Building a Sample Database

In this tutorial, you'll embark on a hands-on project where you'll design and create a sample database. This practical exercise is essential for applying the knowledge you've gained throughout the course and gaining real-world experience in database design and SQL.

Lesson 1: Database Design Principles

Before creating a database, it's crucial to understand the principles of good database design. This involves making decisions about how data is organized, structured, and related within the database. Key concepts to remember:

• Normalization: The process of organizing data to minimize data redundancy and improve data integrity. It involves breaking down data into smaller, related tables.
• Primary Keys: A unique identifier for each record in a table. It ensures that each record can be uniquely identified.
• Foreign Keys: A field in one table that links to the primary key of another table, establishing relationships between tables.

Lesson 2: Creating the Sample Database

For our sample project, let's consider a simple library database to manage books, authors, and patrons. We'll create three tables: Books, Authors, and Patrons.

-- Create the Books table

CREATE TABLE Books (

    BookID INT PRIMARY KEY,

    Title VARCHAR(255),

    AuthorID INT,

    PublicationYear INT

);

-- Create the Authors table

CREATE TABLE Authors (

    AuthorID INT PRIMARY KEY,

    FirstName VARCHAR(50),

    LastName VARCHAR(50)

);

-- Create the Patrons table

CREATE TABLE Patrons (

    PatronID INT PRIMARY KEY,

    FirstName VARCHAR(50),

    LastName VARCHAR(50)

);

In this code:

• We create the "Books," "Authors," and "Patrons" tables.
• Each table has primary keys to ensure data integrity.
• The "AuthorID" in the "Books" table is a foreign key that links to the "Authors" table, establishing a relationship between the two.

Lesson 3: Inserting Sample Data

Now, let's insert some sample data into our newly created tables:

-- Insert data into the Authors table

INSERT INTO Authors (AuthorID, FirstName, LastName)

VALUES (1, 'Jane', 'Austen');

-- Insert data into the Books table

INSERT INTO Books (BookID, Title, AuthorID, PublicationYear)

VALUES (1, 'Pride and Prejudice', 1, 1813);

In this code:

• We insert an author, Jane Austen, into the "Authors" table.
• We insert a book, "Pride and Prejudice," into the "Books" table. The "AuthorID" links to Jane Austen in the "Authors" table.

Hands-On Practice:

• Continue adding more sample data to the "Authors," "Books," and "Patrons" tables. Experiment with different book titles, authors, and patron information.
• Create relationships between the tables by using foreign keys in the "Books" and "Patrons" tables.

Key Takeaways:

• Good database design involves principles like normalization, primary keys, and foreign keys.
• Creating tables with appropriate structure is essential for data integrity.
• Sample data can be inserted into the tables to make the database practical and functional.

Homework Assignment:

For this week's assignment, continue building your sample database. Add more data to the "Authors," "Books," and "Patrons" tables. Pay special attention to creating relationships between the tables using foreign keys. Practice writing SQL statements to retrieve data from your sample database. In the next session, we will explore real-world projects involving database design and SQL queries, so make sure your sample database is ready for use.

You've reached an exciting point in your SQL journey, as you're now able to create practical databases and tables. Stay motivated and keep experimenting!