CSE 344 Homework 4

Objectives:
To be able to manipulate XML: query it with XQuery.
Reading Assignments:
Lecture notes on XML and XQuery.
Number of points:
100, 10 for each sub-question.
Due date:
Wednesday, April 27th, 2011 - 11:59 pm
Turn in format:
Turn in your queries in 9 separate XQuery files, where each file is named "Problem[problem #].xq". For example, the solution to problem 1 would be saved in "Problem1.xq". You will also need to turn in your resulting html file for problem 8, call it "Problem8.html". The header of each XQuery file (commented) should contain your name and course. Below the XQuery, in a comment, should be the first 3 items it returned (if there are fewer than 3, list them all). XQuery comments look like (: this :). For example, the first question is: (1) Retrieve all the names of all cities located in Peru, sorted alphabetically.

Your file should contain 
      (: Name
         CSEP 544
         Other metadata...
      :)

      (: Problem 1. :)

      (Insert your XQuery here)

      (: Results
          <result>
              <country>
                  <name>Peru</name>

                  <city>
                      <name>Abancay</name>
                  </city>
                  <city>
                      <name>Arequipa</name>

                  </city>
                  <city>
                      <name>Ayacucho</name>
                  </city>
                  ...
              </country>

          </result>
      :)
We should be able to run your XQuery files for any of the problems and place the results into a separate file that can be run to verify your solution. For instance, if your answer to problem X is placed in file ProblemX.xq and the following command is run,
java -cp saxon9he.jar net.sf.saxon.Query ProblemX.xq
the correct query result for problem X should be printed to standard output.
 
Turn in link:
Please turn in your assignment in the dropbox.
Assignment Tools:
XQuery via Saxon (which has both Java and .NET version).
  1. Please first install saxon on your pc (Saxon Java version only requires unzipping the jar file).
  2. Download Mondial XML dataset and Mondial DTD from here.
  3. Follow the brief tutorial to get started (Saxon with Java+Linux).
References:

Problems

[100 points, 10 pts for each sub-question (8 pts for correct answer, 2 pts for following the DTD) and 10 pts for the correct HTML file in problem 8] Consider the XML data instance Mondial, available here (about 1.8 MB). Write XQueries to answer the following questions. In formulating your questions, you need to understand how various elements are nested: e.g. what is under a country, under which element is a city etc. For that it helps if you inspect the Mondial DTD (ignore the warning that the data is not valid), or inspect the data directly.

Moreover, the output of the xquery should follow the associated DTD provided after each question. We will inspect visually if your output follows the DTD, except for problem 9, where we will validate your output automatically. Furthermore, the output of each xquery should be a well formed XML after standard XML headers (<?xml version="1.0" encoding="UTF-8" ?>, etc) have been added. That is, the output of the first question should be (along the lines of): 

    <result>
        <country>
            <name>Peru</name>

            <city>
                <name>Abancay</name>
            </city>
            <city>
                <name>Arequipa</name>

            </city>
            <city>
                <name>Ayacucho</name>
            </city>
            ...
        </country>

    </result>
Note: The amount of white space does not matter.

To test your results to ensure that they are well-formed or that they follow the appropriate DTD, you can use the w3 markup validator. Instructions for how to use this validator are provided here. You must perform this validation for problem 9, the others are optional.

  1. Retrieve all the names of all cities located in Peru, sorted alphabetically. 
    <!ELEMENT result (country)>
<!ELEMENT country (name, city+)>
<!ELEMENT city (name)>
<!ELEMENT name (#PCDATA)>
  2. For each province of China, return its capital. Order the result by province name. 
    <!ELEMENT result (country)>
<!ELEMENT country (name, province+)>
<!ELEMENT province (name, capital)>
<!ELEMENT capital (name)>
<!ELEMENT name (#PCDATA)>
  3. Find all countries with more than 20 provinces. Order by the number of provinces. 
    <!ELEMENT result (country*)>
<!ELEMENT country (name)>
<!ATTLIST country num_provinces CDATA #REQUIRED>
<!ELEMENT name (#PCDATA)>
  4. For each province(state) in the United States, compute the ratio of its population to area, and return each province's name, its computed ratio, and order them by ratio. 
    <!ELEMENT result (country)>
<!ELEMENT country (name, state+)>
<!ELEMENT state (name, population_density)>
<!ELEMENT name (#PCDATA)>
<!ELEMENT population_density (#PCDATA)>
  5. Find all ethnic groups that live in more than 10 countries. 
    <!ELEMENT result (ethnicgroups+)>
<!ELEMENT ethnicgroups (name)>
<!ATTLIST ethnicgroups num_countries CDATA #REQUIRED>
<!ELEMENT name (#PCDATA)>
  6. Find all the provinces(states) of the United States with population more than 11,000,000. Compute the ratio of each qualified state's population to the whole population of the country. Return each state's name and the ratio. Order by the ratio in descending order. 
    <!ELEMENT result (country)>
<!ELEMENT country (name, state+)>
<!ELEMENT state (name, population_ratio)>
<!ELEMENT name (#PCDATA)>
<!ELEMENT population_ratio (#PCDATA)>
  7. Find the names of all countries that have at least 3 mountains over 2000m high, and list the names and heights of all mountains in these countries (regardless of their height). Note: the height attribute is in meters, so you don't have to do any conversions. 
    <!ELEMENT result (country+)>
<!ELEMENT country (name, mountains+)>
<!ELEMENT mountains (name, height)>
<!ELEMENT height (#PCDATA)>
<!ELEMENT name (#PCDATA)>
  8. For each river which crosses at least 2 countries, return its name, and the names of the countries it crosses. Order by the numbers of countries crossed. Place your results into an html file, and verify whether you can/can't view them in your web browser. Turn in the html file along with your query. 
    <!ELEMENT html (head, body)>

<!ELEMENT head (title)>
<!ELEMENT title (#PCDATA)>
<!ELEMENT body (h1, ul)>
<!ELEMENT h1 (#PCDATA)>
<!ELEMENT ul (li+)>
<!ELEMENT li (#PCDATA | font | ol)*>
<!ELEMENT ol (li+)>
<!ELEMENT font (#PCDATA)>
    The idea with the <li> containing a font and ol tag is such that the output looks roughly like: 
    ...
<ul>
  <li>
    <font>River name</font>

    <ol>
      <li>Country crossed #1</li>
      <li>Country crossed #2</li>
      ...
    </ol>

  </li>
  ...
</ul>
    Note: Use the country attribute for the tag <river> to find the respective countries.

    For this problem you need to turn in two files: Problem8.xq and Problem8.html (the output of your query).

  9. Find the countries adjacent to the 'Pacific Ocean' (sea). For this question you are required to validate your output using the w3 markup validator. We will do this for your answer. Follow the instructions above for validating XML in the W3 Markup Validator to validate your results for this problem. whitespace matters when validating the XML, so do not format your query to include whitespace while validating. 
    <!ELEMENT result (waterbody)>
<!ELEMENT waterbody (name, adjacent_countries+)>
<!ELEMENT adjacent_countries (country+)>
<!ELEMENT country (name)>
<!ELEMENT name (#PCDATA)>
    Note: Use the country attribute for the tag <sea> to find the respective countries.