unit5.pas

本系统为学生管理系统,可实现选课和退选

unit Unit5;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Buttons, DB, DBTables, Menus, ComCtrls, ToolWin,
  Grids, DBGrids, ImgList;

type
  TForm5 = class(TForm)
    GroupBox3: TGroupBox;
    ListBox1: TListBox;
    ListBox2: TListBox;
    GroupBox4: TGroupBox;
    Label22: TLabel;
    ComboBox3: TComboBox;
    ComboBox4: TComboBox;
    Edit3: TEdit;
    GroupBox5: TGroupBox;
    Table1: TTable;
    GroupBox1: TGroupBox;
    SpeedButton2: TSpeedButton;
    SpeedButton1: TSpeedButton;
    Button3: TButton;
    Button6: TButton;
    GroupBox6: TGroupBox;
    ComboBox1: TComboBox;
    Button7: TButton;
    GroupBox8: TGroupBox;
    DBGrid1: TDBGrid;
    Query1: TQuery;
    DataSource1: TDataSource;
    ListBox3: TListBox;
    Memo1: TMemo;
    ImageList1: TImageList;
    Button1: TButton;
    Button2: TButton;
    Button5: TButton;
    Button4: TButton;

    procedure SpeedButton2Click(Sender: TObject);
    procedure SpeedButton1Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Button6Click(Sender: TObject);
    procedure Button7Click(Sender: TObject);





    procedure ToolButton2Click(Sender: TObject);

    procedure ToolButton6Click(Sender: TObject);
    procedure ToolButton3Click(Sender: TObject);
    procedure ToolButton5Click(Sender: TObject);
//    procedure ToolButton7Click(Sender: TObject);
    procedure ComboBox1Change(Sender: TObject);


//    procedure N17Click(Sender: TObject);
    procedure ToolButton4Click(Sender: TObject);
    procedure N11Click(Sender: TObject);
    procedure ListBox3Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);

    procedure Button5Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);







  private
    { Private declarations }
  public
    { Public declarations }

  end;

var
  Form5: TForm5;

   str1:string;
implementation

uses Unit6,Unit12, Unit13;

{$R *.dfm}



procedure TForm5.SpeedButton2Click(Sender: TObject);
begin

 if listbox2.Count>4 then
    showmessage('已不能再添加表')
  else
  try
    listbox2.Items.Add(listbox1.Items[listbox1.itemindex]);
    listbox1.DeleteSelected;
    button3.Visible:=true;
  except
    showmessage('请选择表项');
  end;
end;

procedure TForm5.SpeedButton1Click(Sender: TObject);
begin
try

    listbox1.Items.Add(listbox2.Items[listbox2.itemindex]);
    listbox2.DeleteSelected;
    button3.Visible:=true;
except
    showmessage('请选择表项')
end;
 end;
procedure TForm5.Button3Click(Sender: TObject);
var i,j:integer;
begin

        try
        for i:=0 to listbox2.Count-1 do
        begin

                table1.close;
                table1.open;
                table1.Active:=false;
                table1.TableName:=' ';
                table1.DatabaseName:='lin';
                table1.TableName:=listbox2.Items[i];
                table1.Active:=true;
                for j:=0 to table1.FieldCount-1 do
                begin
                 combobox3.Items.Add(listbox2.Items[i]+'.'+table1.Fields[j].FieldName);

                end;

        end;
        if listbox2.Count>=2 then
                button4.Enabled:=true
        else
        button4.Enabled:=false;
        str1:=listbox2.Items[0];
        if listbox2.Count-1 >0 then
        for i:=1 to listbox2.Count-1 do
            str1:=str1+','+listbox2.Items[i];

            //toolbutton3.Enabled:=true;
            groupbox4.Enabled:=true;
            button7.Enabled:=false;
            combobox1.Enabled:=false;

         //   toolbutton5.Enabled:=true;
            

        except
                showmessage('未正确选择表');
        end;
end;

procedure TForm5.FormCreate(Sender: TObject);

begin
        memo1.text:='';
        listbox1.Clear;
        groupbox3.enabled:=false;
      //  toolbutton1.Enabled:=false;
        button2.Enabled:=false;
        button4.Enabled:=false;
    //    toolbutton3.Enabled:=false;
     //   toolbutton5.Enabled:=false ;
//        toolbutton7.Enabled:=false;
         listbox1.Clear;
        button3.Visible:=false;
        groupbox4.Enabled:=false;
        groupbox6.Enabled:=false;

end;

procedure TForm5.Button6Click(Sender: TObject);
begin
if memo1.text<>'' then
memo1.text:=memo1.text+' ';
memo1.text:=memo1.Text+' '+combobox3.Text+combobox4.Text+''''+edit3.Text+'''';
groupbox6.Enabled:=true;
button2.Enabled:=true;
combobox1.Enabled:=true;
button7.Enabled:=true;
end;

procedure TForm5.Button7Click(Sender: TObject);
begin
memo1.Text:=memo1.Text+' '+combobox1.text;
 button7.Enabled:=false;
end;









procedure TForm5.ToolButton2Click(Sender: TObject);
begin
   Form6:=TForm6.create(self);
    Form6.Show;
end;



procedure TForm5.ToolButton6Click(Sender: TObject);
begin
Form5.Close;
end;

procedure TForm5.ToolButton3Click(Sender: TObject);
begin

 form13.Memo1.text:='*';
 button2.Enabled:=false;
 groupbox4.Enabled:=true;
 groupbox6.Enabled:=true;
 combobox3.Enabled:=true;
 combobox4.Enabled:=true;
 button6.Enabled:=true;
end;

procedure TForm5.ToolButton5Click(Sender: TObject);
begin
form13:=tform13.Create(self);
form13.Show;
if form13.Memo1.Text<>''   then
//toolbutton1.Enabled:=true;
button1.Enabled:=false;
end;

{procedure TForm5.ToolButton7Click(Sender: TObject);
begin

if listbox3.items.Text ='' then begin
showmessage('对不起不能保存空的!');
exit;
end;
if savedialog1.Execute then begin
try
   listbox3.Items.SaveToFile(savedialog1.FileName);
   showmessage('保存成功');
except
        showmessage( '保存失败');
end;
end;
end;       }
procedure TForm5.ComboBox1Change(Sender: TObject);
begin
button7.Enabled:=true;
end;



{procedure TForm5.N17Click(Sender: TObject);
begin
if opendialog1.Execute then begin
try
        listbox3.clear;
   listbox3.Items.LoadFromFile(opendialog1.FileName);
   showmessage('加载成功');
except
        showmessage( '加载失败');
end;
end;
end;}

procedure TForm5.ToolButton4Click(Sender: TObject);
begin
memo1.Text:=' ';
button2.Enabled:=true;
end;

procedure TForm5.N11Click(Sender: TObject);
begin
query1.Close;
query1.sql.Clear;
try


       memo1.text:=listbox3.Items[listbox3.Itemindex];
         query1.SQL.Add(memo1.Text);
         query1.open;
except
        showmessage('请选择历史条件');
end;
memo1.Text:='';
end;

procedure TForm5.ListBox3Click(Sender: TObject);
begin
//toolbutton1.Enabled:=true;
end;

procedure TForm5.Button1Click(Sender: TObject);
begin
memo1.text:='';
form13.Memo1.text:='';
form6.Memo1.text:='';
groupbox3.Enabled:=true;
groupbox3.Enabled:=true;
listbox1.Clear;
listbox2.Clear;
listbox1.items.Add('student');
listbox1.items.Add('course');
listbox1.items.Add('sc');
listbox1.items.Add('dept');
button2.Enabled:=false;
button4.Enabled:=true;
end;

procedure TForm5.Button2Click(Sender: TObject);
var s1,s2:string;
begin

s1:='';
s2:='';
if memo1.Text='' then
        s2:=' '
else
        s2:='and';
if form6.Memo1.text<>''  then
    memo1.text:=memo1.text+' '+s2+' '+form6.Memo1.text;
if (memo1.text='') then
        s1:=' '
else
        s1:='where';

memo1.Text:='select'+' '+'*'{form13.Memo1.text}+' '+'from'+' '+str1+' '+s1+memo1.Text;
query1.sql.Clear;
try
query1.SQL.Assign(memo1.Lines);
except
        showmessage('查询语句有错');
        memo1.Text:=' '
end;
query1.Open;
groupbox3.Enabled:=false;
groupbox4.Enabled:=false;
groupbox6.Enabled:=false;
button4.Enabled:=false;
//toolbutton3.Enabled:=false;
//toolbutton8.Enabled:=true;
listbox1.Clear;
listbox2.Clear;
listbox3.Items.add(memo1.Text);
//showmessage('设置条件查询请先按设置条件按纽');
//toolbutton1.Enabled:=false;
button7.Enabled:=false;
combobox1.Enabled:=false;
 combobox4.Enabled:=false;
 combobox3.Enabled:=false;
 button6.Enabled:=false;
memo1.Clear;
end;

procedure TForm5.Button5Click(Sender: TObject);
begin
form5.Close;
end;

procedure TForm5.Button4Click(Sender: TObject);
begin
Form6:=TForm6.create(self);
form6.Show;
combobox3.Enabled:=true;
combobox4.Enabled:=true;
button6.Enabled:=true;
end;

end.