Can we generate the output of SQL Query in XML format ..

Question

Hi Team,
Can we generate an XML doc for an SQL Query.
I've seen in SQL Server 2000.It is generating the output of an SQL Query in xml format.
select * from emp for xml auto
The output looks like
<emp EMPNO="7369" ENAME="SMITH" JOB="CLERK" MGR="7902" HIREDATE="1980-12-17T00:00:00" SAL="2800" DEPTNO="20"/><emp EMPNO="7370" ENAME="SMITH" JOB="CLERK" MGR="7902" HIREDATE="1980-12-17T00:00:00" SAL="2800" DEPTNO="10"/>

Answer 1

Just a little bit of short hand.
Get the XML out of your database, via HTTP
Of course the easiest method is just to return an XMLType from a stored procedure and let the calling routine figure out what to do with it. Instead
of that way though, I'll show you how to do it via HTTP. It's all completely built into 10g and is super easy to use.
CREATE OR REPLACE VIEW emps_and_depts AS
SELECT e.employee_id AS "EmployeeId",
e.last_name AS "Name",
e.job_id AS "Job",
e.manager_id AS "Manager",
e.hire_date AS "HireDate",
e.salary AS "Salary",
e.commission_pct AS "Commission",
XMLFOREST (
d.department_id AS "DeptNo",
d.department_name AS "DeptName",
d.location_id AS "Location"
) AS "Dept"
FROM employees e, departments d
WHERE e.department_id = d.department_id
Some people hear web and immediately start salivating about security issues. Let me address that quickly. Just because you have the HTTP and/or
FTP servers running in the database, that does not mean you have a security problem. For one, I would hope your databases are behind a firewall.
Second, with the correct architecture (DMZ, app servers, etc) you can make this data available outside the firewall fairly transparently and third,
just because it's on the web does not mean the data MUST be available on the internet. This is a good way to make your data available on your
intranet. If you are worried about people INSIDE your firewall, that still doesn't preclude web based access. Follow Oracle security guidelines.
Before I show you how to get to your data, let's talk about URLs and URIs. A URL is a Uniform Resource Locater and URI is a Uniform Resource
Identifier. A URL is the way you would identify a document on the net, i.e. http://www.oracle.com is a URL. A URI is a more generic form of a URL.
Oracle supports three types of URI: HTTPURIType - basically a URL (which would be like the URL above), XDURIType - a pointer to an XDB resource
(usually an XML document but can be other objects), and DBURIType - a pointer to database objects.
It's the DBURIType that we're going to concentrate on here. The DBURIType let's us reference database objects using a file/folder paradigm. The
format for a DBURI is /oradb/<schema>/<table>. Oradb is shorthand for the database; it is not the database name or SID. My database is named XE
but I still use oradb in the DBURI. For example, the view we created above is in my XE database, is owned by HR (at least in my case) and is called
EMPS_AND_DEPTS. This can be referenced as /oradb/HR/EMPS_AND_DEPTS.
If the view had many rows and you wanted only one of them, you can restrict it by including a predicate. The documentation for XDB has a great
write up on Using DBURIs.In our case, we are going to write out the entire document. Now that you understand that the DBURI is a pointer to
objects in our instance, we can use that to access the data as a URL.
The format for the URL call is http://<machinename>:<port>/<DBURI>
In my case, my XE database is running on a machine called mach1 and is listening on port 8080. So to see the view we created above, I open my
browser and navigate to: http//mach1:8080/oradb/HR/EMPS_AND_DEPTS
The created URL will be as http//mach1:8080/oradb/PUBLIC/EMPS_AND_DEPTS
If your database is set up correctly and listening on port 8080 (the default), your browser should ask you to login. Login as the user who created the
view (in my case HR). You should now get an XML document displayed in your browser.
And that's it. It doesn't get much simpler than that. If you get rid of the descriptive text above, it basically comes down to:
Create a table or view
Open your web browser
Enter a URL
Enter a user ID and password
View your XML
If you notice, Oracle formatted the data as XML for us. Our view returns scalar columns and an XML fragment called Dept. Oracle formatted the
return results into an XML format.
And as a side note, if you look closely, you'll see that my URL has PUBLIC where I said to put HR. PUBLIC is a synonym for all objects that your
logged in user can see. That way, if your user has been granted select access on many schemas, you can use PUBLIC and see any of them.