Clarify error handling in XQuery documentation

Add note about parsing errors and transaction behavior. This was clarified as part of RFC 13225131

Add note about xquery parser error handling

Added note about XQuery parser errors and transaction behavior. This was clarified as part of RFC 13225131

edit

Author: MSFTPawelM

docs/t-sql/xml/guidelines-for-using-xml-data-type-methods.md

@@ -60,6 +60,9 @@ Msg 2396, Level 16, State 1:
 XQuery [xmldb_test.xmlcol.query()]: Attribute may not appear outside of an element
 ```
 
+> [!NOTE]
+> Parsing errors raised by the XQuery parser (such as syntax errors in the XML referenced as part of the XML data type method, for example), abort the active transaction, regardless of the [XACT_ABORT](../statements/set-xact-abort-transact-sql.md) setting of the current session.
+
 ## Singleton Checks
 
 Location steps, function parameters, and operators that require singletons will return an error if the compiler cannot determine whether a singleton is guaranteed at run time. This problem occurs frequently with untyped data. For example, the lookup of an attribute requires a singleton parent element. An ordinal that selects a single parent node is sufficient. The evaluation of a **node()**-**value()** combination to extract attribute values may not require the ordinal specification. This is shown in the next example.

docs/xquery/error-handling-xquery.md

@@ -26,6 +26,9 @@ dev_langs:
  As a deviation from the W3C standard, XQuery run-time errors are converted into empty sequences. These sequences may propagate as empty XML or NULL to the query result, depending upon the invocation context.  
 
  Explicit casting to the correct type allows users to work around static errors, although run-time cast errors will be transformed to empty sequences.  
+
+> [!NOTE]
+> Parsing errors raised by the XQuery parser (such as syntax errors in the XML referenced as part of the XML data type method, for example), abort the active transaction, regardless of the [XACT_ABORT](../t-sql/statements/set-xact-abort-transact-sql.md) setting of the current session.
   
 ## Static Errors  
  Static errors are returned by using the [!INCLUDE[tsql](../includes/tsql-md.md)] error mechanism. In [!INCLUDE[ssNoVersion](../includes/ssnoversion-md.md)], XQuery type errors are returned statically. For more information, see [XQuery and Static Typing](../xquery/xquery-and-static-typing.md).