DISTINCT

The SQL DISTINCT keyword is used in conjunction with SELECT statement to eliminate all the duplicate records and fetching only unique records.
There may be a situation when you have multiple duplicate records in a table. While fetching such records, it makes more sense to fetch only unique records instead of fetching duplicate records.

The basic syntax is as follows:

SELECT DISTINCT Column_Name(s) FROM Table_Name WHERE Conditions

Syntax For SQL:

SELECT DISTINCTDept_id FROM Employee

Employee
Emp_id	Name	Surname	Salary	Dept_id
1	Rajesh	Khanna	45000	2
2	Sneha	Gupta	55000	4
3	Sandeep	Nehte	95000	1
4	Kirti	Patil	25000	3
5	Nilesh	Jadhav	45000	3
6	Dipesh	Das	35000	5
7	Kailash	Rane	62000	1
8	Kavita	Deshpande	48000	3
9	Sanjay	Datt	50000	3
10	Shruti	Hasan	78000	1

After Execute: 

Dept_id

2

4

1

3

5