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What is xml
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.
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What is xml
- 1. XML PRESENTATIONExtensionmarkuplanguageBY:SachitSinghhttp://smartpassiveincomes.blogspot.com/
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- 3. Comparison between XMLAND HTML
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- 5. XML QUARIES ANDMEDIATORS
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- 9. http://smartpassiveincomes.blogspot.com/WHAT IS XML XML- Extension markup language
- 10. Markup languagefor document containing structured information
- 11. XML is defineby four specification-
- 12. XML- Extension markuplanguage
- 13. XLL- Extension linklanguage
- 14. XSL- Extension Styleor layout language
- 15. XUA- Extension USERagent http://smartpassiveincomes.blogspot.com/
- 16. XML…..XML is basedon standard generalize markup language (SGML)
- 17. XML Version1.0 introduced by world wide web consortium (W3C) in 1998
- 18. Bridge for dataexchange 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 ElementsAnXML 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 DocumentsAbasic 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 DataIslandsA data island is an XML document that exists within an HTML page.
- 25. The <XML> elementmarks 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 DataIslands (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 asgrammar for the underlying XML document, and it is part of XML language.
- 29. DTDs are somewhatunsatisfactory, but no consensus exists so far beyond the basic DTDs.
- 30. DTD has theform: <!DOCTYPE name [markupdeclaration]>http://smartpassiveincomes.blogspot.com/
- 31. DTD (cont’d)Consider anXML document: <db><person><name>Mithlesh Singh</name> <age>18</age> <email>[email protected] </email> </person> <person>………</person> ………. </db>http://smartpassiveincomes.blogspot.com/
- 32. DTD (cont’d)DTD forit might be: <!DOCTYPE db [ <!ELEMENT db (person*)> <!ELEMENT person (name, age, email)> <!ELEMENT name (#PCDATA)> <!ELEMENT age (#PCDATA)> <!ELEMENT email (#PCDATA)> ]>
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- 34. XML Query LanguagesThefirst 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 Languagefor XML: XML-QLDeveloped at AT&T labs
- 36. To extract datafrom the input XML data
- 37. Has variables towhich data is bound and templates which show how the output XML data is to be constructed
- 38. Uses the XMLsyntax
- 39. Based on awhere/construct syntaxWhere combines from and where parts of SQLConstruct corresponds to SQL’s select
- 40. XML-QL Query: Example1Retrieve 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: Example2XML-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 Dataand MediatorsSemi structured data is often encountered in data exchange and integration
- 43. At the sourcesthe data may be structured (e.g. from relational databases)
- 44. We model thedata as semi structured to facilitate exchange and integration
- 45. Users see anintegrated semi structured view that they can query
- 46. Queries are eventuallyreformulated into queries over the structured resources (e.g. SQL)
- 47. Only results needto 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:Dataconversion: 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 Databaseto 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 Databaseto XML (Cont’d)XML: <store> <name> … </name> <phone> … </phone> <book> <title>… </title> <authors> … </authors> <price> … </price> </book> <book>…</book> … </store>
- 51. Limitation of HTMLLimitationsof 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
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- 53. Comparisons of XMLAND HTML
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- 55. Authoring XML Elements(cont’d)
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- 57. Authoring XML Documents(cont’d)
- 58. And many more……THANKYOUTHANKS FOR HEARING ME http://smartpassiveincomes.blogspot.com/