create procedure draw 
    @err varchar(10) output
as
begin

declare
@itcode NVARCHAR(50),
@id int

select * from ticketLog where itcode = @itcode
if @@ROWCOUNT = 0
  select top 1 @id=id from ticket where allSum>0 order by newid()
  if @@ROWCOUNT = 0
        begin
            set @err='notTicket'
            return (1)
        end
  else
    update ticket set allSum=allSum-1 where id=@id
    insert into ticketLog (itcode,ticketID,dateTime) values(@itcode,@id,GETDATE())
    select * from ticket where id = @id //这里要返回成功后的票务信息
  end
else
    begin
        set @err='repeat'
        return (1)
    end
end

end 
go

declare @err varchar(10)
exec draw @err output
select @err

create procedure draw  
as 
begin 

declare 
@itcode NVARCHAR(50), 
@id int 

select * from ticketLog where itcode = @itcode 
if @@ROWCOUNT = 0 
  select top 1 @id=id from ticket where allSum>0 order by newid() 
  if @@ROWCOUNT = 0 
    return 'notTicket'--//怎么返回异常呢？ 
  else 
    begin--加上
    update ticket set allSum=allSum-1 where id=@id 
    insert into ticketLog (itcode,ticketID,dateTime) values(@itcode,@id,GETDATE()) 
    select * from ticket where id = @id --//这里要返回成功后的票务信息 
  end 
else 
  return 'repeat'--//怎么返回异常呢？ 
end