Partial indexes with filter in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a partial index on the 'status' field where status is 'active'.

MongoDB

db.users.createIndex({ status: 1 }, { partialFilterExpression: { status: [1] } })

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

A"active"

Bactive

C1

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes around string values in the filter expression.

Using a boolean or number instead of a string.

The partialFilterExpression requires the value to be a string, so we use "active" with quotes.

2fill in blank

medium

Complete the code to create a partial index on the 'age' field only for documents where age is greater than 18.

MongoDB

db.people.createIndex({ age: 1 }, { partialFilterExpression: { age: { [1]: 18 } } })

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' instead of 'greater than'.

Using $eq which means 'equal to' instead of 'greater than'.

The operator $gt means 'greater than', so it filters documents where age is greater than 18.

3fill in blank

hard

Fix the error in the partial index creation by completing the filter expression correctly.

MongoDB

db.orders.createIndex({ total: 1 }, { partialFilterExpression: { total: { [1]: 100 } } })

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

A$gte

Bgte

C$greater

D=>

Attempts:

3 left

💡 Hint

Common Mistakes

Leaving out the dollar sign in the operator.

Using invalid operators like 'gte' or '=>'.

The correct MongoDB operator for 'greater than or equal' is $gte with a dollar sign.

4fill in blank

hard

Fill both blanks to create a partial index on 'category' where category is either 'books' or 'magazines'.

MongoDB

db.library.createIndex({ category: 1 }, { partialFilterExpression: { category: { [1]: [[2]] } } })

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

A$in

B"books", "magazines"

C"books", "movies"

D$nin

Attempts:

3 left

💡 Hint

Common Mistakes

Using $nin which means 'not in' instead of $in.

Including wrong values like 'movies' instead of 'magazines'.

The $in operator filters documents where the field matches any value in the array. The array should contain "books" and "magazines".

5fill in blank

hard

Fill both blanks to create a partial index on 'score' where score is between 50 and 100 inclusive.

MongoDB

db.scores.createIndex({ score: 1 }, { partialFilterExpression: { score: { [1]: 50, [2]: 100 } } })

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

A$gte

B$lte

C$gt

D$lt

Attempts:

3 left

💡 Hint

Common Mistakes

Using $gt or $lt which exclude boundary values.

Mixing up $gte and $lte operators.

Use $gte for 'greater than or equal to' 50, $lte for 'less than or equal to' 100.