SQL Server - autoincrement

how to add autoincrement column in MSSQl

ALTER TABLE test ADD idd SMALLINT AUTO_INCREMENT  PRIMARY KEY 

Try below code

alter table test
    add idd bigint identity( 1, 1 ) not null
go

If you want the particular column to be primary key just add PRIMARY KEY to my code as shown below

alter table test
    add idd bigint not null identity(1,1) primary key
go

AUTO_INCREMENT is a MySql keyword. For SQL you need to use IDENTITY like;

CREATE TABLE new_employees
(
id_num int IDENTITY(1,1),
fname varchar (20),
minit char(1),
lname varchar(30)
);

So in your case use it like;

ALTER TABLE test ADD idd SMALLINT IDENTITY(1,1) PRIMARY KEY 

Syntax for MySQL

By default, the starting value for AUTO_INCREMENT is 1, and it will increment by 1 for each new record.

CREATE TABLE Persons

(

P_Id int NOT NULL AUTO_INCREMENT,

FirstName varchar(255),

PRIMARY KEY (P_Id)

ALTER TABLE Persons AUTO_INCREMENT=100

Syntax for SQL Server

The following SQL statement defines the "P_Id" column to be an auto-increment primary key field in the "Persons" table:CREATE TABLE Persons

(

P_Id int PRIMARY KEY IDENTITY,

FirstName varchar(255),

)

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

By default, the starting value for IDENTITY is 1, and it will increment by 1 for each new record.

To specify that the "P_Id" column should start at value 10 and increment by 5, change the identity to IDENTITY(10,5).