, "status": [2], "age": { [3]: 40 }})

Drag options to blanks, or click blank then click option'

A$gt

B"active"

C$lt

D$ne

Attempts:

3 left

💡 Hint

Common Mistakes

Using "$ne" instead of "$gt" or "$lt".

Not quoting the string "active".

Mixing up greater than and less than operators.

"$gt" filters scores greater than 50, "status" must equal "active", and "$lt" filters ages less than 40.