unit6.pas

成绩管理系统 主要实现：学生（学号

unit Unit6;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Grids, DBGrids, DB, ADODB;

type
  TForm6 = class(TForm)
    GroupBox1: TGroupBox;
    Label1: TLabel;
    Edit1: TEdit;
    Label2: TLabel;
    Edit2: TEdit;
    DBGrid1: TDBGrid;
    Label3: TLabel;
    Edit3: TEdit;
    Label4: TLabel;
    Button1: TButton;
    Button2: TButton;
    DataSource1: TDataSource;
    ADOQuery1: TADOQuery;
    Button3: TButton;
    procedure Button2Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form6: TForm6;

implementation
 uses Unit1;
{$R *.dfm}

procedure TForm6.Button2Click(Sender: TObject);
begin
form6.Close;
end;

procedure TForm6.Button1Click(Sender: TObject);
begin
   if(Edit1.Text='')then
       showmessage('学号不能够为空，请确认后重新输入！')
   else
       begin
          if (Edit2.Text ='')then
             showmessage('课程编号 不能够为空，请确认后重新输入！')
          else
            begin
            adoquery1.Close;
            adoquery1.SQL.Clear;
            adoquery1.SQL.Add('select stu_no from stud_score where stu_no='''+Edit1.Text+'''');
            adoquery1.Open;
            if adoquery1.RecordCount=0 then
                 showmessage('没有找到学号为'''+Edit1.Text+'''的成绩记录信息！')
             else 
                 begin
                      adoquery1.Close;
                      adoquery1.SQL.Clear;
                      adoquery1.SQL.Add('select Cour_no from stud_score where Cour_no='''+Edit2.Text+'''');
                      adoquery1.Open;
                      if (adoquery1.RecordCount=0)then
                           showmessage('没有找到课程号为'''+Edit2.Text+'''的成绩信息！')
                       else
                             begin
                                   adoquery1.Close;
                                   adoquery1.SQL.Clear;
                                   adoquery1.SQL.Add('select stu_no,Cour_no from stud_score where stu_no='''+Edit1.Text+'''and Cour_no='''+Edit2.Text+'''');
                                   adoquery1.Open;
                                   if adoquery1.RecordCount=0 then
                                           showmessage('不存在学号为'''+Edit1.Text+'''课程编号为'''+Edit2.Text+'''的成绩信息记录')
                                   else
                                        begin
                                             adoquery1.Close;
                                             adoquery1.SQL.Clear;
                                             adoquery1.SQL.Add('update stud_score set score='''+Edit3.Text+''' where stu_no='''+Edit1.Text+'''and Cour_no='''+Edit2.Text+'''');
                                             adoquery1.ExecSQL;
                                             showmessage('修改成功！');
                                             adoquery1.Close;
                                             adoquery1.SQL.Clear;
                                             adoquery1.SQL.Add('select stu_no as"学号",Cour_no as"班号",score as"分数" from stud_score where stu_no='''+Edit1.Text+'''and Cour_no='''+Edit2.Text+'''');
                                             adoquery1.Open;
                                        end
                             end
                   end
               end
         end
end;

procedure TForm6.Button3Click(Sender: TObject);
begin
    if Edit1.Text='' then
         showmessage('学号不能够为空')
    else
         begin
              adoquery1.Close;
              adoquery1.SQL.Clear;
              adoquery1.SQL.Add('select stu_no as"学号" ,Cour_no as"课程号" from stud_score where stu_no='''+Edit1.Text+'''');
              adoquery1.Open;
              if adoquery1.RecordCount=0 then
                  showmessage('不存在学号为'''+Edit1.Text+'''的成绩信息记录')
              else
                  begin
                     adoquery1.Close;
                     adoquery1.SQL.Clear;
                     adoquery1.SQL.Add('select stu_no as"学号",Cour_no as"课程号", score as"分数" from stud_score where stu_no='''+Edit1.Text+'''');
                     adoquery1.Open;
                  end
         end
end;

end.