![]() To better understand what’s happening, take a look at another example. What this points to is that SQL Server handles certain components of an XML fragment-whether converting to or from the XML type-differently from the basic elements, attributes, and their values. XML EntitizationĪs the last example demonstrates, you can use the CONVERT() function to preserve characters that the XML parser normally ignores, such as spaces and tabs between elements. Let’s take a closer look at this process so you can better understand what’s happening behind the scenes when you convert XML data. Now the string includes the tabs and linefeeds as they exist in the original XML fragment. The SELECT statement returns the following results: The way to get around this is to use the CONVERT() function to explicitly cast the string to the XML type, as I do in the following example:Īs you can see, I include a third argument in the CONVERT() function that specifies these elements be preserved. What is essentially happening here is that SQL Server is implicitly converting a string value to the XML type, which means that the tabs and linefeeds are not being preserved during that assignment. Notice that I assign the value simply by setting to equal the XML fragment, enclosed in single quotes. The problem is not with how I convert the value, but with the way I assign the XML fragment to that variable. However, although I take this approach, the value saved to the variable does not preserve these elements, as shown in the results returned by the SELECT statement: However, if you’re running your script only against SQL Server, you can take advantage of the CONVERT() function’s support for additional options, which let you better refine the conversion process.įor instance, in the following example I use tabs between the parent and child elements in the XML fragment:īecause the XML fragment contains these new elements, you might expect that you can simply add the third argument to the CONVERT() function to preserve the tabs and linefeeds. If you want to run your script against another database system, you have to modify your code to conform to that system’s specifications. That’s not the case with the CONVERT() function, which is specific to Transact-SQL in SQL Server. Because the CAST() function conforms to ANSI specifications, you can use it with any database systems that conform to those standards. One reason you might want to use CAST()is if you plan to run your SQL script against a database management system in addition to SQL Server and that system doesn’t support implicit conversions. You might be wondering why you would explicitly cast string or binary data to the XML type if SQL Server handles such conversions implicitly. ![]() Once again, the SELECT statement returns the XML fragment as it is assigned to the variable: Passing XMLType.createXML(SYS.DBMS_XMLGEN.getXML('select name from appname'))īut in this case the conversion to XML is a bit pointless.Notice that I follow the XML data type argument with a comma, then I specify the variable. If you already had the XMLType, or wanted it in that format for some other reason, you could use an XMLQuery instead of extractValue: select xmlquery('/ROWSET/ROW/NAME/text()' Or to 1 (ENTITY_DECODE) to do the reverse operation and decode: select dbms_nvert('Oracle & Database', 1) from dual ĭBMS_XMLGEN.CONVERT('ORACLE& DATABASE',1) The second argument defaults to ENTITY_ENCODE, and you can either set that explicitly (using the underlying value 0 in plain SQL) to encode: select dbms_nvert('Oracle & Database', 0) from dual You're doing more work than you need to dbms_xmlgen has a convert() function, which escapes special characters (entities) by default: select dbms_nvert(name) from appname How can i get this output using DBMS_XMLGEN or is there is any easy way. ![]() Which return back the output same as "Oracle & Database"īut i need output as "Oracle & Database" but it return as "Oracle & Database"īelow is query to transform to XML format select SYS.DBMS_XMLGEN.getXML( 'select NAME from APPName ') XML_out from dualĪnd then i try to extract the Name select extractvalue( XMLType.createXML(SYS.DBMS_XMLGEN.getXML( 'select NAME from APPNAme' )),'/ROWSET/ROW/NAME') XML_out from dual I have used the DBMS_XMLGEN to make it XML Complaint and trying to using extractvalue to get the value. What i need to do is get the output in XML compliant format. I have table name "AppName" select NAME from AppName I need to query a table and display the column value by transforming escape character into XML format
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