Classroom Exercise: SQL
 Consider a bookstore database with this schema:
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Books(bookid, title, author, year)
Customers (customerid, name, email)
Purchases (customerid, bookid, year)
Reviews (customerid, bookid, rating) // rating is 1, 2, 3, …
Pricing (bookid, format, price) // format is 'audio', 'hb', 'pb',…
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2.
titles of all books written by 'EDMUND MORGAN' since 1990
titles, authors and prices of all books with 'CIVIL WAR' in the title
available in audio
list how many books 'JOHN SMITH' bought in each year that he
bought at least one book
names and email addresses of all customers who bought more
than one book in 2003
titles, authors, and average ratings for all books with 'CIVIL WAR'
in the title
 Write SQL queries to find the following information:
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5.
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Normalization Example
Consider relation R(name, SSN, BD, childName,
childSSN, childBD, VIN, make)
Assume these FDs:
 SSN -> name BD
 childSSN -> childName childBD
 VIN -> make
Therefore key is {SSN,childSSN,VIN} and all FDs
violate BCNF.
Assume these MVDs:
 SSN ->-> childSSN childName childBD
 SSN ->-> VIN make
Thus all MVDs violate 4NF.
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Normalization Ex. cont'd
Decompose R using
SSN ->-> childSSN childName childBD:
 R1(SSN,childSSN,childName,childBD)
 R2(SSN,name,BD,VIN,make)
Decompose R2 using SSN ->-> VIN make:
 R2.1(SSN,VIN,make)
 R2.2(SSN,name,BD)
Decompose R1 using childSSN -> childName childBD:
 R1.1(childSSN,childName,childBD)
 R1.2(SSN,childSSN)
Decompose R2.1 using VIN -> make:
 R2.1.1(VIN,make)
 R2.2.2(SSN,VIN)
final set of relations
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