Converts text to uppercase.
UPPER(<text>)
Makes every letter uppercase; other characters don't change. Its mirror function is LOWER, which makes letters lowercase. Often used to display codes, abbreviations or headings consistently, or to compare text regardless of case.
employees
| name | department | salary | bonus | phone |
|---|---|---|---|---|
| Emma | backend | 1200 | 300 | +44 7700 900123 |
| Liam | backend | 1000 | NULL | NULL |
| Olivia | frontend | 1350 | 150 | +44 7700 900456 |
| Noah | frontend | 950 | NULL | +44 7700 900789 |
| Sophia | design | 1200 | 200 | NULL |
These tables already exist in the sandbox — the examples below use them. Want to try this in your own database? Copy the SQL.
| upper_case |
|---|
| HELLO, SQL |
| name | department |
|---|---|
| Emma | BACKEND |
| Liam | BACKEND |
| Olivia | FRONTEND |
| Noah | FRONTEND |
| Sophia | DESIGN |
| name | department |
|---|---|
| Emma | backend |
| Liam | backend |
Both sides in uppercase — and backend in the table matches Backend in the query.
Bring both sides to the same case: UPPER(department) = 'Backend' finds nobody, because the left side is all uppercase.
An index on an expression only helps that same expression: an index on LOWER(name) won't speed up a query with UPPER(name). Pick one case for all your searches.
Not every letter has an obvious uppercase counterpart: UPPER('straße') gives STRAẞE with the rare capital ß, not STRASSE.