Question: Consider the following relational data:
pid Name Price Description
323 gizmo 22.99 great
233 gizmo plus 99.99 more features
312 gadget 59.99 good value
Table 1: Products
sid Name Phone
s282 Wiz 555-1234
s521 Econo-Wiz 555-6543
Table 2: Stores
pid Markup sid
323 10% s521
233 25% s282
233 15% s521
Table 3: Sells
1. We want to export this data into an XML file. Write a DTD describing the following structure for the XML file:
• there is one root element called products
• the products element contains a sequence of product sub elements, one for each product in the database
• each product element contains one name, one price, and one description subelement, and a sequence of store
subelements, one for each store that sells that product:
• each store element contains one name, one phone, and one markup .
Write the XML document obtained by exporting the database above; you have to turn in an XML document called Products.xml. Place the DTD on the top of Products.xml. Validate the xml file with xmllint.
2. Assuming that you have XML documents with the structure given in 1, write an XQuery that returns the names and prices of all products that are sold at least at one store with a markup of 25%. Write the same query in SQL over the original relational database schema. Turn in the two queries.
3. Assume the same database is represented in an XML document whose structure follows the relational tables:
323
gizmo
22.99
great
...
...
|
|
|
|
... ...
...
...
Write an XQuery that, when given an input with the structure described in 1), constructs an XML document with this structure. You have to turn in a XQuery.