\nI answered a question on the beta newsgroups last week about OSD and RSD (remember them?) by saying that those features had been pushed out into the future. The person then asked if the material in chapter 14 of our first look book had any practical value. I must admit that you can't cut and paste the examples and run them in the upcoming release. I don't know anything concrete about feature futures yet, so here's the long answer… from last week.\n<\/p>\n
\nThe features in chapter 13 and 14 were postponed, so they may appear in
\nfuture implementations. I used to tell folks those chapters are "very
\nfuturistic". \ud83d\ude09 They may not appear line-for-line, class-for-class, the way
\nI coded them. But let's see where they are today without guessing at future.\n<\/p>\n
\nObjectSpaces was moved to the WinFS group. AFAIK (blogs and official notice)
\nit may not appear in WinFS as exactly the same implementation. In the last
\nWinFS public beta, OPath was\/is the WinFS query language. Can't say what the
\nstatus of it all is today. There is no OSD or RSD in .NET 2.0.\n<\/p>\n
\nObject-relational mapping as a concept has been around since there were
\nrelational databases and object-oriented programming. Whether
\ncodification\/generalization of it into a product is a good idea is a subject
\nof *endless* debate, which I *don't* want to start again here. Some of the
\nproducts, past and present, have suffered from performance issues. But the
\nfact remains that if you are using relational data and object classes on the
\nclient to consume\/format\/present that data, you are likely doing
\nobject-relational transformation (even if it is very shallow) to some
\nextent.\n<\/p>\n
\nSystem.Xml.Serialization is the preferred codification of XML-object mapping
\nin the .NET framework today. There is also the implementation in
\nSystem.Remoting.\n<\/p>\n
\nThe concept and implementation of a "query-intermediate language" mentioned
\nin chapter 13 was used in .NET 2.0 in XmlCompiledTransform class.
\nClient-side XQuery in .NET 2.0 was postponed because the spec is not
\nfinished yet. Many implementations of XML consumers use a single library to
\npermit XPath\/XSLT\/XQuery in the same exe, probably don't use the
\nintermediate language concept, but use something coneptually similar. There
\nis no XSD\/RSD mapping in .NET 2.0.\n<\/p>\n
\nXML-relational mapping is in SQL Server 2005 in the guise of:
\n1. SELECT … FOR XML
\n2. OpenXml and xml.nodes
\n3. SQLXML4 (which is part of SQL Server 2005)
\n4. SQLXML3 (which is still supported)
\n5. XML Web Services\n<\/p>\n
\nThere is an ISO\/ANSI spec SQL2003 part 14, that codifies some\/most\/all of
\nthese mapping concepts. In addition to SQL Server's implementation (in 2000
\nand 2005) other databases have similar but different ways of approaching
\nthis problem.\n<\/p>\n
\nSo the class names, product\/feature names, and implementation may change,
\nbut the concepts and data models remain the same. As does the use of
\nmultiple data models in the same programming project.\n<\/p>\n
\nHope this helps.<\/p>\n","protected":false},"excerpt":{"rendered":"
I answered a question on the beta newsgroups last week about OSD and RSD (remember them?) by saying that those features had been pushed out into the future. The person then asked if the material in chapter 14 of our first look book had any practical value. I must admit that you can't cut and paste the examples and […]<\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[],"class_list":["post-924","post","type-post","status-publish","format-standard","hentry","category-data-access"],"yoast_head":"\n