Subject: Distributed Database

Topic: XML

Difficulty: High

Give the DTD for an XML representation of the following nested relational schema.

Emp =(ename, childrenset setoff(children),skillset setoff(skills))

Children=( name, birthday)

Birthday =( day, month ,year)

Skills=( type,examset setoff(exams))

Exams=( year, city)

<! DOCTYPE Emp [
<!ELEMENT Emp(ename,children*,skills*)>
<!ELEMENT children(name,birthday)>
<!ELEMENT birthday(day, month,year)>
<!ELEMENT skills(type,exams+)>
<!ELEMENT exams(year,city)>
<!ELEMENT ename(#PCDATA)>
<!ELEMENT name(#PCDATA)>
<!ELEMENT day(#PCDATA)>
<!ELEMENT month(#PCDATA)>
<!ELEMENTS year(#PCDATA)>
<!ELEMENTS type(#PCDATA)>
<!ELEMENTS city(#PCDATA)>
]>