Database Concepts (7th Edition)
7th Edition
ISBN: 9780133544626
Author: David M. Kroenke, David J. Auer
Publisher: PEARSON
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Expert Solution & Answer
Chapter 2, Problem 2.26RQ
Explanation of Solution
Meaning of the Equation:
The given expression is,
(D, E)->F
Explanation:
The meaning of the following equation is:
- Given the value for both D and E simultaneously, represented as composite (D, E), user can determine the value of F.
- If one of the values of D or E is not given, user cannot determine the value of F.
- The Composite (D, E) is the determinant of F.
- F is functionally dependent on the composite (D, E).
- It is a composite key.
Example:
- For a table Employee containing attributes ‘employee_id’, ‘employee_name’ and ‘employee_department’, it is observed that user can fill an online form asking to enter the ‘employee_name’ and ‘employee_department’ simultaneously and the
Database Management System (DBMS) searches the employee database and retrieves the information about employee id .
Therefore, expression can be (employee_name, employee_department) -> (employee-id)...
Expert Solution & Answer
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Check out a sample textbook solution
Students have asked these similar questions
Explain the meaning of the following expression: A → (B, C) Given this expression, tell if it is also true that: A → B and: A → C
Consider two operators A and B. What does [A, B] equal? (A) AB−BA
(B) BA−AB(C) AB+BA(D) BA+AB(E) None of the above.
Quadratic Root Solver
For a general quadratic equation y = ax? + bx + c, the roots can be classified into
three categories depending upon the value of the discriminant which is given by
b2 - 4ac
First, if the discriminant is equal to 0, there is only one real root. Then, if the discriminant
is a positive value, there are two roots which are real and unequal. The roots can be
computed as follows:
-b+ Vb? – 4ac
2a
Further, if the discriminant is a negative value, then there are two imaginary roots. In
this case, the roots are given by
b
ь? - 4ас
2a
2a
Programming tasks:
A text file, coeff.txt has the following information:
coeff.txt
3
4
4
4
1
4
Each line represents the values of a, b and c, for a quadratic equation. Write a program
that read these coefficient values, calculate the roots of each quadratic equation, and display
the results. Your program should perform the following tasks:
• Check if the file is successfully opened before reading
• Use loop to read the file from main…
Chapter 2 Solutions
Database Concepts (7th Edition)
Ch. 2 - Prob. 2.1RQCh. 2 - Define the term entity, and give an example of an...Ch. 2 - Prob. 2.3RQCh. 2 - Prob. 2.4RQCh. 2 - Prob. 2.5RQCh. 2 - Prob. 2.6RQCh. 2 - Prob. 2.7RQCh. 2 - Prob. 2.8RQCh. 2 - Prob. 2.9RQCh. 2 - Define the term unique key and give an example.
Ch. 2 - Prob. 2.11RQCh. 2 - Prob. 2.12RQCh. 2 - Prob. 2.13RQCh. 2 - Describe four uses of a primary key.Ch. 2 - Prob. 2.15RQCh. 2 - Prob. 2.16RQCh. 2 - Prob. 2.17RQCh. 2 - Explain the term foreign key, and give an example.Ch. 2 - Prob. 2.19RQCh. 2 - Prob. 2.20RQCh. 2 - Explain three possible interpretations of a null...Ch. 2 - Give an example of a null value (other than one...Ch. 2 - Prob. 2.23RQCh. 2 - Prob. 2.24RQCh. 2 - Prob. 2.25RQCh. 2 - Prob. 2.26RQCh. 2 - Prob. 2.27RQCh. 2 - Define the term primary key in terms of functional...Ch. 2 - Prob. 2.31RQCh. 2 - Examine the data in the Veterinary Office...Ch. 2 - Prob. 2.33RQCh. 2 - Describe a modification problem that occurs when...Ch. 2 - Prob. 2.35RQCh. 2 - Prob. 2.36RQCh. 2 - Prob. 2.37RQCh. 2 - Apply the normalization process to the Veterinary...Ch. 2 - Prob. 2.39ECh. 2 - Prob. 2.40E
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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.Similar questions
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- Objective: The objective of this discussion is to be aware of the field of logic. Problem Statement: Consider the statement: "There is a person x who is a student in CSEN 5303 and has visited Mexico" Explain why the answer cannot be 3r (S(x)→ M(x)).arrow_forwardLet I(x) be the statement "x has an Internet connection" and C(x, y) be the statement "x and y have chatted over the Internet," where the domain for the variables x and y consists of all students in your class. Use quantifiers to express each of these statements. i) Everyone in your class with an Internet connection has chatted over the Internet with at least one other student in your class. ii) Someone in your class has an Internet connection but has not chatted with anyone else in your class. Express each of these system specification using predicates, quantifiers and logical operators if necessary. i) There are at least two paths connecting every two distinct end points of the network. ii) No one knows the password of every user except for the system administrator who knows all password.arrow_forward[The [CO#] represents mapping of the question with one of the expected outcomes of the course.]arrow_forward
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