NOSQL JSON MODELER CODE

You can see that the way you work with your domain model can be similar to the way you use it in your domain model layer when the infrastructure is EF. Order2 newOrder = GetOrderV2Sample('IdForSalesOrder2') Īwait client.CreateDocumentAsync(collectionUri, newOrder) OrderV2 objects without any changes to the database tier. As your app evolves, let's say your object has a new schema. Uri collectionUri = UriFactory.CreateDocumentCollectionUri(databaseName,Īwait client.CreateDocumentAsync(collectionUri, orderAggregate)

NOSQL JSON MODELER CODE

*** Infrastructure Code using Cosmos DB Client API *** Using methods with domain logic within the entity. logic is consistent across the nested properties (value objects and entities). Then, use AggregateRoot's methods to add the nested objects so invariants and Aggregate: Create an Order object with its child entities and/or value objects. The difference is in the way to use them from the application and infrastructure layers, as in the following code: // C# EXAMPLE OF AN ORDER AGGREGATE BEING PERSISTED WITH AZURE COSMOS DB API When you use a C# model to implement the aggregate to be used by the Azure Cosmos DB API, the aggregate can be similar to the C# POCO classes used with EF Core. It is multi-model and supports document, key-value, graph, and columnar data models.įigure 7-19. Azure Cosmos DB automatically indexes data without requiring you to deal with schema and index management. Azure Cosmos DB provides turn-key global distribution, elastic scaling of throughput and storage worldwide, single-digit millisecond latencies at the 99th percentile, five well-defined consistency levels, and guaranteed high availability, all backed by industry-leading SLAs.

Introduction to Azure Cosmos DB and the native Cosmos DB APIĪzure Cosmos DB is Microsoft's globally distributed database service for mission-critical applications. It is similar to the order aggregate we implemented in the eShopOnContainers sample, but without using EF Core underneath. Then you can include in those 'bags' all the information you might need for that aggregate.įor instance, the following JSON code is a sample implementation of an order aggregate when using a document-oriented database. When you design your domain model based on aggregates, moving to NoSQL and document-oriented databases might be even easier than using a relational database, because the aggregates you design are similar to serialized documents in a document-oriented database. Your domain model can be more flexible than when using a relational database. You really have to design your model with an understanding of how the data is going to be used in each particular database.Ī benefit when using NoSQL databases is that the entities are more denormalized, so you do not set a table mapping. Having the same domain model for relational databases or NoSQL databases is not simple, and you should not try to do it. In a relational database, querying multiple child collection properties is not easily optimized, because you get a UNION ALL SQL statement back from EF. Changing persistence models is not a trivial task, because transactions and persistence operations will be very different.įor example, in a document-oriented database, it is okay for an aggregate root to have multiple child collection properties. There are always constraints and trade-offs in the different database technologies, so you will not be able to have the same model for relational or NoSQL databases.

If you implemented your domain model based on POCO entity classes, agnostic to the infrastructure persistence, it might look like you could move to a different persistence infrastructure, even from relational to NoSQL. The difference is in how you persist that model. When using a NoSQL database, you still are using entity classes and aggregate root classes, but with more flexibility than when using EF Core because the persistence is not relational. However, the use of the database is transparent from a domain model code point of view. When you use a document-oriented database, you implement an aggregate as a single document, serialized in JSON or another format. But, ultimately, the database selection will impact in your design. However, when you use a NoSQL database, especially a document-oriented database like Azure Cosmos DB, CouchDB, or RavenDB, the way you design your model with DDD aggregates is partially similar to how you can do it in EF Core, in regards to the identification of aggregate roots, child entity classes, and value object classes. Instead you use the API provided by the NoSQL engine, such as Azure Cosmos DB, MongoDB, Cassandra, RavenDB, CouchDB, or Azure Storage Tables. When you use NoSQL databases for your infrastructure data tier, you typically do not use an ORM like Entity Framework Core.

Nosql json modeler