The MS SQL Server DISTINCT keyword is used in conjunction with the 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.
Syntax
Following is the basic syntax of the DISTINCT keyword to eliminate duplicate records.
SELECT DISTINCT column1, column2,.....columnN
FROM table_name
WHERE [condition]
Example
Consider the CUSTOMERS table having the following records.
ID NAME AGE ADDRESS SALARY
1 Ramesh 32 Ahmedabad 2000.00
2 Khilan 25 Delhi 1500.00
3 kaushik 23 Kota 2000.00
4 Chaitali 25 Mumbai 6500.00
5 Hardik 27 Bhopal 8500.00
6 Komal 22 MP 4500.00
7 Muffy 24 Indore 10000.00
Let us see how the following SELECT query returns duplicate salary records.
SELECT SALARY FROM CUSTOMERS
ORDER BY SALARY
The above command will produce the following output where salary 2000 comes twice which is a duplicate record from the original table.
SALARY
1500.00
2000.00
2000.00
4500.00
6500.00
8500.00
10000.00
Let us now use the DISTINCT keyword with the above SELECT query and see the result.
SELECT DISTINCT SALARY FROM CUSTOMERS
ORDER BY SALARY
The above command produces the following output where we do not have any duplicate entry.
SALARY
1500.00
2000.00
4500.00
6500.00
8500.00
10000.00
