unit7.pas

本例是用delphi开发的学生与课程信息管理系统

unit Unit7;

interface

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

type
  TFormcou_sel = class(TForm)
    Querycou_sel: TQuery;
    DataSourcecou_sel: TDataSource;
    DBGridcou_sel: TDBGrid;
    GroupBox1: TGroupBox;
    Label1: TLabel;
    Editkey_set: TEdit;
    ComboBoxkey: TComboBox;
    Label2: TLabel;
    Button1: TButton;
    Button2: TButton;
    Label3: TLabel;
    Button3: TButton;
    Button4: TButton;
    Button5: TButton;
    Button6: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure ComboBoxkeyChange(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Formcou_sel: TFormcou_sel;

implementation

{$R *.dfm}

procedure TFormcou_sel.Button1Click(Sender: TObject);
 var
  key,key_set:string;
begin
 key:=comboboxkey.text;
 key_set:=editkey_set.text;
 if(key='')and(key_set='')then
   with querycou_sel do
     begin
       close;
       sql.Clear;
       sql.Add('select * from course order by cno');
       prepare;
       open ;
     end
 else if(key<>'')and(key_set='')then
     showmessage('请输入''关键字设置''信息！') 
 else if(key='')and(key_set<>'')then
     showmessage('请选择''查询关键字选择''信息！')
 else
   begin
     key_set:=key_set+'%';
     if key='cno'then
      begin
       with querycou_sel do
         begin
           close;
           sql.Clear;
           sql.Add('select * from course where cno like :key_setname');
           sql.add('order by cno');
           parambyname('key_setname').AsString:=key_set;
           prepare;
           open;
         end;

       end
      else if key='cname'then
       with querycou_sel  do
         begin
           close;
           sql.clear;
           sql.Add('select * from course where cname like :key_setname');

           sql.add('order by cno');
           parambyname('key_setname').AsString:='%'+key_set+'%';
           prepare;
           open;
         end
     else if key='sem'then
       with querycou_sel do
         begin
           close;
           sql.Clear;
           sql.Add('select * from course where sem like :key_setname');
           sql.add('order by cno');
           parambyname('key_setname').AsString:=key_set;
           prepare;
           open;
         end
     else if key='cbook'then
       with querycou_sel do
        begin
         close;
         sql.clear;
         sql.add('select * from course where cbook like :key_setname');
         sql.add('order by cno');
         parambyname('key_setname').asstring:='%'+key_set+'%';
         prepare;
         open;
        end
     else if key='sdep'then
       with querycou_sel do
         begin
           close;
           sql.Clear;
           sql.Add('select * from student where sdep like :key_setname');
           sql.add('order by cno');
           parambyname('key_setname').AsString:=key_set;
           prepare;
           open;
         end;
      end;

end;

procedure TFormcou_sel.Button2Click(Sender: TObject);
begin
  close;
end;

procedure TFormcou_sel.ComboBoxkeyChange(Sender: TObject);
begin
  editkey_set.text:='';
end;

end.