Question { Genpact, 1509 }

What is the difference between UNIQUE and DISTINCT keywords in DBMS?

Answer

First we declare is as primary key and after group by we can get uniqu values.

CREATE TABLE Persons (
ID int NOT NULL,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Age int,
PRIMARY KEY (ID)
);

SELECT ID, LastName,FirstName
FROM Persons
GROUP BY ID, LastName,FirstName;