Northwind.sql

SQL Database for Practice & Learning

This repository contains the W3Schools SQL database, cleaned and formatted for use in DB Fiddle (MySQL 8.0). It includes 8 tables: Categories, Customers, Employees, Orders, OrderDetails, Products, Shippers, and Suppliers. The data is ideal for practicing SQL queries.

Table Structure

• Categories: 8 records (product categories)
• Customers: 91 records (customer details)
• Employees: 10 records (employee details)
• Orders: 401 records (customer orders)
• OrderDetails: 518 records (order items)
• Products: 77 records (product details)
• Shippers: 3 records (shipping companies)
• Suppliers: 29 records (product suppliers)

How to Use

1. Go to DB Fiddle.
2. Select MySQL 8.0 as the database engine.
3. Copy the SQL code from one of the .sql files (e.g., customers.sql) or use w3schools_full.sql for the entire database.
4. Paste the code into the Schema panel (left side).
5. Click Run to create the tables and insert data.
6. Write and test your SQL queries in the Query panel (right side).
7. Save or share your fiddle using the provided URL.

Note: Insert tables in dependency order (Categories, Suppliers, Products, Customers, Employees, Shippers, Orders, OrderDetails) to avoid foreign key errors.

Files

• Categories.sql: Schema and data for Categories table.
• Customers.sql: Schema and data for Customers table.
• Employees.sql: Schema and data for Employees table.
• Orders.sql: Schema and data for Orders table.
• OrderDetails.sql: Schema and data for OrderDetails table.
• Products.sql: Schema and data for Products table.
• Shippers.sql: Schema and data for Shippers table.
• Suppliers.sql: Schema and data for Suppliers table.
• ConcatentedData.sql: Combined schema and data for all tables.

Cleaning Applied

• Set NULL PostalCode in Customers to 'Unknown'.
• Removed spaces from PostalCode in Customers and Suppliers.
• Normalized Phone formats in Suppliers and Shippers (e.g., '(503) 555-9831' → '503-555-9831').
• Rounded Price in Products to 2 decimal places.

Tips

• If DB Fiddle is slow, use individual table files or a subset of the data.
• For local testing, import the .sql files into MySQL Workbench or a similar tool.
• Practice queries like SELECT, JOIN, GROUP BY, and SUBQUERY using this dataset.

License

This dataset is provided for educational purposes. Feel free to use and share it for teaching SQL.