Auto increment primary key in SQL Server Management Studio 2012

CREATE TABLE Persons (
Personid int IDENTITY(1,1) PRIMARY KEY,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Age int
);


The MS SQL Server uses the IDENTITY keyword to perform an auto-increment feature.

In the example above, the starting value for IDENTITY is 1, and it will increment by 1 for each new record.

Tip: To specify that the "Personid" column should start at value 10 and increment by 5, change it to IDENTITY(10,5).

To insert a new record into the "Persons" table, we will NOT have to specify a value for the "Personid" column (a unique value will be added automatically):

Make sure that the Key column's datatype is `int` and then setting identity manually, as image shows

![enter image description here][1]

Or **just run this code**

-- ID is the name of the [to be] identity column
ALTER TABLE [yourTable] DROP COLUMN ID
ALTER TABLE [yourTable] ADD ID INT IDENTITY(1,1)

the code will run, if `ID` is not the only column in the table


[1]:

*image reference fifo's*

You could do the following: New Table Creation:

-- create new table with Column ID which is Primary Key and Auto Increment --

CREATE TABLE titles(
id INT NOT NULL IDENTITY(1,1) PRIMARY KEY, --Primary Key with Auto-Increment --
keyword VARCHAR(260),
status VARCHAR(10),
);

If you Table Already exists and need to make the changes to ID column to be auto-increment and Primary key, then see below:

ALTER TABLE table DROP COLUMN id; // drop the existing ID in the table
ALTER TABLE table ADD id int IDENTITY(1, 1) NOT NULL; // add new column ID with auto-increment
ALTER TABLE table ADD CONSTRAINT PK_ident_test PRIMARY KEY CLUSTERED (id); // make it primary key