请说出该程序段的功能。

  declare @e numeric(5,2)

  declare @ c1 int, @ c2 int, @ c3 int, @ c4 int

  set @ c1=0; set @ c2 =0; set @ c3=0; set @ c4=0

  declare xxx cursor

    for select 成绩 from score

  open xxx

  fetch xxx into @ c

  while @'@ fetch_status = 0

   begin

    if(@c ＞ =90) set @cl =@ e1 +1;

    else if( @ c ＞ =70) set @ c2 =@ c2 +1;

    else if(@ c＞ =60) set @ c3 =@ c3 +1;

    else set @ c4 = @ c4 + 1

    fetch from xxx into @ c

   end

  close xxx

  deallocate xxx

 print 优秀生人数：'+sb(@ c1，5)；

 print食好生人数：'+str(@ c2，5)；

 print及格生人数：'+str(@ c3，5)；

 print及格生人数：'+sh(@ c4，5)