create table sales(
id int primary key,
item varchar(30),
target_reached bit default 0 not null,
sales_amt decimal(10,2),
entrydate datetime default getdate(),
added_sales decimal(10,2))

drop table sales

--alter
alter table sales add payment_amt decimal(10,2)

alter table sales drop column payment_amt

alter table sales alter column payment_amt int

alter table sales alter column payment_amt int not null

alter table sales alter column payment_amt int not null

alter table sales drop constraint primary key

select * from sales