Oracle XMLTABLE and XPATH - sql

Question

I'm a bit lost with Xpath, I'm trying to get attributes from a XML, I'm currently using :
XMLTABLE('/attrs/attr[#name="ImagesWEB"]/string'
PASSING XMLTYPE(XML)
COLUMNS IMAGESWEB VARCHAR2(100) PATH '.'
)
But I need to get an other value with attribute name Image2, so I did an other XMLTABLE but I guess it's not the right way to do it, I have to use XMLTABLE('/attrs/attr'... with two columns, but don't know how can I get both (Image2 can be missing form the XML data) form XPATH ?
Here an XML example (coming for my product's CLOB) :
<attrs>
<attr multiple="true" name="Image2">
<string>IMG2.PNG</string>
<string>IMG3.PNG</string>
<string>IMG4</string>
</attr>
<attr multiple="true" name="ImagesWEB">
<string>IMG.PNG</string>
</attr>
<attr name="ShortLink">
<string>/PRODUCT.html</string>
</attr>
<attr name="TITRE">
<string>TITLE</string>
</attr>
<attr name="name">
<string>PRODUCT</string>
</attr>
</attrs>
Thansk!

Answer 1

You can change your main XPath to just get the attrs, and then filter which you want in the Xpath for each columns clause:
XMLTABLE('/attrs'
PASSING XMLTYPE(XML)
COLUMNS
IMAGESWEB VARCHAR2(100) PATH 'attr[#name="ImagesWEB"]/string',
IMAGE2 VARCHAR2(100) PATH 'attr[#name="Image2"]/string'
)
db<>fiddle with some made-up data.
But what if I have two values (it might happen) ?
If you can have multiple string nodes under an attribute then you can get both attr nodes from one XMLTable call, and then have two more - one for each attr - to get the strings:
SELECT t.id, x2.imagesweb, x3.image2
FROM your_table t
CROSS APPLY
XMLTABLE('/attrs'
PASSING XMLTYPE(t.XML)
COLUMNS
IMAGESWEB XMLTYPE PATH 'attr[#name="ImagesWEB"]',
IMAGE2 XMLTYPE PATH 'attr[#name="Image2"]'
) x1
OUTER APPLY
XMLTABLE('/attr/string'
PASSING x1.imagesweb
COLUMNS
IMAGESWEB VARCHAR2(100) PATH '.'
) x2
OUTER APPLY
XMLTABLE('/attr/string'
PASSING x1.image2
COLUMNS
IMAGE2 VARCHAR2(100) PATH '.'
) x3
ID IMAGESWEB IMAGE2
-- --------- ----------
1 ABC DEF
2 ABC
3 DEF
3 DEF2
4 IMG.PNG IMG2.PNG
4 IMG.PNG IMG3.PNG
4 IMG.PNG IMG4
db<>fiddle with mix of made-up and sample data.
This uses cross apply and outer apply (because one or the other attribute might not exist), which are available from Oracle 12c (12.1.0.1).