Distinct operator in SQL Query with examples

DISTINCT is used for fetch the distinct value of specific column in Oracle table.

Select distinct columnname, columnname from tablename;

Example
I want to see distinct dept no in employee tables.

Select distinct deptno from employee;


You can pass two column to fetch distinct value of two columns:

select distinct first_name,last_name from employee;


Count the distinct number:
Count the distinct department from employee tables

select count(distinct deptno) from employees;