Why should you care?

Every Flipkart search, Swiggy order total, and bank balance check runs SQL (or something that compiles to it) behind the scenes. Learning SQL lets you read and fix the data layer directly.

See it live — copy this example

Run in MySQL Workbench or the mysql CLI.

-- DataFlow: list table names in the current schema
USE DataFlow;
SHOW TABLES;

What happened?

• USE DataFlow switches your session to the DataFlow database.
• SHOW TABLES lists every table you can query there.
• This is your first look at what data the app actually stores.

Practice next

1. Open MySQL Workbench and connect to your local server.
2. Run USE DataFlow; (create the database first if needed: CREATE DATABASE DataFlow;).
3. Run SHOW TABLES; and note the names.
4. Run SHOW DATABASES; and count how many exist.
5. Create DataFlow with CREATE DATABASE IF NOT EXISTS DataFlow; then USE it again.

Remember

SQL reads and writes relational data. SHOW and USE are basic navigation commands. DataFlow is the practice database for this course.

DataFlow onboarding query

A new backend engineer joins and runs SHOW TABLES on DataFlow to map customers, orders, and products before writing APIs.

Outcome: They know which tables exist before touching production-like data.