What are some examples of transactions in NoSQL databases?

What are some examples of transactions in NoSQL databases?

In NoSQL databases, transactions can vary widely. For instance, in MongoDB, you can use multi-document transactions to ensure atomicity across multiple documents. An example would be transferring funds between two accounts, where both the debit and credit operations must succeed together.

Can you give me a specific code example for that?

Sure! Here's a simple example in JavaScript using MongoDB:

const session = client.startSession();

session.startTransaction();
try {
    const debit = await accountsCollection.updateOne({ _id: senderId }, { $inc: { balance: -amount } }, { session });
    const credit = await accountsCollection.updateOne({ _id: receiverId }, { $inc: { balance: amount } }, { session });
    await session.commitTransaction();
} catch (error) {
    await session.abortTransaction();
} finally {
    session.endSession();
}

What happens if one of the operations fails?

If one of the operations fails, the transaction will be aborted, and all changes made during the transaction will be rolled back. This ensures data consistency.

Are there any limitations to transactions in NoSQL?

Yes, some NoSQL databases may have limitations on the types of operations that can be included in a transaction or may not support multi-document transactions at all. It's important to check the specific database documentation.