Types CDS views and concepts

SAP CDS views (Core Data Services views) are a powerful way to model and define data structures in SAP systems like S/4HANA. They offer a SQL-like syntax with enhancements for defining data models, relationships, and annotations. Here's a breakdown of CDS views and their types:

Key Features of CDS Views:

• Annotations: CDS views use annotations to define properties like data types, field labels, and associations between entities. This makes them more readable and maintainable than traditional database views.
• Data Modeling: They support concepts like entities, associations, and inheritance, enabling you to build complex data models that accurately represent your business data.
• Performance Optimization: CDS views are optimized for performance, especially when used with SAP HANA. They can leverage the in-memory capabilities of HANA for fast data processing.
• Extensibility: You can extend existing CDS views without modifying the original definition, promoting reusability and reducing development effort.
• OData Integration: CDS views can be easily exposed as OData services, making them ideal for building modern applications and APIs.

Types of CDS Views:

• Basic Views: These are the simplest type. They define a view on a single database table or another CDS view. They typically select fields and can include simple calculations or filters.

  define view Z_Basic_Product_View as select from I_Product {      key Product,      ProductName,      ProductPrice  }  

• Composite Views: These combine data from multiple basic views or tables. They use joins to link related data and can include more complex logic and calculations.

  define view Z_Composite_Sales_View as select from Z_Basic_Product_View      join I_SalesOrder on Z_Basic_Product_View.Product = I_SalesOrder.Product {          Z_Basic_Product_View.ProductName,          I_SalesOrder.OrderID,          I_SalesOrder.NetAmount  }  

• Consumption Views: These are designed for analytical reporting and consumption by tools like SAP Analytics Cloud. They often include aggregations, calculated measures, and annotations for analytical properties.

  define view Z_Consumption_Sales_Analysis as select from Z_Composite_Sales_View {      key Z_Composite_Sales_View.ProductName,      sum(I_SalesOrder.NetAmount) as TotalSalesAmount  } annotation {      @Analytics.query: true  }  

• Extension Views: These extend existing CDS views by adding fields, calculations, or filters without modifying the original view. This allows you to customize standard views without affecting upgrades.

  extend view I_Product with Z_Product_Extension {      @UI.hidden: true      LastUpdatedDate  }  

Benefits of using CDS Views:

• Simplified Data Access: CDS views provide a single point of access to data from multiple tables, making it easier to retrieve and work with.
• Improved Code Readability: The declarative syntax and annotations make CDS views more readable and easier to understand than traditional ABAP code.
• Enhanced Performance: CDS views can be optimized for performance by leveraging the capabilities of SAP HANA.
• Increased Reusability: CDS views can be reused across different applications and reports, reducing development effort.
• Simplified OData Exposure: CDS views can be easily exposed as OData services for consumption by external applications.

By understanding the different types of CDS views and their capabilities, you can effectively model your business data and build efficient and scalable applications in SAP.