Consider the ER diagram in work in up to two departments or may not be assigned to any department. Assume that each department must have one and may have up to three phone numbers. Supply (min, max) constraints on this diagram. State clearly any additional assumptions you make. Under what conditions would the relationship HAS_PHONE be redundant in this example? Assume that an employee may

Consider the ER diagram in work in up to two departments or may not be assigned to any department. Assume that each department must have one and may have up to three phone numbers. Supply (min, max) constraints on this diagram. State clearly any additional assumptions you make. Under what conditions would the relationship HAS_PHONE be redundant in this example? Assume that an employee may

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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Determine the highest normal form (1NF, 2NF, 3NF, or BCNF) for each one of the following six relations. Notice that the primary key of each relation is underlined.) 1 2 3 4 5 6 Relations Work (EmpNumber, ProjectNumber) Work (EmpNumber, ProjectNumber, ManagerSSN) Given that a project has one manager only. Work (EmpNumber, ProjectNumber, HoursPerWeek) Work (EmpNumber, ProjectNumber, EmpName, Location) Given that a project is located in one location only. Work (EmpNumber, ProjectNumber, Location) Given that a project is located in one location only. Work (EmpNumber, ProjectNumber, Location) Given that a location has one project only. Answers
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Create an Entity Relationship diagram (ERD) for the following scenario indicating the identifiers and cardinality constraints. A division operates many departments, but each department is operated by only one division. Each division must have at least one department and each department must belong to a division. A department employs many employees, but there may be a department with no employees. Division is characterised by Divisionid and Divisionname and the attributes of department include Deptid and Deptname. Majority of employees called “dept_emps” are employed by a department. However, there are also employees known as “free_lance_emps” who are not assigned to any department. A department may own many projects, but there may be a department with no projects. Employee is characterised by empid, empname, emptype and address. Both dept_emps and free_lance_emps can work on many projects, but there are employees who do not work on any project. A project has at least one employee…
The Acme Company wants to construct a database to keep track of the company’s employees, departments, and projects as well as the employee’s dependents. Draw the entity-relationship model. The requirements collected to date to be modeled are: The company is organized into departments. Each department has a name, a number, and an employee who manages the department. A department controls a number of projects, each of which has a name, a number, and a start date but not all departments have projects assigned to them. We store each employee’s name, social security number, address, salary, sex, and birth date. Every employee is assigned to a department but may work on several projects, which are not necessarily under the control of the same department. We keep track of the number of hours per week that each employee works on each project. For most projects, a team of employees is assigned to work on the project while some employees are never assigned to a project. We also keep track…
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(1) Draw an ER Diagram for the scenario below Temporary Employment Corporation (TEC) places temporary workers in companies during peak periods. TEC's manager gives you the following description of the business: TEC has a file of candidates who are willing to work. • If the candidate has worked before that candidate has a specific job history. • Each candidate has several qualifications. TEC also has a list of companies that request temporaries. Each time a company requests a temporary employee, TEC makes an entry in the openings folder. The folder contains an opening number, company name, required qualifications, starting date, anticipated ending date, and hourly pay. • • Each opening requires only one specific or main qualification. When a candidate matches the qualification, he/she is given the job, and an entry is made in the Placement Record folder. This folder contains an opening number, candidate number, total hours worked, and so on. In addition, an entry is made in the job…
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Explain the relationship in the below Entity Relationship Diagram (ERD) inyour own words.Answer the following questions by referring to the below sample data.
A company keeps track of its departments, employees and mobile numbers assigned to employees by the department. Draw an ER diagram using the (min,max) notation for structural constraints, given that: An employee has a unique id, name and can have more than one address A department has a unique id, name and one address A mobile is identified by its number An employee must work in one department only A department has a minimum of 4 employees A department can own up to 10 mobiles An employee can be assigned up to 2 mobiles State any assumptions you make.
15. Below is a fragment of the entity-relationship diagram. For the relationship shown, identify its relationship, cardinality, and existence. Employee is assigned to Parking Space a. Relationship: one-to-many Cardinality: zero or one employee per parking space, one or many parking spaces per employee Existence: parking space required, employee optional Ob. Relationship: zero-to-one Cardinality: zero or one employee per parking space, one or many parking spaces per employee Existence: parking space required, employee required О с. Relationship: zero-to-one Cardinality: zero or one employee per parking space, one or many parking spaces per employee Existence: parking space required, employee optional Od. Relationship: one-to-one Cardinality: zero or one employee per parking space, one or many parking spaces per employee Existence: parking space required, employee optional
It is requested to draw an entity relationship diagram (ERD) for a hospital management system. Information about the subject are given below. • The patients contain ID, name, and surname. Doctors have name, surname, and department. Rooms have number and capacity. • Each doctor may supervise zero or more patients. • Each patient should be supervised by one doctor. • Each room may host zero or more patients. Each patient should be hosted in one room.
In LAU the ERD diagram representing the Professor entity " teaching " student entity is many to many. Attributes for the " professor entity " are : Prof.ID , Prof.Name , Prof.Address and Prof.DOB, Course time and course location. The attributes for the student entity are: Student ID , Student Name , Student Address , Student Major , Exam1_Grade , Exam2_Grade , course schedule , course location and total_grade. Business Rule 1: Many Professor may teach none , one or Many students a) Draw the ERD Diagram as described above. b) After starting the three rules of normalization , what are consideration you may want to follow to maintain a proper design of the database ? Show the new design by re-drawing the proper design according to the normalization rules. This question are related to ITM211 course!