OData Notes
What is OData?
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OData is an acronym for “Open Data Protocol”.
Develop services with the high levels of data integration and cross-platform interoperability.
Since the protocol is HTTP based, any programming language with HTTP stack can be used for consuming OData
services.
What is SAP NetWeaver Gateway?
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Window for outside world to peep into SAP and transfer data to/from SAP.
Outer world can send HTTP(s) message and SAP would provide them with OData.
Technology that seamlessly connects devices, platforms and environments to SAP Enterprise Data using the
OData services.
Client-Server Architecture - Concept
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Client and Server Components can be developed independently.
Client has no part in data storage, manipulation, etc.
Server has no part in data presentation.
Stateless - What does it mean?
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Every single HTTP request that is received by the Server is forgotten after a response is sent.
Server holds no information about state of session on client.
Servers do not remember or recall the previous request.
What is RESTful?
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REST = REpresentational State Transfer.
Architectural Style - Uses simple and lightweight mechanism for inter-machine communication.
Resource based unlike RPC or SOAP which are Action based.
An interface can be called RESTful if it satisfies the below 6 Guiding Constraints:
1. Client-Server
2. Stateless
3. Cacheable
4. Uniform Interface
5. Layered System
6. Code on Demand (optional)
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Source: ZAP Yard
How does OData Technology Help Developers?
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Implemented using XML or JSON
o both are well known, plain text protocols.
OData message is self-describing
o non-SAP Web developer can understand the content of the OData message without the knowledge of ABAP
or how SAP works.
Segregation of Duties
o Backend Developers and Front-End Developers can work independently.
o No need to depend on one team for the completion of the development.
Why is OData called ODBC of Web?
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OData offers Database-like access to Server-side resources.
ODBC (Open DataBase Connectivity) is standard API to access DBMS, independent of DBMS or OS.
ODBC achieves this by adding drivers between the Application Layer and DBMS to translate queries requested
by the Applications into instructions which DBMS understands.
Similarly, OData acts like middleware between Consumers and Producers (SAP or non-SAP OData).
OData in SAP - What was the need?
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OData was originally created by Microsoft. Earlier a Point-to-Point solution was designed for building an
interface with any Microsoft product be it browser, mobile device, or OS. This was not only time consuming but
was also redundant.
So, the alternative to Point-to-Point solution was 1 Data Model => 1 API => Multiple End-User Experience.
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Source: ZAP Yard