LOWER

Description:

LOWER returns char, with all letters lowercase. char can be any of the datatypes CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB.
The return value is the same datatype as char.

Syntax:

LOWER(char)

Examples:

SELECT employee_id, last_name, department_id

FROM   employees

WHERE  last_name = 'higgins';

0 rows selected

The select statement displays the employee number, name, and department number of employee Higgins.

The WHERE clause specifies the employee name 

as higgins.

Because all the data in the EMPLOYEES table is stored in proper case, the name higgins does not find a match in the table,and no rows are selected.

SELECT employee_id, last_name, department_id

FROM   employees

WHERE  LOWER(last_name) = 'higgins';

The WHERE clause specifies that the employee name in the EMPLOYEES table is compared to higgins, converting the LAST_NAME column to lowercase for comparison purposes.

Because both names are now lowercase, a match is found and one row is selected.

SELECT first_name, job_id FROM EMPLOYEES
WHERE department_id = 60;

The original data from EMPLOYEES table.

SELECT LOWER(first_name),LOWER(job_id) FROM EMPLOYEES
WHERE department_id = 60;

The same data using LOWER function.