MongoDB MongoDB Query Language and Operators

Question 1

Which MongoDB query operator matches documents where a field value is greater than a specified value?

Accepted Answer

$gt

Answer

$gt (greater than) selects documents where the field value is strictly greater than the specified value.

Question 2

Which operator selects documents where a field value matches any value in a specified array?

Accepted Answer

$in

Answer

$in matches documents where the field value is equal to any value in the specified array.

Question 3

What does the $and operator do in a MongoDB query?

Accepted Answer

Returns documents where all conditions are true

Answer

$and performs a logical AND, returning only documents where all specified conditions are true.

Question 4

How do you apply a projection in a MongoDB find() query to return only specific fields?

Accepted Answer

db.col.find({filter}, {field: 1})

Answer

Projections are passed as the second argument to find(), with fields set to 1 to include them.

Question 5

What does the $ne operator match in a MongoDB query?

Accepted Answer

Documents where the field value is not equal to the specified value

Answer

$ne (not equal) matches all documents where the field value does not equal the specified value.

MongoDB Practice Test