新建视图，修改视图，删除视图（用到的表和上一个博文的表一样）

create view  vw_StudentScore   

 as    
select
 sName,
 sAge,
 case
   when english IS null then '缺考'
   else CONVERT(varchar(50),math)
   end as english,
   是否报考=
      case
       when scoreId IS null then '未报考'
       else '已报考'
      end,
   是否合格=
      case
        when english>=60 and math>=60 then '合格'
        else '不合格'
      end 
    from Student
    left join Score
    on Score.studentId=Student.sId       
    

    select * from  vw_StudentScore   

    select * from Student
    
    update Student set sName='山西关羽' where sName='关羽'
  
    drop view vw_StudentScore   
  
  ------------------------------------------------------------------------
  create view vw2
  as
  select sName,
  case
   when sAge>13 and sAge<16 then'豆蔻年华'
   when sAge>50 then 'oldman'
   else '青少年'
   end as '状态'
  from Student         
  

  select * from vw2

  drop view vw2