# CASE Expressions — MySQL

Source: https://www.geekswithgeeks.com/en/mysql/sql-case

> Inline if/else logic inside a query.

## CASE WHEN

`CASE` picks a value based on conditions, evaluated top to bottom — like if/elif/else inside SQL.

```sql
SELECT name, amount,
  CASE
    WHEN amount > 1500 THEN 'High'
    WHEN amount > 500 THEN 'Medium'
    ELSE 'Low'
  END AS tier
FROM orders;
```

Output:

```
name        | amount  | tier
Asha Rao    | 2000.00 | High
Rahul Mehta | 1300.00 | Medium
```

## CASE inside aggregates

`SUM(CASE WHEN status = 'paid' THEN amount ELSE 0 END)` is a common pattern for conditional totals in one pass.