Thus, the XML document or fragment needs to provide the BOM or other encoding information inline. The content of varbinary is treated as a codepoint stream that is passed directly to the XML parser. Since the varchar source string has a code page associated, the parser will use that code page for the encoding if no explicit encoding is specified in the XML itself If an XML instance has a BOM or an encoding declaration, the BOM or declaration needs to be consistent with the code page, otherwise the parser will report an error. The content of a varchar string is treated as a one-byte encoded XML document/fragment by the XML parser. A UTF-16 encoded XML document can have a UTF-16 byte order mark (BOM), but it doesn't need to, since the context of the source type makes it clear that it can only be a two-byte Unicode encoded document. This means that the XML document needs to be encoded in a two-byte Unicode encoding as well to be compatible with the source data type. Since nvarchar assumes a two-byte unicode encoding such as UTF-16 or UCS-2, the XML parser will treat the string value as a two-byte Unicode encoded XML document or fragment. ![]() The following outlines the rules on how the string and binary source types interact with the XML document encoding and how the parser behaves. XML documents can be encoded with different encodings (for example, UTF-8, UTF-16, Windows-1252). ![]() For more information, see Compare Typed XML to Untyped XML. If there's a schema associated with the xml type, validation is also performed. Untyped XML is checked to confirm that it's well formed. You can parse any of the SQL Server string data types, such as char, text, varbinary,and image, into the xml data type by casting (CAST) or converting (CONVERT) the string to the xml data type. Using the SELECT statement with the FOR XML clause. In SQL Server, you can generate XML instances in the following ways: This article describes how to generate XML instances. Oracle9i XML Database Developer's Guide - Oracle XML DB Release 2 (9.Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance.The following example shows something a little more complex, including a nested query. The XMLCDATA function surrounds column data with a CDATA tag. If you need and XML declaration, you should add it manually to the document. In newer database versions, this function is either deprecated, or removed entirely. The XMLROOT function allows us to place an XML declaration tag at the start of our XML document. Without a root (base) tag, this is not a well formed document, so we must surround it in an XMLELEMENT to provide the root tag. In the following example we can see the three fragments are now presented in a single row. The XMLAGG function allows is to aggregate these separate fragments into a single fragment. We got the XML we wanted, but it is returned as three fragments in three separate rows. What happens if we start dealing with multiple rows of data? So far we have just looked at creating individual XML fragments. Like XMLATTRIBUTES, the XMLFOREST function allows you to process multiple columns at once. Using XMLELEMENT to deal with lots of columns is rather clumsy. XMLATTRIBUTES(e.empno AS "works_number"), The parent XMLELEMENT can contain both attributes and child tags. The attribute names will match the column names using the default uppercase unless an alias is used. The function call should contain one or more columns in a comma separated list. The XMLATRIBUTES function converts column data into attributes of the parent element. The XMLELEMENT function can also be used to group together and place a tag around existing XML fragments. SELECT XMLELEMENT("name", e.ename) AS employee In the following example, the first parameter specifies the tag name to be used and the second specifies the column that will supply the data contained within the tag. The XMLELEMENT function is the basic unit for turning column data into XML fragments. In this article I will only present those I use most frequently. ![]() The SQL/XML functions present in Oracle9i Release 2 allow nested structures to be queried in a standard way with no additionalĭatabase object definitions. This may cause administration problems as the number of database object types will increase drastically as the number of In Oracle 9i Release 1 it was necessary to use several database object types to create complex XML documents using SQL.ĬAST(MULTISET(SELECT e.empno, e.ename, e.job, e.mgr, e.hiredate, e.sal, e.comm The example code in this article assumes you have access to the SCOTT schema.
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