Identity column in SQL-SERVER

In this code we will learn about Identity column in SQL-SERVER which is automatically insert the value in identity column whenever new record gets inserted into the table.

--Create Student
if object_id('Student') is null
create table Student(id tinyint identity(1,1) ,Name varchar(20),Marks int)
--If we observe above Create table statement the Id column is identity column and its data type is tinyint.
We know that tinyint accepts 0 to 255 numbers range.
--insert data into Student table.
Declare @start int=1
while (@start<=256)
begin
insert into Student(Name,Marks) values('Rakesh',500)
set @start=@start+1
end
--In the above while loop we are trying to insert same record in 256 time. The identity column automatically supplied value. The 1-255 records gets inserted successfully.256 record get an error because of tinyint accepts 0-255 records only.
(1 row(s) affected)
(1 row(s) affected)