subject

For each of the descriptions below, perform the following tasks: i. Identify the degree and cardinalities of the relationship.
ii. Express the relationships in each description graphically with an E-R diagram.

a. A book is identified by its ISBN number, and it has a title, a price, and a date of publication. It is published by a publisher, which has its own ID number and a name. Each book has exactly one publisher, but one publisher typically publishes multiple books over time.
b. A book is written by one or multiple authors. Each author is identified by an author number and has a name and date of birth. Each author has either one or multiple books; in addition, occasionally data are needed regarding prospective authors who have not yet published any books.
c. In the context specified in 2a and 2b, better information is needed regarding the relationship between a book and its authors. Specifically, it is important to record the percentage of the royalties that belongs to a specific author, whether or not a specific author is a lead author of the book, and each author's position in the sequence of the book's authors.
d. A book can be part of a series, which is also identified as a book and has its own ISBN number. One book can belong to several sets, and a set consists of at least one but potentially many books.
e. A piano manufacturer wants to keep track of all the pianos it makes individually. Each piano has an identifying serial number and a manufacturing completion date. Each instrument represents exactly one piano model, all of which have an identification number and a name. In addition, the company wants to maintain information about the designer of the model. Overtime, the company often manufactures thousands of pianos of a certain model, and the model design is specified before any single piano exists.
f. A piano manufacturer (see 2e) employs piano technicians who are responsible for inspecting the instruments before they are shipped to the customers. Each piano is inspected by at least two technicians (identified by their employee number). For each separate inspection, the company needs to record its date and a quality evaluation grade.
g. The piano technicians (see 2f) have a hierarchy of reporting relationships: Some of them have supervisory
responsibilities in addition to their inspection role and have multiple other technicians report to them. The supervisors themselves report to the chief technician of the company.
h. A vendor builds multiple types of tablet computers. Each has a type identification number and a name. The key
specifications for each type include amount of storage space and display type. The company uses multiple processor types, exactly one of which is used for a specific tablet computer type; obviously, the same processor can be used in multiple types of tablets. Each processor has a manufacturer and a manufacturer's unique code that identifies it.
i. Each individual tablet computer manufactured by the vendor (see 2h) is identified by the type identification number and a serial number that is unique within the type identification. The vendor wants to maintain information about when each tablet is shipped to a customer.
j. Each of the tablet computer types (see 2h) has a specific operating system. Each technician the company employs is certified to assemble a specific tablet type—operating system combination. The validity of a certification starts on the day the employee passes a certification examination for the combination, and the certification is valid for a specific period of time that varies depending on tablet type—operating system combination.

ansver
Answers: 1

Another question on Computers and Technology

question
Computers and Technology, 23.06.2019 00:40
Consider the following statements: struct nametype{string first; string last; }; struct coursetype{string name; int callnum; int credits; char grade; }; struct studenttype{nametype name; double gpa; coursetype course; }; studenttype student; studenttype classlist[100]; coursetype course; nametype name; mark the following statements as valid or invalid. if a statement is invalid, explain why.a.) student.course.callnum = "csc230"; b.) cin > > student.name; c.) classlist[0] = name; d.) classlist[1].gpa = 3.45; e.) name = classlist[15].name; f.) student.name = name; g.) cout < < classlist[10] < < endl; h.) for (int j = 0; j < 100; j++)classlist[j].name = name; i.) classlist.course.credits = 3; j.) course = studenttype.course;
Answers: 1
question
Computers and Technology, 24.06.2019 22:00
Ican’t open these when it’s just a comment. someone pls explain why this is happening
Answers: 1
question
Computers and Technology, 25.06.2019 06:00
Write a method public static string getdigits(string phonenumber) that takes an 11-character phone number written with any combination of 11 uppercase letters, lowercase letters and/or digits, and zero or more hyphens, and which returns the digits that a person would have to press on a cell phone to dial that phone number. we will use the mapping of letters to digits given at en.wikipedia.org/wiki/telephone_keypad# /media/file: telephone-keypad2.svg you may assume that the string parameter phonenumber contains some combination of exactly 11 uppercase letters, lowercase letters and/or digits, but that any number of hyphens may be present. you can assume that a hyphen will not appear as the first or last character of the string. do not assum
Answers: 3
question
Computers and Technology, 25.06.2019 08:30
When converting the erd to a table design, how should you handle the assignedto relationship? (be sure to include a discussion of primary keys, foreign keys, and tables in your answer.)11. true/false projectid will be a foreign key in the employees table to reflect the “manages” relationship.12. after converting the erd to a table design, what fields will be present in the contracts
Answers: 3
You know the right answer?
For each of the descriptions below, perform the following tasks: i. Identify the degree and cardina...
Questions
question
English, 21.10.2019 22:20
question
History, 21.10.2019 22:20
Questions on the website: 13722367