Laurent Schneider

I wrote about powershell [xml] yesterady : xml and powershell

Let’s see how to use XPATH expressions in Powershell

<emplist>
  <emp no="1">
    <ename>John</ename>
  </emp>
  <emp no="2">
    <ename>Jack</ename>
  </emp>
</emplist>

With the [xml] datatype, we create a navigator :

(([xml](GC foo.xml)).psbase.createnavigator().evaluate(
'//emplist/emp[@no="1"]/ename/text()'
))|%{$_.Value}

John

I have not been seduced by a Microsoft product since ages, but I must say I felt with love in this goody much more than in perl, cygwin, or whatever python, dos, java, vb…

It is simply great to use on the command line and can do my work.

1:0 for Microsoft

I wrote about the unix command-line utility xmllint there : extract xml from the command line

Let’s do the same exercice in Powershell

PS> gc foo.xml
<emplist>
  <emp no="1">
    <ename>John</ename>
  </emp>
  <emp no="2">
    <ename>Jack</ename>
  </emp>
</emplist>

Simply use [xml] datatype !

(([xml](GC foo.xml)).emplist.emp|Where{$_.no-eq"1"}).ename
John

Powershell rules!

I just discovered this morning this cool utility in my /bin directory : xmllint

You can use it to extract values from your xml files within your shell scripts

$ cat foo.xml
<emplist>
  <emp no="1">
    <ename>John</ename>
  </emp>
  <emp no="2">
    <ename>Jack</ename>
  </emp>
</emplist>
$ echo 'cat //emplist/emp[@no="1"]/ename/text()'|
  xmllint --shell foo.xml |
  sed -n 3p
John

I like this !

This is asked over and over in the forums, but why not proposing an 11g solution here

create table t(description varchar2(12) primary key, 
  numbers varchar2(4000));
insert into t(description, numbers) values ('PRIME','2,3,5,7');
insert into t(description, numbers) values ('ODD','1,3,5,7,9');
commit;

Now I want to unpivot numbers in rows

select description,(column_value).getnumberval()  
from t,xmltable(numbers)

It is that simple

Works also with strings :

select (column_value).getstringval() 
from xmltable('"a","b","c"');

Yesterday I had my first session about XML, today I have one about SQL Model

Ok, it was the first time I spoke about XML so I did not really now where to focus. XML is so big, you have XQUERY, XPATH, dozens of XML functions in the database.

One of the XML function is called XMLTRANSFORM and transforms XML according to XSLT

I had a fun demo about XSLT to create a semi-column separated list :

select
   deptno,
   xmltransform
   (
      sys_xmlagg
      (
         sys_xmlgen(ename)
      ),
     xmltype
     (
       '<?xml version="1.0"?><xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
          <xsl:template match="/">
            <xsl:for-each select="/ROWSET/ENAME">
              <xsl:value-of select="text()"/>;</xsl:for-each>
          </xsl:template>
        </xsl:stylesheet>'
     )
  ).getstringval() listagg
from emp
group by deptno;

 DEPTNO LISTAGG
------- --------------------------------------
     10 CLARK;KING;MILLER;
     20 SMITH;FORD;ADAMS;SCOTT;JONES;
     30 ALLEN;BLAKE;MARTIN;TURNER;JAMES;WARD;