A Comments on xpath

hi w3c,
 I am a software engineer, and I like xpath very march, It(xpath) facilitate my
work very march. But I feeled very surprise why there are not other operation in
xpath,such as update/remove/add which are used wide.I advise you to  introduce
other operation ,such as update/remove/add, to xpath, and make xpath operateing
xml like SQL operateing relate table.

best regards

wookland