You want to know how many types of items you have in each category. Which query does this?

June 25, 2021 Team Pa 0 Comment

MongoDB LinkedIn Assessment Questions and Answers

db.product.group({_id: “$category”, count: {$sum:1}})
db.product.aggregate($sum: {_id: “$category”, count: {$group:1}})
db.product.aggregate($group: {_id: “$category”, count: {$sum:1}})
db.product.aggregate($count: {_id: “$category”, count: {$group:1}})

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You have a collection of thousands of students. You’d like to return the second set of 20 documents from the sorted collection. What is the proper order in which to apply the operations?You have a collection of thousands of students. You’d like to return the second set of 20 documents from the sorted collection. What is the proper order in which to apply the operations?

limit, skip, sort sort, limit, skip limit, sort, skip sort, skip, limit[...]

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Assuming you have customers collection with a firstName and lastName field, which is the correct MongoDB shell command to create an index on lastName, then firstName both ascending?Assuming you have customers collection with a firstName and lastName field, which is the correct MongoDB shell command to create an index on lastName, then firstName both ascending?

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Which MongoDB shell command deletes a single document?Which MongoDB shell command deletes a single document?

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