学生管理系统Delphi7.0+SQL Sever

USE stdDB GO create trigger GrdGpaTri ON StdGrade FOR UPDATE AS if update(grd) begin case when(StdGrade.grd between 90 and 100) then begin update StdGrade set gpa = 4.0 end else when(StdGrade.grd between 85 and 89.5) begin update StdGrade set gpa = 3.7 end; if(grd between 82 and 84.5) begin update StdGrade set gpa = 3.3 end; if(grd between 78 and 81.5) begin update StdGrade set gpa = 3.0 end; if(grd>=75 and grd<=77.5) begin update StdGrade set gpa = 2.7 end; if(grd>=72 and grd<=74.5) begin update StdGrade set gpa = 2.3 end; if(grd>=68 and grd<=71.5) begin update StdGrade set gpa = 2.0 end; if(grd>=64 and grd<=67.5) begin update StdGrade set gpa = 1.5 end; if(grd>=60 and grd<=63.5) begin update StdGrade set gpa = 1.0 end; if(grd<60) begin update StdGrade set gpa = 0 end; end;