The cardinality ratio depends on the real-world meaning of the entity types involved and is defined by the specific application. For the binary relationships below, suggest the cardinality ratios based on your understanding. Clearly state any assumptions you make. Entity 1 Cardinality Ratio Entity 2 1 Student Social Security No. 2 Student Teacher 3 Classroom Wall 4 Course Text Book %23

The cardinality ratio depends on the real-world meaning of the entity types involved and is defined by the specific application. For the binary relationships below, suggest the cardinality ratios based on your understanding. Clearly state any assumptions you make. Entity 1 Cardinality Ratio Entity 2 1 Student Social Security No. 2 Student Teacher 3 Classroom Wall 4 Course Text Book %23

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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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
Suppose that we wish to keep a genealogy. The information we wish to record about each person includes their name, date of birth, phone number, and degrees obtained . We also need to keep track of the mother, father, and children of each person. Draw a complete Entity-Relationship diagram. You must include all the details, sad as keys, weak entities (if any), cardinality constraints, etc. Your diagram must avoid redundancy.
Which of the following criteria would make an entity a weak entity? a.) If the primary key is not derived from the parent entity in the relationship b.) If the entity can exist without the entity with which it has a relationship c.) If the primary key of a related entity contains the primary key of the parent entity d.) If the entity has a primary key that is partially derived from the parent entity
Applying your knowledge in Enhanced Entity Relationship modeling, Develop an EER model for the following situation: A person may be employed by one or more organizations and each organization may be the employer of one or more persons. An organization can be internal organizational unit or an external organization. For persons and organizations, we want to know their ID, name, address and phone number. For persons we want to know their birthdate, and for organizations, we want to know their budget number. For each 6 employment, we want to know the employment date, termination date and bonus. Employment of a person by an organization may result in the person holding many positions over time. For each position, we know its title, and each time someone holds that position, we need to know the start date and termination date and salary. An organization is responsible for each position. It is possible for a person to be employed by one organization and hold a position for which another…
Question 20 Which of the following might result from a many-to-many relationship? Group of answer choices exclusive subtype intersection data supertype entity recursive relationship
Computer Science Design an Extended Entity Relationship Model with appropriate cardinality and appropriate entity names which can later be used in SQL to test queries and validate entity relations for the following case. The car hire company caters for both corporate and individual customer hire. Corporate customers are allocated a type, gold, silver or bronze based on the frequency of hire arranged in the contract. Vehicles on corporate and/or individual hire can be collected at any centre and dropped at any centre (with no surcharge for a different centre). Hire charges are based on vehicle classifications (e.g. Luxury Saloon, Basic Hatchback ....) Each classification will include a variety of models (e.g. Ford Fiesta 1.1, Fiat Panda ....are in the ‘Basic Hatchback’ classification). Charges for classifications are by the day. A customer collecting a car at a particular centre will be charged according to the charges for that centre.
What is the attribute that could be obtained using other attributes in the Entity-Relationship Diagram? Select one: a.Multi-Valued Attribute b.Derived / Calculates Attribute c.Single-Valued Attribute d.Composite Attribute
Given an EMPLOYEE entity with the following attributes: EMP_NUMBER, EMP_ADDRESS, EMP_QUALIFICATION, EMP_BIRTHDATE and EMP_AGE Based on the list of attributes above, give one example: Composite attribute Derived Attribute i. ii. Single-value attribute Multivalued attribute ii. iv. V. Primary key
For each of the following collection of entities, give the assumptions concerning the relationship between entities and attributes. EMPLOYEE(EMP_NUM, EMP_LNAME, EMP_INITIAL, EMP-DOB) DEPENDENT(EMP_NUM, DEP_NUM, DEP_FNAME, DEP_DOB)
Prepare a Crow’s Foot Entity Relationship Diagram for the application described in the following paragraph. Many-to-Many relationships should be broken into two 1-to-Many relationships using a bridge entity. Label PK attributes and FK when applicable. For each entity, you need to define a primary key. If there is a relationship between two entities make sure you define the corresponding foreign key in the child table. Seneca Sandlot Baseball is a recreational baseball league for Seneca students. The league has different divisions for different skill levels. Each player’s skills are evaluated and the player is assigned to a division. A team is made up of many players from the same division, and a coach. A player may play on only one team in the league. Each division is made up of many teams. A coach may coach teams in more than one division , but can only coach one team in each division. A coach may not play on any team in the league. A season is twelve weeks in length.…
When an attribute should be extracted from one entity type and placed in a related entity type, state the rule.
You are given an E-R diagram with two entities Orders and Customers. What does the lone between the Customers entity and the Place relationship represent?