Database System Concepts
Database System Concepts
7th Edition
ISBN: 9780078022159
Author: Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher: McGraw-Hill Education
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Chapter 2, Problem 14E

a.

Explanation of Solution

Query:

ID, person_namecompany_name=”BigBank”(works))

Explanation:

  • The given query is used to find ID and name of each employee who works for BigBank in the employee database...

b.

Explanation of Solution

Query:

πID, person_name, city ( employee ⋈employee.id =works.id ( σcompany_name = "BigBank" ( works )) )

Explanation:

  • The given query is used to find ID, name and city of residence of each employee who works for BigBank in the employee database...

c.

Explanation of Solution

Query:

πID, person_name, street, city ( σ(company_name = "BigBank"   salary > 10000 ( works ⋈employee.id = works.id employee ))

Explanation:

  • The given query is used to find ID, name, street address and city of residence of each employee who works for BigBank and earns more than $10000 in the employee database...

d.

Explanation of Solution

Query:

ID, person_name

employee.city=company.city(employee ⋈employee.id=woks.id works

works.company_name=company.company_name company))

Explanation:

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