It converts the alpha character values to upper case.
The return value has the same data type as the argument CHAR.

Syntax :

UPPER(Column/Expression)

Examples :

1.
SELECT
'oracle corporation' String,
UPPER('oracle corporation') Upper
FROM DUAL;

2.
SELECT Ename, UPPER('my information') Lower
FROM Emp;

3.
SELECT Ename, UPPER(Ename), LOWER(Ename)
FROM Emp
WHERE Job= 'MANAGER';

4.
SELECT 'The'||Ename||'" s Designation is '|| Job Employee
FROM  Emp
WHERE Job= UPPER('manager');


5.
SELECT Ename, Job
FROM Emp
WHERE Job=UPPER('Manager');

6.
SELECT Ename, Job, Sal, Sal*12
FROM Emp
WHERE Job= UPPER(LOWER('MANAGER'));

7.
SELECT UPPER('The '||Ename||'"s Basic salary is rupees'|| Sal)
FROM Emp
WHERE Job IN('MANAGER', UPPER('clerk'));
ORDER By Sal DESC;