Here:
CREATE TABLE [dbo].[TestTable]
(
ID int IDENTITY(1,1) NOT NULL,
FirstName varchar(100) NULL,
CONSTRAINT [PK_TestTable] PRIMARY KEY CLUSTERED([ID] ASC)
)
OR
CREATE TABLE CUSTOMERS(
ID INT IDENTITY(1,1) NOT NULL,
NAME VARCHAR (20) NOT NULL,
AGE INT NOT NULL,
ADDRESS CHAR (25) ,
SALARY DECIMAL (18, 2),
PRIMARY KEY (ID)
);
Refer:
SQL - Primary Key[
^]
MSDN: CREATE TABLE (Transact-SQL)[
^]