DATABASE SYSTEM CONCEPTS (LOOSELEAF)
7th Edition
ISBN: 9781260515046
Author: SILBERSCHATZ
Publisher: MCG
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Chapter 3, Problem 30E
Explanation of Solution
Explanation:
- For numeric values it will always be zero. But when there is a null value the answer will be undefined.
- When there is any instant with value equal to null then the answer will be undefined which is not equal to zero...
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(d) Write an SQL statement, using the inner join construct, that will, for the lecturer John Smith, list in alphabetical order the students taking any module which he teaches.
(e) What information does the output from the following SQL query provide?
SELECT Lecturer, COUNT(DISTINCT Student)
FROM class INNER JOIN staff
ON class.Module = staff.Module
WHERE Grade < 40
GROUP BY Lecturer;
(f) Write an SQL query which would obtain the following information: for each lecturer, what is the average grade obtained by students across all of the modules which they have taught?
2) Write SQL query that returns the Name of ALL employees (based on EMP_LNAME and EMP_FNAME in EMPLOYEE table, call this EMP_NAME), Gender of ALL employees (based on EMP_TITLE in EMPLOYEE table, call this EMP_NAME), and Pilot ratings if any (PIL_RATINGS in PILOT table).
Output:
EMP_NAME
EMP_GENDER
Rhett VanDam
M
John Lange
M
Jeanine Duzak
F
Chapter 3 Solutions
DATABASE SYSTEM CONCEPTS (LOOSELEAF)
Ch. 3 - Prob. 1PECh. 3 - Prob. 2PECh. 3 - Prob. 3PECh. 3 -
Suppose that we have a relation marks(ID, score)...Ch. 3 - Suppose that we have a relation marks(ID, score)...Ch. 3 -
The SQL like operator is case sensitive (in most...Ch. 3 - Prob. 7PECh. 3 - Prob. 8PECh. 3 - Prob. 9PECh. 3 - Prob. 10PE
Ch. 3 - Prob. 11ECh. 3 - Prob. 12ECh. 3 - Prob. 13ECh. 3 -
Consider the insurance database of Figure 3.17,...Ch. 3 - Prob. 15ECh. 3 - Prob. 16ECh. 3 - Prob. 17ECh. 3 - Prob. 18ECh. 3 -
List two reasons why null values might be...Ch. 3 - Prob. 20ECh. 3 - Prob. 21ECh. 3 - Prob. 22ECh. 3 - Prob. 23ECh. 3 - Prob. 24ECh. 3 - Prob. 25ECh. 3 - Prob. 26ECh. 3 - Using the university schema, write an SQL query to...Ch. 3 - Prob. 28ECh. 3 - Prob. 29ECh. 3 - Prob. 30ECh. 3 - Prob. 31ECh. 3 - Prob. 32ECh. 3 - Prob. 33ECh. 3 - Prob. 34ECh. 3 - Prob. 35E
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