Парсинг XML с помощью функционала Oracle SQL

Пример:

with some_table as
(
select '<a><tag at="fcasd"><untag><tag at="svsa">sss</tag></untag></tag></a>' request from dual
union all
select '<a><tag at="dsavA"/><tag at="csa"></tag></a>' request from dual
)
select
st.*,
xml."at"
from
some_table st,
xmltable('//tag' passing xmltype(st.request)
columns "at" varchar2 (20) path '@at') xml;

Источник.