batch

Episode 2 - Transactional Batch

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Transaction batch aims at creating a single transactional unit that will either commit or rollback as a whole.

In the example, we create the OnDotNet show along with 3 episodes:

TransactionalBatchResponse createShowResponse = await container.CreateTransactionalBatch(new PartitionKey(showName))
    .CreateItem<Show>(Show.Create(showName))
    .CreateItem<Episode>(Episode.Create(showName, "Cosmos DB SDK Features 1"))
    .CreateItem<Episode>(Episode.Create(showName, "Cosmos DB SDK Features 2"))
    .CreateItem<Episode>(Episode.Create(showName, "Cosmos DB SDK Features 3"))
    .ExecuteAsync();

The result contains one response for each operation as a TransactionalBatchOperationResult and can be obtained through the GetOperationResultAtIndex method using the operation index:

TransactionalBatchOperationResult<Show> showResult = createShowResponse.GetOperationResultAtIndex<Show>(0);
theShow = showResult.Resource;
TransactionalBatchOperationResult<Episode> episode1Result = createShowResponse.GetOperationResultAtIndex<Episode>(1);
episode1 = episode1Result.Resource;

If any single of these items fails, the entire operation fails.

In a following example, trying to create a duplicate as part of a transaction that does another valid operation will fail:

TransactionalBatchResponse createDuplicatedShow = await container.CreateTransactionalBatch(new PartitionKey(showName))
    .ReplaceItem<Show>(theShow.Id, theShow)
    .CreateItem<Episode>(Episode.Create(showName, "Cosmos DB SDK Features 2"))
    .ExecuteAsync();

And the TransactionalBatchOperationResult will show that by returning a status of FailedDependency for those items that failed as part of the batch failing:

Batch failed > Show Replace resulted in: FailedDependency
Batch failed > Episode Create resulted in: Conflict