Identity Column in sql

Identity (or AutoNumber) is a column that automatically generates numeric values. A start and increment value can be set, but most DBA leave these at 1. A GUID column also generates numbers; the value of this cannot be controlled. Identity/GUID columns do not need to be indexed

An identity column is a numeric column in a table that is automatically populated with an integer value each time a row is inserted. Identity columns are often defined as integer columns, but they can also be declared as a bigint, smallint, tinyint, or numeric or decimal as long as the scale is 0

Example of Identity column in SQL

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

We can also cusmized increament value in SQL

below is sntext for this :

IDENTITY (data_type [ , seed , increment ] ) AS column_name


Seed: Starting value of a column. 
      Default value is 1.

Here the example of Identity column in sql

USE DeveloperIndian;
GO
SELECT IDENTITY(int, 90000, 1) AS ProductId,
Name AS pd_name,
ProductNumber,
ListPrice
INTO DeveloperIndian.SpecialProduct
FROM DeveloperIndian.Product

-- Display new table
SELECT * FROM DeveloperIndian.SpecialProduct;