What is xml
Download as PPTX, PDF0 likes847 views
The document discusses XML (eXtensible Markup Language), including a comparison between XML and HTML, how to author XML elements and documents, XML data islands, document type definitions (DTDs), XML query languages like XML-QL, mediators, limitations of HTML, and challenges with XML. It provides examples of XML syntax as well as XML-QL queries to retrieve author names and bookstore names.
What is xml
- 1. XML PRESENTATIONExtensionmarkuplanguageBY:Sachit Singhhttp://smartpassiveincomes.blogspot.com/
- 3. Comparison between XML AND HTML
- 4. XML SYNTAX
- 5. XML QUARIES AND MEDIATORS
- 7. Challenges
- 8. Summery
- 9. http://smartpassiveincomes.blogspot.com/WHAT IS XML XML- Extension markup language
- 10. Markup language for document containing structured information
- 11. XML is define by four specification-
- 12. XML- Extension markup language
- 13. XLL- Extension link language
- 14. XSL- Extension Style or layout language
- 15. XUA- Extension USER agent http://smartpassiveincomes.blogspot.com/
- 16. XML…..XML is based on standard generalize markup language (SGML)
- 17. XML Version 1.0 introduced by world wide web consortium (W3C) in 1998
- 18. Bridge for data exchange on the web http://smartpassiveincomes.blogspot.com/
- 19. XML Extensible set of tagsContent orientedStandard data infrastructureAllows multiple output formsHTMLFixed set of tagsPresentation orientedNo data validation capabilitySingle presentationComparison http://smartpassiveincomes.blogspot.com/
- 20. Authoring XML ElementsAn XML element is made up of a start tag, an end tag, and data in between.Example: <director> Prabhu Deva </director>Example of another element with the same value: <actor> Salman Khan </actor>XML tags are case-sensitive: <CITY> <City> <city>XML can abbreviate empty elementsfor example: <married> </married> can be abbreviated to <married/>http://smartpassiveincomes.blogspot.com/
- 21. Authoring XML Elements (cont’d)An attribute is a name-value pair separated by an equal sign (=).Example: <City ZIP=“400097”> Malad</City>Attributes are used to attach additional, secondary information to an element.http://smartpassiveincomes.blogspot.com/
- 22. Authoring XML DocumentsA basic XML document is an XML element that can, but might not, include nested XML elements.Example: <books> <book isbn=“123”> <title> C++ </title> <author> Bal Guru Swami </author> </book> </books>http://smartpassiveincomes.blogspot.com/
- 23. Authoring XML Documents (cont’d)Authoring guidelines:All elements must have an end tag.All elements must be cleanly nested (overlapping elements are not allowed).All attribute values must be enclosed in quotation marks.Each document must have a unique first element, the root node.http://smartpassiveincomes.blogspot.com/
- 24. Authoring XML Data IslandsA data island is an XML document that exists within an HTML page.
- 25. The <XML> element marks the beginning of the data island, and its ID attribute provides a name that you can use to reference the data island.http://smartpassiveincomes.blogspot.com/
- 26. Authoring XML Data Islands (cont’d)Example: <XML ID=“XMLID”> <customer> <name> Mithlesh Singh</name> <custID> 12345 </custID> </customer> </XML>http://smartpassiveincomes.blogspot.com/
- 27. Document Type Definitions (DTD)An XML document may have an optional DTD.
- 28. DTD serves as grammar for the underlying XML document, and it is part of XML language.
- 29. DTDs are somewhat unsatisfactory, but no consensus exists so far beyond the basic DTDs.
- 30. DTD has the form: <!DOCTYPE name [markupdeclaration]>http://smartpassiveincomes.blogspot.com/
- 31. DTD (cont’d)Consider an XML document: <db><person><name>Mithlesh Singh</name> <age>18</age> <email>mith@gmail.com </email> </person> <person>………</person> ………. </db>http://smartpassiveincomes.blogspot.com/
- 32. DTD (cont’d)DTD for it might be: <!DOCTYPE db [ <!ELEMENT db (person*)> <!ELEMENT person (name, age, email)> <!ELEMENT name (#PCDATA)> <!ELEMENT age (#PCDATA)> <!ELEMENT email (#PCDATA)> ]>
- 34. XML Query LanguagesThe first XML query languagesLOREL (Stanford)XQLSeveral other query languages have been developed (e.g. UNQL, XPath)XML-QL considered by W3C for standardizationCurrently W3C is considering and working on a new query language: XQueryhttp://smartpassiveincomes.blogspot.com/
- 35. A Query Language for XML: XML-QLDeveloped at AT&T labs
- 36. To extract data from the input XML data
- 37. Has variables to which data is bound and templates which show how the output XML data is to be constructed
- 38. Uses the XML syntax
- 39. Based on a where/construct syntaxWhere combines from and where parts of SQLConstruct corresponds to SQL’s select
- 40. XML-QL Query: Example 1Retrieve all authors of books published by Bal guru swami: where <book> <publisher><name> Bal Guru Swami </name> </publisher> <title> $T </title> <author> $A </author> </book> in “www.a.b.c/abc.xml” construct <result> $A </result>
- 41. XML-QL Query: Example 2XML-QL query asking for all bookstores that sell The C++ Programming Language for under $25:where <store> <name> $N </name> <book> <title> The C++ Programming Language </title> <price> $P </price> </book> </store> in “www.store/abc.xml” $P < 25construct <result> $N </result>
- 42. Semi structured Data and MediatorsSemi structured data is often encountered in data exchange and integration
- 43. At the sources the data may be structured (e.g. from relational databases)
- 44. We model the data as semi structured to facilitate exchange and integration
- 45. Users see an integrated semi structured view that they can query
- 46. Queries are eventually reformulated into queries over the structured resources (e.g. SQL)
- 47. Only results need to be materializedWhat is a mediator ?A complex software component that integrates and transforms data from one or several sources using a declarative specification
- 48. Two main contexts:Data conversion: converts data between two different modelse.g. by translating data from a relational database into XMLData integration: integrates data from different sources into a common view
- 49. pricestockStoreBookStoreBookauthorsnamebidphonetitlesidConverting Relational Database to XMLExample: Export the following data into XML and group books by storeRelational Database: Store (sid, name, phone) Book (bid, title, authors)StoreBook (sid, bid, price, stock)
- 50. Converting Relational Database to XML (Cont’d)XML: <store> <name> … </name> <phone> … </phone> <book> <title>… </title> <authors> … </authors> <price> … </price> </book> <book>…</book> … </store>
- 51. Limitation of HTMLLimitations of HTML – Structure of data expressed as layout – Semantics of data hard to analyze and difficult to share – No schemas, no constraints Thus XML (extensible Markup Language) has been developed – Markup language to define structured documents – Document schemas to fix the structure of documents – User-defined markup to express semantics – XML architecture for processing and extended functionality
- 53. Comparisons of XML AND HTML
- 55. Authoring XML Elements (cont’d)
- 57. Authoring XML Documents (cont’d)
- 58. And many more……THANK YOUTHANKS FOR HEARING ME http://smartpassiveincomes.blogspot.com/