SQL CASE Statement Explained with Real-World Examples

Conditional logic is everywhere—from setting discounts to classifying users. SQL has a native way to handle this with the CASE statement.

In this quick guide, you’ll explore how to use CASE to implement branching logic in your queries. We’ll cover its two forms, show real-world use cases, and explain where and when to use it for best results.

Using SQL CASE in Practice

Simple comparison:

CASE grade
  WHEN 'A' THEN 'Excellent'
  WHEN 'B' THEN 'Good'
  ELSE 'Needs Work'
END

Conditional logic for prices:

CASE
  WHEN category = 'Shoes' THEN price * 0.85
  WHEN category = 'Gifts' AND price <= 50 THEN price * 0.5
  ELSE price
END

Employee bonus example:

CASE
  WHEN role = 'Manager' AND years >= 5 THEN salary * 0.1
  WHEN role = 'Developer' AND years >= 3 THEN salary * 0.08
  ELSE 0
END

Used in WHERE clause:

WHERE
  CASE
    WHEN status = 'active' THEN 1
    ELSE 0
  END = 1

FAQ

How does the CASE statement work in SQL?

It evaluates conditions in order and returns the result of the first match.

Can I use CASE in ORDER BY?

Yes. You can use it for sorting rows based on dynamic logic.

Is ELSE required?

No. But without it, unmatched conditions return NULL.

Can I nest CASE statements?

Yes. Nesting allows more complex logic handling in a single query.

Conclusion

The SQL CASE statement is powerful for applying conditional logic in queries—no external scripts or procedural code needed. It’s supported in all major databases and flexible enough for many use cases.

Read the full guide SQL CASE Statement: Definitive Guide.