ここでは, XPath処理関数を用いた例をいくつか挙げる.
-- convert XPath to SQL
select xpath2sql('/site/open_auctions/open_auction');
-- above query is equals to
select xpath2sql('/site/open_auctions/open_auction',0);
-- return SQL that extracts ordered flagment
select xpath2sql('/site/open_auctions/open_auction',3);
-- evaluation xpath
select * from xpath_eval('/site/open_auctions/open_auction');
select * from xpath_eval('/site/open_auctions/open_auction',3);
-- evaluation '/PLAY' and set selected node-content "hoge"
UPDATE
xml_node
SET
content = 'hoge'
FROM
xpath_eval('/PLAY') as Q
WHERE
xml_node.id = Q.id;