UPPER returns char, with all letters uppercase. char can be any of the data types CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB. The return value is the same data type as char. The database sets the case of the characters based on the binary mapping defined for the underlying character set. For linguistic-sensitive uppercase, refer to NLS_UPPER.

See Also:

Appendix C in Oracle Database Globalization Support Guide for the collation derivation rules, which define the collation assigned to the character return value of UPPER


The following example returns each employee's last name in uppercase:

SELECT UPPER(last_name) "Uppercase"
   FROM employees;