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±íÃ÷ users Óû§±í
×Ö¶Î accountnum  varchar(50) --±íʾÕ˺Å
        password     varchar(50) --±íʾÃÜÂë
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create proc use_login
(
@accountnum varchar(50),
@password varchar(50),
@message  varchar(50) output

as
  if exists(select * from users where accountnum=@accountnum and  password=@password)
   set @message='µÇ¼³É¹¦'
 else  if  exists(select * from users where accountnum=@accountnum )
   set @message='ÃÜÂë´íÎó'
 else if exists(select * from users where password=@password)
  set @message='Óû§Ãû´íÎó'
else
  set @message='Óû§ÃûºÍÃÜÂë¶¼´íÎó'
declare @msg as varchar(50)
exec use_login 'text','text',@msg output
print @msg
×¢²á´æ´¢¹ý³Ì
create proc use_registration
(
@accountnum varchar(50),
@password varchar(50),
@message  varchar(50) output
)
as
  if exists(select * from users where accountnum=@accountnum)
   set @message='¸ÃÓû§ÒѾ­´æÔÚ'
 else
    begin
     insert into users values(@accountnum,@password)
     set @message='¹§Ï²Äú£¬¿ÉÒÔ×¢²á¸ÃÓû§'
  end 
  declare  @msg as varchar(50)
 exec use_registration 'text','text',@msg output
print @msg
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