The input table contains an xml document that has these hierarchical nodes: School at level 1, Dept at level 2, Class at level 3, and Student and Grade at level 4.
| xid | xmldocument |
|---|---|
| 1 | <School name="UCLA"> : <Dept name="EE"> : <Class A="grad" B="undergrad"> : <Student>Harry</Student> : <Grade>A+</Grade> : </Class> : </Dept> : </School> |