Using the clinical trials dataset from the course web site, give XPath queries that return the data requested below:

EXAMPLE QUESTION:

All country elements residing anywhere in the document

EXAMPLE ANSWER:

//country

Q1. The second collaborating agency listed for each study

A1. //clinical_study/sponsors/collaborator[2]/agency


Q2. All enrollment nodes of type "Actual"

A2. //enrollment[@type='Actual']


Q3. The nct_id of each study having a facility located in Toronto

A3. //clinical_study[location//city='Toronto']//nct_id


Q4. For each study having at least one location in Canada, list all
    other countries involved in the study.

A4. //clinical_study[location//country='Canada']/location//country[.!='Canada']


Q5. The condition of each study that discloses at least three
    arm_group elements

A5. //clinical_study[count(arm_group)>2]


Q6. The nct_id and all city names of each study having an
    "Anticipated" enrollment of 250.

A6. //clinical_study[enrollment[.=250]]//*[self::nct_id or self::city]

A6(2.0). //clinical_study[enrollment[.=250]]//(nct_id | city)


Q7. Output the nct_id, last_name of the overall_official, and first
    listed condition for each study with a location in Hershey,
    Pennsylvania, USA.

A7. (//clinical_study[
	location[.//city[.='Hershey'] and .//state[.='Pennsylvania']]
     ]//*[self::nct_id or self::last_name/ancestor::overall_official]
    | //clinical_study[
	location[.//city[.='Hershey'] and .//state[.='Pennsylvania']]
     ]//condition[1]
    )

A7(2.0).  //clinical_study[location[
                .//city[.='Hershey'] and .//state[.='Pennsylvania']]
              ]//(nct_id | overall_official/last_name | condition[1])


Q8. For each study location in Bangkok, give the nct_id of the study,
    the location's facility name, and last name(s) of any investigator
    or contact associated with that location.

A8. ( //clinical_study[location//city[.='Bangkok']]//nct_id
    | //clinical_study/location[.//city[.='Bangkok']]//*[
        self::name/parent::facility
        or self::last_name[parent::investigator or parent::contact]])

A8(2.0). //clinical_study/location[facility//city='Bangkok']/(
                ./ancestor::clinical_study//nct_id
                | facility/name
                | .//(investigator|contact)//last_name)

                
Q9. For each study with at least one location in Germany, output the
    nct_id and -- for each German location in the study -- the
    location name, city, and investigator last_name associated with
    that location. Exclude studies spanning fewer than five locations
    and also exclude any study with a location in Austria.

A9. ( //clinical_study[count(location)>=5
                        and location//country='Germany'
                        and not(location//country='Austria')
                     ]//nct_id
    | //clinical_study[count(location)>=5
                        and location//country='Germany'
                        and not(location//country='Austria')
                     ]/location[.//country='Germany']//*[
                        self::name or self::city
                        or self::last_name/parent::investigator])

A9(2.0). //clinical_study[count(location)>=5
                            and location//country='Germany'
                            and not(location//country='Austria')
               ]/(.//nct_id
                     | location[.//country='Germany']/(
                        .//name
                        | .//city
                        | investigator/last_name))