对记录集的一个操作改如何实现？【问题有详细说明】

adodc1.recordsource = "select sum（奖学金),avg（奖学金),cdbl（sum（case when 奖学金> 0 then 1 else 0 end))/count（1) as 获得奖学金的人数比例 from student where 专业 ='" & text1.text & "'""

private sub command1_click（index as integer) 
dim rs as adodb.recordset, inttmp as integer, sngproportion as single
 
 select case index 
   case 0 
     adodc1.recordsource = "select * from student where 专业 = '" & text1.text & "'" 
   case 1 
     adodc1.recordsource = "select sum（奖学金) as sumscholarship, avg（奖学金) as avgscholarship from student where 专业 ='" & text1.text & "'"
     set rs = adodc1.recordset.activeconnection.ＥＸＥＣute （select sum（*) from student where 专业 = '" & text1.text & "'")
     inttmp = rs.fields（0)
     set rs = adodc1.recordset.activeconnection.ＥＸＥＣute （select sum（*) from student where 专业 = '" & text1.text & "' and 奖学金>0")
     sngproportion = rs.fields（0)
     sngproportion = （sngproportion / inttmp) * 100
     text2 = format（sngproportion, "standard") & "%"        
   case   2 
     adodc1.recordsource = "select * from student" 
 end   select 
 adodc1.refresh 
end sub