sql unique values in column code example

Example 1: DISTINCT SQL

SELECT DISTINCT column1, column1, ..... FROM TABLE
/*DISTINCT WILL NOT SELECT THE SAME VALUES IN SAME COLUMN*/

Example 2: unique element in sql

DISTINCT
- select distinct * from employees; ==> retrieves any row if it has at
least a single unique column.
- select distinct first_name from employees; ==> retrieves unique names
from table. (removes duplicates)
- select distinct count(*) from employees; retrieve number of unique rows
if any row has at least a single unique data.