Multi-document transactions in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start a transaction session in MongoDB.

MongoDB

const session = client.startSession();
await session.[1]();

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AstartTransaction

BcommitTransaction

CendSession

DabortTransaction

Attempts:

3 left

💡 Hint

Common Mistakes

Using commitTransaction instead of startTransaction.

Calling endSession before starting the transaction.

The startTransaction() method begins a transaction in the session.

2fill in blank

medium

Complete the code to commit the transaction after operations.

MongoDB

await session.[1]();

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AstartTransaction

BabortTransaction

CcommitTransaction

DendSession

Attempts:

3 left

💡 Hint

Common Mistakes

Using abortTransaction instead of commitTransaction.

Calling startTransaction again instead of committing.

The commitTransaction() method saves all changes made during the transaction.

3fill in blank

hard

Fix the error in the code to abort the transaction on failure.

MongoDB

try {
  await session.startTransaction();
  // operations
  await session.commitTransaction();
} catch (error) {
  await session.[1]();
}

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

AstartTransaction

BcommitTransaction

CendSession

DabortTransaction

Attempts:

3 left

💡 Hint

Common Mistakes

Calling commitTransaction in the catch block.

Calling startTransaction again inside catch.

On error, abortTransaction() cancels all changes made in the transaction.

4fill in blank

hard

Fill both blanks to run operations inside a transaction session.

MongoDB

const session = client.startSession();
try {
  await session.[1]();
  await collection.[2](doc, { session });
  await session.commitTransaction();
} finally {
  await session.endSession();
}

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AstartTransaction

BinsertOne

CupdateOne

DabortTransaction

Attempts:

3 left

💡 Hint

Common Mistakes

Using updateOne instead of insertOne for inserting.

Not starting the transaction before operations.

Start the transaction with startTransaction() and perform the insert with insertOne() inside the session.

5fill in blank

hard

Fill all three blanks to update two documents atomically in a transaction.

MongoDB

const session = client.startSession();
try {
  await session.[1]();
  await collection1.[2]({ _id: 1 }, { $set: { status: 'done' } }, { session });
  await collection2.[3]({ _id: 2 }, { $inc: { count: 1 } }, { session });
  await session.commitTransaction();
} catch (e) {
  await session.abortTransaction();
} finally {
  await session.endSession();
}

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

AstartTransaction

BupdateOne

DinsertOne

Attempts:

3 left

💡 Hint

Common Mistakes

Using insertOne instead of updateOne for updates.

Not starting the transaction before updates.

Start the transaction, then update documents in both collections using updateOne() inside the session.