E-R model:
- It is a tool for creating data model.
- It is used for developers to describe the content of data model by using two functions called entities and relationships.
Entity:
- It helps the user for tracking something in
database . - Example entities in student database system are Student, Grade, Course, etc.
Relationships:
- Entities have relationships among each other.
- For example, in student database, a Student has a relationship to Major and Student has a relationship to Advisor.
Attribute:
- It used to describe the entity characteristics.
- Example attributes of student entity is Student_id, Student_name, Student_address, etc.
Identifier:
- It is an attribute or group of attribute, but its value is related with one and only one entity instance.
Example of E-R diagram:
Explanation of Solution
Entity Relationship diagram that displays relationship among the database, database application and users:
The below is the E-R diagram that shows the relationship that is laid among the database, database application and users:
User:
The person or end user that can process the application that is stored in the database.
Database application:
A database application is a collection of four elements namely forms, reports, queries and application which acts as an intermediate between the user and data of the database
Database:
Database is a collection of information that is used to store and retrieve the data. Data is organized in tables.
Explanation of the E-R diagram:
- Many user can use the database application.
- Example of the user entity could be “students”, “faculty”.
- Many database applications can be present in a single database.
- Example of the database application could be “Bookstore”,”Library”.
- Only one database can contain many database application.
- Example of the database could be “studentDB”,”BookStoreDB”.
- The relationship between the user and the database application is “M:N (Many to many )relationship.
- The relationship between the database application and theDatbase is “N:1”(Many to One) relationship.
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Chapter 5 Solutions
Using MIS (9th Edition)
- EX:[AE00]=fa50h number of ones =1111 1010 0101 0000 Physical address=4AE00h=4000h*10h+AE00h Mov ax,4000 Mov ds,ax; DS=4000h mov ds,4000 X Mov ax,[AE00] ; ax=[ae00]=FA50h Mov cx,10; 16 bit in decimal Mov bl,0 *: Ror ax,1 Jnc ** Inc bl **:Dec cx Jnz * ;LSB⇒CF Cf=1 ; it jump when CF=0, will not jump when CF=1 HW1: rewrite the above example use another wayarrow_forwardEX2: Write a piece of assembly code that can count the number of ones in word stored at 4AE00harrow_forwardWrite a program that simulates a Magic 8 Ball, which is a fortune-telling toy that displays a random response to a yes or no question. In the student sample programs for this book, you will find a text file named 8_ball_responses.txt. The file contains 12 responses, such as “I don’t think so”, “Yes, of course!”, “I’m not sure”, and so forth. The program should read the responses from the file into a list. It should prompt the user to ask a question, then display one of the responses, randomly selected from the list. The program should repeat until the user is ready to quit. Contents of 8_ball_responses.txt: Yes, of course! Without a doubt, yes. You can count on it. For sure! Ask me later. I'm not sure. I can't tell you right now. I'll tell you after my nap. No way! I don't think so. Without a doubt, no. The answer is clearly NO. (You can access the Computer Science Portal at www.pearsonhighered.com/gaddis.)arrow_forward
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