存储过程代码阅读

create procedure dbauthenticate
(
  @username varchar(100),
  @password varchar(100)
)
as
declare @id int
declare @actualpassword varchar(100)
select @id=identitycol,@actualpassword=u_password from userlist where u_username=@username
if @id is not null
  if @password=@actualpassword
    return @id
  else
    return -2
else
  return -1

---

create procedure dbregister
(
 @username varchar(100),
 @password varchar(100)
)
as
if exists(select u_id from userlist where u_username=@username)
   return -1
else
   insert userlist (u_username,u_password) values (@username,@password)
   return @@identity