Gaining the Knowledge of the Open Data Protocol (OData)
Download as PPTX, PDF1 like818 views
This document provides an overview of the Open Data Protocol (OData) and its applications, emphasizing its role in creating and consuming data APIs. It covers foundational concepts of OData, including how to produce and consume feeds, best practices for implementation, and some limitations of the protocol. Additionally, it highlights the importance of OData in enabling data accessibility and management for organizations.
Gaining the Knowledge of the Open Data Protocol (OData)
- 1. GAININGTHE KNOWLEDGEOF THE OPEN DATA PROTOCOL (ODATA) ChrisWoodruff
- 2. WHO I AM? ChrisWoodruff MVP,Visual C# Director at Perficient Co-host of Deep Fried Bytes Podcast @cwoodruff / cwoodruff@live.com Skype: cwoodruff
- 3. YOUWILL LEARN: Understand the background of OData Have an understanding of the OData protocol How to produce an OData feed using WCF Data Services How to produce an OData feed using ASP.NET Web API How to consume an OData feed using LINQ
- 5. QUOTE Today, the tools for capturing data both at the mega-scale and at the milli-scale are just dreadful. After you have captured the data, you need to curate it before you can start doing any kind of data analysis, and we lack good tools for both data curation and data analysis. Jim Gray
- 6. Problem: Data APIs frequently create more problems than solutions THISTALK IS ABOUT ONE SOLUTION.
- 7. SURVEY …knows what the web is …are comfortable w/ HTTP and XML? JSON? …have a basic understanding of the term REST …have created a Data API
- 8. Is there really a problem? What is it? QUIZTIME
- 9. FACEBOOK: WHAT FIELDSWILL I GETWHEN I READ A POST?
- 10. FACEBOOK: HOW DOYOU LIKE A POST?
- 11. How do developers know what to do? SO GIVENTHAT NOBODY KNEWTHE ANSWERSTOTHESE QUESTIONS,
- 12. I GUESSTHEY USE DOCS
- 13. So is there really a problem? Yes DEVELOPERS DON’T HAVETIMETO ACTUALLY READTHE DOCS
- 14. Can OData Magically cure the problem? No, but it can help. LET’S SEE HOW
- 15. THE PROTOCOL Knowledge of OData
- 16. THE BASICS OF ODATA Feeds, which are Collections of typed Entities OData services can expose Actions and Functions (v4), Services (v3) OData services expose all these constructs via URIs OData service may also expose a Service Metadata Document
- 17. FULL SQL LIKE QUERY “LANGUAGE” HTTP Command (Verb) SQL Command GET SELECT PUT UPDATE POST INSERT DELETE DELETE
- 19. CONVENTIONS http://services.odata.org/OData/OData.svc _______________________________________/ | service root URI http://services.odata.org/OData/OData.svc/Category(1)/Products?$top=2&$orderby=name _______________________________________/ __________________/ _________________/ | | | service root URI resource path query options
- 20. URL CONVENTIONS $filter /Suppliers?$filter=Address/City eq 'Redmond‘ $orderby /Products?$orderby=ReleaseDate asc, Rating desc $top and $skip /Products?$top=5&$skip=2 $select and $expand /Products?$select=*,Category/Name&$expand=Category
- 22. PAYLOAD CONVENTIONS Success and error Codes 200 OK, 201 Created, 415 Unsupported MediaType, etc Overall Format JSON AtomPub JSONVerbose Nuances PATCH, Null payloads, etc
- 23. JSON FORMAT Friendly to Javascript 90% more compact than AtomPub Reads like a custom API Very little OData “gunk”
- 24. ATOM FORMAT Atom parsers exist in many frameworks Element fields can be mapped to their Atom counterparts A good example of OData interoperability
- 25. WHAT ELSE CANYOU DO WITH ODATA? Actions and Functions allow hypermedia-based method calls (non-CRUD operations) Defined conventions for PATCH and deep insert Vocabularies
- 26. ODATA ISN’T ALWAYSTHE BEST FIT OData may not be a good fit for highly opinionated APIs laden with developer intent OData may not be a good fit for bulk data transfer OData may not be a good fit for the APIs that dramatically different in shape than the backend
- 27. ODATA DOES NOT SUPPORT ALL QUERIES OData doesn’t currently support aggregation You can’t ask for customers that have at least 2 orders OData doesn’t currently support filters expansions You can’t ask for a customer and only their orders placed in 2013 OData doesn't support “graph” queries You can ask friend-of-a-friend type queries, but there are limitations
- 28. ODATA IS A STANDARD!! OASIS, ISO Ratified in March!
- 29. WHO USES ODATA?
- 30. WHAT DOES ODATA GIVE ME AND MY ORGANIZATION? Empower Internal Power Users Empower Existing and Future Customers Monetize Data for untapped Revenue
- 31. CREATING FEEDW/ ASP.NETWEB API Knowledge of OData
- 33. ODATA BEST PRACTICES (PRODUCER) Always design your OData feed will server-side paging if your entity collections hold large amounts of data. Looks at server-side validation of queries and data updates based on the user credentials sent through HTTP
- 34. CONSUMING ODATA Knowledge of OData
- 35. WHAT IF DATA API’S WERE LIKE… LINQ? What are the last 50 invoices we sent? context.Invoice.OrderByDescending(i=>i.PostedAt).Take(50); What are the invoices from the last 24 hours? context.Invoice.Where(i=>i.PostedAt > DateTime.Now.AddDays(-1)); How many $1M invoices have we sent? context.Invoice.Where(i=>i.TotalAmount >= 1000000);
- 36. ODATA BEST PRACTICES (CONSUMER) Use Query Projection to only bring back the entity properties you or your app needs. Think about client-side paging even if their exists server-side paging. Design and implement a client-side data caching function in your app (unless sensitive data).
- 39. The demo projects can be found at: github.com/cwoodruff/
- 41. CONTACT ME Chris “Woody”Woodruff cwoodruff@live.com Twitter @cwoodruff Skype cwoodruff http://chriswoodruff.com http://deepfriedbytes.com