在DB2脚本中将SQL查询结果导出为XML

Question

I'm trying to query a lot of system/database information in an SQL script to be run on DB2 Linux/Unix/Windows. Ideally the output should be both machine readable and at least somewhat comprehensible for humans.

As formatting the output in DB2 CLP seems erratic (or I'm too newb) I tried to output stuff as XML and process it later on, something like:

VALUES ('<?xml version="1.0"?>');
SELECT REC2XML(1.0, 'COLATTVAL', 'row', NAME, VALUE, DEFERRED_VALUE) FROM SYSIBMADM.DBMCFG ORDER BY NAME;

This works ok; I get output I can probably process further.

However, when I try to run REC2XML with a function such as current_timestamp:

SELECT Current_timestamp FROM sysibm.sysdummy1;

I can't use REC2XML as that only seems to support column selects.

Not having much DB2 knowledge:

1. Is there a better/easier way to generate XML output from an SQL script
2. Is there some way to also output the results of functions such as current_timestamp as XML?

Note that I'm after an SQL script (not a shell script); if possible I would like to keep it usable on Windows, Linux and Unix machines...

Answer 1

1. I don't know of a better way.

2. You can get XML output of functions like this:

    Select REC2XML(1.0, 'COLATTVAL', 'row', ct) From (SELECT current timestamp as ct FROM sysibm.sysdummy1); 

Answer 2

This function does not exist in DB2 for zOS. The alternate is to use XMLFOREST to generate a column set and XMLAGG to merge the rows.

SELECT
xmlserialize(
    xmlelement(
        name "employees",
        xmlagg(
            xmlelement(
                name "employee",
                xmlforest(
                    EMPNO as "empno",
                    SURNAME as "surname",
                    MIDNAME as "midname",
                    FIRSTNAME as "firstname",
                    HIREDATE as "hiredate"
                )
            )   
            order by EMPNO
        )
    AS CLOB VERSION '1.0' INCLUDING XMLDECLARATION
    )
)
from EMPLOYEES

Sample:

<?xml version="1.0" encoding="UTF-8"?><employees><employee><empno>12345</empno> ...