$all operator for matching all elements in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find documents where the 'tags' array contains all specified elements.

MongoDB

db.collection.find({ tags: { [1]: ["red", "blue"] } })

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

A$in

B$exists

C$elemMatch

D$all

Attempts:

3 left

💡 Hint

Common Mistakes

Using $in instead of $all matches any one element, not all.

Using $elemMatch is for matching elements with conditions, not all elements.

Using $exists checks for field existence, not array contents.

The $all operator matches documents where the array contains all the specified elements.

2fill in blank

medium

Complete the query to find documents where the 'colors' array contains all of 'green' and 'yellow'.

MongoDB

db.products.find({ colors: { [1]: ["green", "yellow"] } })

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

A$elemMatch

B$in

C$all

D$size

Attempts:

3 left

💡 Hint

Common Mistakes

Using $in returns documents with any one of the elements, not all.

Using $size checks array length, not contents.

Using $elemMatch is for matching elements with conditions.

The $all operator ensures the array contains all specified elements.

3fill in blank

hard

Fix the error in the query to correctly find documents where 'features' contains all specified values.

MongoDB

db.items.find({ features: { [1]: ["wifi", "bluetooth"] } })

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

A$all

B$exists

C$elemMatch

D$in

Attempts:

3 left

💡 Hint

Common Mistakes

Using $in matches any element, not all.

Using $elemMatch is for complex conditions, not all elements.

Using $exists checks if the field exists, not its contents.

Only $all matches documents where the array contains all listed elements.

4fill in blank

hard

Fill both blanks to find documents where 'skills' array contains all specified skills and the 'level' is 'advanced'.

MongoDB

db.users.find({ skills: { [1]: ["python", "mongodb"] }, level: [2] })

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

A$all

B"advanced"

C"beginner"

D$in

Attempts:

3 left

💡 Hint

Common Mistakes

Using $in instead of $all for skills.

Using wrong string for level like "beginner".

Not quoting the level string.

Use $all to match all skills and specify the level as the string "advanced".

5fill in blank

hard

Fill all three blanks to find documents where 'tags' contains all specified tags, 'status' is 'active', and 'priority' is greater than 5.

MongoDB

db.tasks.find({ tags: { [1]: ["urgent", "client"] }, status: [2], priority: { [3]: 5 } })

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

A$all

B"active"

C$gt

D$in

Attempts:

3 left

💡 Hint

Common Mistakes

Using $in instead of $all for tags.

Not quoting the status string.

Using $lt or $lte instead of $gt for priority.

Use $all for tags, "active" string for status, and $gt operator for priority greater than 5.