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The main aim of OData is to define an abstract data model and a protocol which, combined, enable any client to
access data exposed by any data source. Clients might include Web browsers, mobile devices, businessintelligence
tools, and custom applications (for example, written in programming languages such as PHP or Java);
data sources can include databases, content-management systems, the Cloud, or custom applications (for
example, written in Java).
The OData approach to data exchange involves the following elements:
● OData data model
Provides a generic way to organize and describe data. OData uses the Entity 1 Data Model (EDM).
● OData protocol
Enables a client to query an OData service. The OData protocol is a set of interactions, which includes the
usual REST-based create, read, update, and delete operations along with an OData-defined query language.
The OData service sends data in either of the following ways:
○ XML-based format defined by Atom/AtomPub
○ JavaScript Object Notation (JSON)
● OData client libraries
Enables access to data via the OData protocol. Since most OData clients are applications, pre-built libraries
for making OData requests and getting results reduces and simplifies work for the developers who create
those applications.
A broad selection of OData client libraries are already widely available, for example: Android, Java, JavaScript,
PHP, Ruby, and the best known mobile platforms.
● OData services
Exposes an end point that allows access to data in the SAP HANA database. The OData service implements
the OData protocol (using the OData Data Services runtime) and uses the Data Access layer to map data
between its underlying form (database tables, spreadsheet lists, and so on) and a format that the requesting
client can understand.
8.1.2 OData Service Definitions
The OData service definition is the mechanism you use to define what data to expose with OData, how, and to
whom. Data exposed as an OData collection is available for analysis and display by client applications, for
example, a browser that uses functions provided by an OData client library running on the client system.
To expose information by means of OData to applications using SAP HANA XS, you must define database views
that provide the data with the required granularity. Then you create an OData service definition, which is a file you
use to specify which database views or tables are exposed as OData collections.
Note: SAP HANA XS currently supports OData version 2.0, which you can use to send OData queries
(using the http GET method). Language encoding is restricted to UTF-8.
An OData service for SAP HANA XS is defined in a text file with the file suffix .xsodata, for example,
OdataSrvDef.xsodata. The file must contain at least the entry service {}, which would generate a
completely operational OData service with an empty service catalog and an empty metadata file. However, usually
you use the service definition to expose objects in the database catalog, for example: tables, SQL views, or
calculation rules.
In the OData service-definition file, you can use the following ways to name the SAP HANA objects you want to
expose by OData:
● Repository objects
SAP HANA Developer Guide
Defining Web-based Data Access
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