README.md

Lab | SQL Select

Introduction

In this lab you will practice how to use the SQL SELECT statement. You will use the publications database.

Open the publications.sqlite database in DB Browser for SQLite by selecting Open Database and choosing the publications.sqlite file. Once it's open, you can start working on your lab in the Execute SQL section. Don't forget to save your code regularly.

You will create a solutions.sql file in the your-code directory to record your solutions to all challenges.

You can explore your database and table on your own, but here's a quicker view of how the DB is modeled:

Challenge 1 - Who Have Published What At Where?

In this challenge you will write an SQL SELECT query that joins various tables to figure out what titles each author has published at which publishers. Your output should have at least the following columns:

• AUTHOR ID - the ID of the author
• LAST NAME - author last name
• FIRST NAME - author first name
• TITLE - name of the published title
• PUBLISHER - name of the publisher where the title was published

Your output will look something like below:

Note: the screenshot above is not the complete output.

If your query is correct, the total rows in your output should be the same as the total number of records in Table titleauthor.

Challenge 2 - Who Have Published How Many At Where?

Elevating from your solution in Challenge 1, query how many titles each author has published at each publisher. Your output should look something like below:

Note: the screenshot above is not the complete output.

To check if your output is correct, sum up the TITLE COUNT column. The sum number should be the same as the total number of records in Table titleauthor.

Hint: In order to count the number of titles published by an author, you need to use the SQL COUNT function. Also, check out GROUP BY because you will count the rows of different groups of data. Refer to the references and learn by yourself. These features will be formally discussed in the Temp Tables and Subqueries lesson.

Challenge 3 - Best Selling Authors

Who are the top 3 authors who have sold the highest number of titles? Write a query to find out.

Requirements:

• Your output should have the following columns:
  • AUTHOR ID - the ID of the author
  • LAST NAME - author last name
  • FIRST NAME - author first name
  • TOTAL - total number of titles sold from this author
• Your output should be ordered based on TOTAL from high to low.
• Only output the top 3 best selling authors.

Challenge 4 - Best Selling Authors Ranking

Now modify your solution in Challenge 3 so that the output will display all 23 authors instead of the top 3. Note that the authors who have sold 0 titles should also appear in your output (ideally display 0 instead of NULL as the TOTAL). Also order your results based on TOTAL from high to low.

Deliverables

• solution.sql that contains all your MySQL queries.

Submission

• Add solutions.sql to git.
• Commit your code.
• Push to your fork.
• Create a pull request to the class repo.

References

• SQLite Reference: COUNT Function
• SQLite Reference: SUM Function