XML enhancements in 15.0 include XML schema support, for xml clause enhancements, and Unicode (I18N) support.
You can validate XML documents against either a DTD or an XML schema. The DTD or schema can be specified either in the xmlvalidate command or in the document itself.
You can parse, store, and query XML documents with XML schema declarations.
In Transact-SQL, an expression subquery is a parenthesized subquery. It has a single column, the value of which is the expression subquery result, and must return a single row. You can use an expression subquery almost anywhere you can use an expression.
For more information about subqueries, see the Transact-SQL® User’s Guide.The for xml subqueries feature allows you to use any subquery containing a for xml clause as an expression subquery. For the syntax of for xml subqueries, see the XML Services Guide.
The I18N extensions fall into three categories:
I18N support in the for xml clause. The columns of the result set you map to XML can contain non-ASCII data.Such data can be represented in the generated SQLX XML document either as plain characters or as numeric character representations (NCRs).
I18N in xmlparse and xmlvalidate, to store and validate documents containing non-ASCII data.
I18N in xmlextract and xmltest, to process XML documents and queries containing non-ASCII data.