SQL/XML is making good progress
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Not very long ago, we discussed the creation of a new part of SQL, XML-Related Specifications (SQL/XML), in this column [1]. At the time, we referred to the work that had been done as "infrastructure". We are pleased to be able to say that significant progress has been made, and SQL/XML [2] is now going out for the first formal stage of processing, Final Committee Draft (FCD) ballot, in ISO/IEC JTC1.In our previous column, we described the mapping of SQL ⟨identifier⟩s to XML Names, SQL data types to XML Schema data types, and SQL values to XML values. There have been a few small corrections and enhancements in these areas, but for the most part the descriptions in our previous column are still accurate.Thc new work that we will discuss in this column comes in three parts. The first part provides a mapping from a single table, all tables in a schema, or all tables in a catalog to an XML document. The second of these parts includes the creation of an XML data type in SQL and adds functions that create values of this new type. These functions allow a user to produce XML from existing SQL data. Finally, the "infrastructure" work that we described in our previous article included the mapping of SQL's predefined data types to XML Schema data types. This mapping has been extended to include the mapping of domains, distinct types, row types, arrays, and multisets.The FCD ballot that we mentioned began in early April. This will allow the comments contained in the ballot responses to be discussed at the Editing Meeting in September or October of this year. We expect the Editing Meeting to recommend progression to Final Draft International Status (FDIS) ballot, which suggests that an International Standard will be published by the middle of 2003.
[1] Jim Melton,et al. SQL/XML and the SQLX Informal Group of Companies , 2001, SIGMOD Rec..