You can normalize this data into SQL tables. For example:
depts – A row for each <dept> element, containing the <dept_id> and <dept_name>.
emps – A row for each <emp> element, containing the <emp_id> and <emp_name>, as well as the <dept_id> element, which contains them.
emp_phones – A row for each <phone>, containing the <phone_no> and the <dept_id> element, which contains all these elements.
projects – A row for each <project>, containing the <project_id> and <budget> elements, and the containing <dept_id> element.