2.1.4 Data Access

The Conceptual Schema Definition File Format ([MC-CSDL]) describes the structure and semantics of the Conceptual Schema Definition Language (CSDL) for the Entity Data Model (EDM).

The Open Data Protocol (OData) Specification ([MS-ODATA]) depends on HTTP [RFC2616], for transfer of all protocol messages and user data, and follows or extends the messaging semantics defined in AtomPub [RFC5023]. ODATA ([MS-ODATA]) uses the structure defined in [MC-CSDL].

The Entity Data Model for Data Services Packaging Format ([MC-EDMX]) is an XML-based file format that serves as the packaging format for the service metadata of a data service, (as specified in [MS-ODATA]).

The following diagram describes the relationship of Data Access protocols.

Data access protocol relationships

Figure 9: Data access protocol relationships