Returns the result of the argument character expression after converting all the characters to uppercase.
Syntax
UPPER ( char_expression )
Notes
The argument to the function must be of type CHARACTER.
The result is of type CHARACTER.
If the argument expression evaluates to NULL, the result is NULL.
A char_expression and the result can contain multi‑byte characters. The uppercase conversion is determined by the case table in the convmap file. The default case table is BASIC.
Example
This example illustrates the UPPER function, returning columns from rows in the customer table where the last_name column, after being converted to uppercase, is equal to ‘SMITH':
SELECT *
FROM customer
WHERE UPPER (last_name) = 'SMITH' ;