unit CourseElectForm;

interface

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

type
  TCourseElect = class(TForm)
    GroupBox1: TGroupBox;
    GroupBox2: TGroupBox;
    GroupBox3: TGroupBox;
    Edit1: TEdit;
    Label1: TLabel;
    Edit2: TEdit;
    Label2: TLabel;
    Edit3: TEdit;
    Label3: TLabel;
    ADOQuery1: TADOQuery;
    ADOConnection1: TADOConnection;
    DataSource1: TDataSource;
    ADOQuery2: TADOQuery;
    DBGrid1: TDBGrid;
    DataSource2: TDataSource;
    Panel1: TPanel;
    DBGrid2: TDBGrid;
    Edit4: TEdit;
    Label4: TLabel;
    Edit5: TEdit;
    Label5: TLabel;
    Edit6: TEdit;
    Label6: TLabel;
    Edit7: TEdit;
    Label7: TLabel;
    BitBtn1: TBitBtn;
    BitBtn2: TBitBtn;
    BitBtn3: TBitBtn;
    BitBtn4: TBitBtn;
    ADOQuery3: TADOQuery;
    ADOCommand1: TADOCommand;
    procedure Edit1KeyPress(Sender: TObject; var Key: Char);
    procedure BitBtn1Click(Sender: TObject);
    procedure BitBtn2Click(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure BitBtn3Click(Sender: TObject);
    procedure BitBtn4Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    procedure listcourse(id:string);
  end;

var
  CourseElect: TCourseElect;
  id:string;//選課學生的學號
implementation

{$R *.dfm}
uses ScheduleForm;
//--------------輸入學號后回車，顯示學生信息及已經(jīng)選的課程----------------
procedure TCourseElect.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
if not (key in ['0'..'9',#8,#13]) then //該文本框中只能輸入數(shù)字
begin
 key:=#0;
 exit;
end;
//回車輸入，將在籍學生的信息顯示在文本框中
if key=#13 then
 begin
  id:=trim(edit1.Text);
  //清除上一次的數(shù)據(jù)
  edit2.Clear;
  edit3.Clear;
  adoquery2.Close;

  adoquery1.Close;
  adoquery1.SQL.Clear;
  adoquery1.SQL.Add('select a.姓名,b.班級名稱,a.學籍編號 from 學生信息 a,班級信息 b');
  adoquery1.SQL.Add('where (a.學號='''+id+''')and(a.班級編號=b.班級編號)');
  adoquery1.Open;
  if trim(adoquery1.FieldByName('學籍編號').AsString)='1' then
  begin
  edit2.Text:=trim(adoquery1.fieldbyname('姓名').AsString);
  edit3.Text:=trim(adoquery1.fieldbyname('班級名稱').AsString);
  listcourse(id); //列出已選課程
  //允許開始選課
  bitbtn2.Enabled:=true;
  bitbtn3.Enabled:=true;
  bitbtn4.Enabled:=true;
  end
  else
   begin
   //只有在籍學生才能選課
   showmessage('該生非在籍學生，不能選課');
   bitbtn2.Enabled:=false;
   bitbtn3.Enabled:=false;
   bitbtn4.Enabled:=false;
   id:='';
   end;
 end;

end;

//--------顯示學生已經(jīng)選的課程----------
procedure TCourseElect.listcourse(id: string);
begin
  //將符合選課條件的學生已經(jīng)選過的課程列在表中
  adoquery2.Close;
  adoquery2.SQL.Clear;
  adoquery2.SQL.Add('select a.學號,a.課序號,b.課程名稱,b.教師,b.開課系別,c.上課時間天,c.上課時間節(jié),c.上課地點');
  adoquery2.SQL.Add('from 選課表 a,課程信息 b,課程表 c');
  adoquery2.SQL.Add('where (a.學號='''+id+''')and(a.課序號=c.課序號)and(''200400000''+b.課程編號=a.課序號)');
  adoquery2.Open;
end;

//---------------課程查詢-------------------
procedure TCourseElect.BitBtn1Click(Sender: TObject);
var
sql:string;
begin
sql:='';
if trim(edit4.Text)<>'' then
 sql:=sql+'拼音碼 like ''%'+trim(edit4.Text)+'%'' AND ';
if trim(edit5.Text)<>'' then
 sql:=sql+'課程名稱 like ''%'+trim(edit5.Text)+'%'' AND ';
if trim(edit6.Text)<>'' then
 sql:=sql+'課程編號='''+trim(edit6.Text)+''' AND ';
if trim(edit7.Text)<>'' then
 sql:=sql+'課序號 like ''%'+trim(edit7.Text)+'%'' AND ';

sql:=copy(sql,1,length(sql)-4);
adoquery3.Filtered:=false;
adoquery3.Active:=false;
adoquery3.Filter:=sql;
adoquery3.Active:=true;
adoquery3.Filtered:=true;

end;

//-----------將選擇的課程添加到學生的選課表中--------------
procedure TCourseElect.BitBtn2Click(Sender: TObject);
var
num:string;
day,section:integer;
begin
//未選擇課程時，不允許提交
if adoquery3.RecordCount=0 then
 begin
  showmessage('請先選擇一門課程');
  exit;
 end;
num:=trim(dbgrid2.Fields[0].Text);//保存課序號

//判斷所選的課程是否已選和是否與其他已經(jīng)選的課程有時間沖突
adoquery1.Close;
adoquery1.SQL.Clear;
adoquery1.SQL.Add('select 上課時間天,上課時間節(jié) from 課程表');
adoquery1.SQL.Add('where 課程編號='''+dbgrid2.Fields[1].Text+'''');
adoquery1.Open;

while not adoquery1.Eof do
 begin
  day:=adoquery1.fieldbyname('上課時間天').AsInteger;
  section:=adoquery1.fieldbyname('上課時間節(jié)').AsInteger;
  adoquery2.First;
  while not adoquery2.Eof do
   begin
   //判斷課程是否已選
   if (trim(adoquery2.fieldbyname('課序號').AsString)=num) then
    begin
     showmessage('所選的課程：'+trim(adoquery2.fieldbyname('課程名稱').AsString)+' 已在課表中，請選擇其他課程');
     exit;
    end;
   //判斷課程是否與已選課程有時間沖突
   if (adoquery2.fieldbyname('上課時間天').AsInteger=day)and(adoquery2.fieldbyname('上課時間節(jié)').AsInteger=section) then
    begin
     showmessage('所選課程的上課時間與已選的 '+trim(adoquery2.fieldbyname('課程名稱').AsString)+' 沖突!');
     exit;
    end;
   adoquery2.Next;
   end;
  adoquery1.Next;
 end;
//選課
adocommand1.CommandText:='insert into 選課表([學號],[課序號]) values('''+id+''','''+trim(dbgrid2.Fields[0].Text)+''')';
adocommand1.Execute;
listcourse(id);//刷新數(shù)據(jù)表
end;


//-------------刪除已選課程-------------
procedure TCourseElect.BitBtn3Click(Sender: TObject);
begin
if application.MessageBox('確實刪除所選課程？','確定刪除',MB_OKCANCEL)=IDOK then
 begin
  adocommand1.CommandText:='delete from 選課表 where (學號='''+trim(dbgrid1.Fields[0].Text)+''')and(課序號='''+trim(dbgrid1.Fields[1].Text)+''')';
  adocommand1.Execute;
  listcourse(id);//刷現(xiàn)列表
 end;
end;

//--------------調(diào)用【課表查詢】窗體，顯示學生課表--------------
procedure TCourseElect.BitBtn4Click(Sender: TObject);
var
newform:TSchedule;
begin
  newform:=TSchedule.Create(application);
  newform.Caption:=edit2.Text+'同學課程表';
  newform.id:=id;
  //傳遞學號，姓名，班級等參數(shù)
  newform.Edit1.Text:=id;
  newform.Edit2.Text:=edit2.Text;
  newform.Edit3.Text:=edit3.Text;
  newform.GroupBox1.Enabled:=false;//不能再顯示他人的課程表
  //顯示課表
  newform.selrecord();
end;

procedure TCourseElect.FormClose(Sender: TObject;
  var Action: TCloseAction);
begin
action:=cafree;
end;

end.