Range Finder: The BETWEEN Operator

The Quarterly Review

It was time for the financial report. *"I need a list of all transactions that happened between October 1st and December 31st,"* the CFO requested. *"Oh, and only if they were between $100 and $500."*

I was tempted to use `>=` and `<=`, but those "Double Logic" filters are easy to misread.

The Quest: The Boundary Logic

SQL provides a dedicated keyword for ranges: `BETWEEN`. It is **inclusive**, meaning it includes the start and end values themselves.

The Implementation: The Double Target

Instead of writing `price >= 100 AND price <= 500`, we write:

-- Filtering for price and dates in ranges

SELECT *

FROM orders

WHERE price BETWEEN 100 AND 500

AND order_date BETWEEN '2025-10-01' AND '2025-12-31';

Why it's safer

**Readability**: It reads like plain English.

**Logic Safety**: You are much less likely to flip a `>` or `<` sign by accident.

The "Oops" Moment

I once forgot that `BETWEEN` includes the exact timestamps. If a transaction happened at exactly midnight on the end date, it might get skipped if I didn't handle the time format correctly.

**Pro Tip**: When using `BETWEEN` with dates, it's often safer to use `'2025-12-31 23:59:59'` to ensure you catch the very last minute of the year.

The Victory

The CFO got his report with zero "Missing" end-of-year transactions. Range logic is the backbone of all financial reporting, and `BETWEEN` is the professional's choice for precision.

Your Task for Today

Filter a numerical column using `BETWEEN`. Then, try to use it on a date column and see how it handles the boundaries.

*Day 12: Text Cleanup—Fundamental String Functions.*