databases multi-part question and need the explanation and answer to help me learn.
Q1: In a train stations database, an employee MUST be a train driver, ticket issuer or train attendant, with following constraint: Same employee cannot occupy more than one job type.
Draw EER diagram to represent specialization of employees in the train station database.
Q2: Draw the schema mapping (logical database design) for the following part of ER diagram for train station database. When appropriate use the foreign key option.
Q3: Suppose you are creating a database for a library management system. Explain how you would create a table for the “books” entity and insert some sample data, and then alter the table to add a new column for the “authorID” attribute and update “authorID” with some data. Finally, write a SQL query to retrieve all the books that were published after the year 2000.
Note that this book schema has several columns, including “book_id” as the primary key, “title”, “authorN”, “publisher”, “publication_year”, “isbn”, “language”, and “num_pages”. It also includes “available” column that is set to “true” by default and can be used to track the availability of the book.
Q4: Write a SQL query that retrieves the names and email addresses of all students who are enrolled in at least one course in the “Computer Science” department and have a graduation year of 2022 or later. Include the course name and instructor name for each enrollment in the output. Schemas of the tables are below.
“students” table:
student_id: unique identifier for the student
name: name of the student
email: email address of the student
major: field of study for the student
graduation_year: expected year of graduation for the student
“courses” table:
course_id: unique identifier for the course
course_name: name of the course
instructor_name: name of the instructor teaching the course.
department: department offering the course.
course_description: description of the course
“enrollments” table:
enrollment_id: unique identifier for the enrollment
student_id: identifier for the student enrolled in the course.
course_id: identifier for the course the student is enrolled in
enrollment_date: date the student enrolled in the course
grade: grade the student received in the course
Requirements: Explanation and answer
We are a professional custom writing website. If you have searched a question and bumped into our website just know you are in the right place to get help in your coursework.
Yes. We have posted over our previous orders to display our experience. Since we have done this question before, we can also do it for you. To make sure we do it perfectly, please fill our Order Form. Filling the order form correctly will assist our team in referencing, specifications and future communication.
1. Click on the “Place order tab at the top menu or “Order Now” icon at the bottom and a new page will appear with an order form to be filled.
2. Fill in your paper’s requirements in the "PAPER INFORMATION" section and click “PRICE CALCULATION” at the bottom to calculate your order price.
3. Fill in your paper’s academic level, deadline and the required number of pages from the drop-down menus.
4. Click “FINAL STEP” to enter your registration details and get an account with us for record keeping and then, click on “PROCEED TO CHECKOUT” at the bottom of the page.
5. From there, the payment sections will show, follow the guided payment process and your order will be available for our writing team to work on it.
Need this assignment or any other paper?
Click here and claim 25% off
Discount code SAVE25