Atlas triggers overview in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a trigger that runs on document insert.

MongoDB

exports = function(changeEvent) { if (changeEvent.operationType === '[1]') { console.log("Document inserted"); } };

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Areplace

Bupdate

Cdelete

Dinsert

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'update' or 'delete' instead of 'insert'.

The trigger listens for the insert operation type to run when a new document is added.

2fill in blank

medium

Complete the code to access the full document after an update in a trigger.

MongoDB

exports = function(changeEvent) { const fullDoc = changeEvent.[1]; console.log(fullDoc); };

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AdocumentKey

BfullDocument

CupdateDescription

Dns

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'documentKey' which only has the document ID.

The fullDocument field contains the entire document after the update.

3fill in blank

hard

Fix the error in the trigger code to correctly check for a delete operation.

MongoDB

exports = function(changeEvent) { if (changeEvent.operationType === '[1]') { console.log("Document deleted"); } };

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Adrop

Bremove

Cdelete

Ddestroy

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'remove' or 'drop' which are not valid operationType values.

The correct operationType for a delete event is delete.

4fill in blank

hard

Fill both blanks to filter trigger events only for updates on the 'status' field.

MongoDB

exports = function(changeEvent) { if (changeEvent.operationType === '[1]' && changeEvent.updateDescription.updatedFields.[2] !== undefined) { console.log("Status field updated"); } };

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Aupdate

Binsert

Cstatus

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'insert' instead of 'update' or wrong field names.

The trigger checks for update operations and specifically if the status field was changed.

5fill in blank

hard

Fill all three blanks to log the document ID and new value of 'score' after an update.

MongoDB

exports = function(changeEvent) { const docId = changeEvent.[1]._id; const newScore = changeEvent.updateDescription.updatedFields.[2]; console.log(`Document ID: ${docId}, New Score: ${newScore}`); if (changeEvent.operationType === '[3]') { /* additional logic */ } };

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

AdocumentKey

Bscore

Cupdate

DfullDocument

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'fullDocument' for ID or wrong operationType.

The documentKey holds the document ID, score is the updated field, and the operationType is update.