CASE Statements: The IF-THEN of SQL

It's **Day 77**, and we're learning how to build our own logic into queries using the `CASE` statement.

What is a CASE Statement?

It's the SQL version of an "If-Else" block. It allows you to create new values based on existing data.

Real-World Example: Fixing Country Names

SELECT

name,

CASE

WHEN country = 'USA' THEN 'United States'

WHEN country = 'US' THEN 'United States'

WHEN country = 'U.K.' THEN 'United Kingdom'

ELSE country -- Keep the original if it doesn't match

END AS clean_country

FROM users;

Creating Categories

PMs often ask for data to be "Bucketed."

SELECT

product_name,

price,

CASE

WHEN price < 50 THEN 'Budget'

WHEN price BETWEEN 50 AND 200 THEN 'Mid-Range'

ELSE 'Premium'

END AS price_tier

FROM products;

Why it's critical

`CASE` statements allow you to normalize data *at the query level* without waiting for a database migration. It's the fastest way to fix a report that's broken by messy input.

Your Task for Today

Create a `CASE` statement that turns a numerical `status_code` (1, 2, 3) into readable text (Active, Pending, Deleted).

*Day 78: Handling Hidden Spaces—TRIM, LTRIM, RTRIM.*