unitstudent.pas

SQL2000跟课件学习的源代码 分享共同学习

unit UnitStudent;

interface

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

type
  TFormStudent = class(TForm)
    SpeedButton1: TSpeedButton;
    EditStuID: TDBEdit;
    SpeedButton2: TSpeedButton;
    EditStuName: TDBEdit;
    Label1: TLabel;
    CBoxSex: TDBComboBox;
    SpeedButton3: TSpeedButton;
    DateTimeBirthday: TDateTimePicker;
    SpeedButton4: TSpeedButton;
    DBLookupComboBox1: TDBLookupComboBox;
    SpeedButton5: TSpeedButton;
    EditTelePhone: TDBEdit;
    Label2: TLabel;
    TextCreditHour: TDBText;
    DBGrid1: TDBGrid;
    DBNavigator1: TDBNavigator;
    Label3: TLabel;
    EditPwd: TDBEdit;
    procedure FormShow(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure DateTimeBirthdayChange(Sender: TObject);
    procedure SpeedButton1Click(Sender: TObject);
  private
    { Private declarations }
    procedure QueryStudentAfterScroll(DataSet: TDataSet);
    procedure QueryStudentBeforePost(DataSet: TDataSet);
  public
    { Public declarations }
  end;

var
  FormStudent: TFormStudent;

implementation

uses UnitDM, UnitSearch;
var
  ConStr:     string;

{$R *.dfm}

procedure TFormStudent.FormShow(Sender: TObject);
begin
  CBoxSex.Items.Clear;  // 性别只能输入男或女
  CBoxSex.Items.Add('男');
  CBoxSex.Items.Add('女');
  DM_Data.TableClass.Open;  // 打开班级表
  with DM_Data.QueryStudent do begin
    AfterScroll := QueryStudentAfterScroll;  // 为QueryStudent动态设置AfterScroll事件
    BeforePost := QueryStudentBeforePost;    // 为QueryStudent动态设置BeforePost事件
    Open;     // 打开学生信息表
  end;
end;

procedure TFormStudent.FormClose(Sender: TObject;
  var Action: TCloseAction);
begin
  DM_Data.QueryStudent.AfterScroll := Nil;
  DM_Data.QueryStudent.BeforePost := Nil;
  DM_Data.QueryStudent.Close; // 关闭学生信息表
  DM_Data.TableClass.Close;   // 打开班级信息表
end;

procedure TFormStudent.QueryStudentAfterScroll(DataSet: TDataSet);
begin
  try
    if DataSet.FieldByName('Birthday').AsString='' then Exit;
    DateTimeBirthday.Date := DataSet.FieldByName('Birthday').AsDateTime;
  except
    DateTimeBirthday.Date := Date;
  end;
end;

procedure TFormStudent.QueryStudentBeforePost(DataSet: TDataSet);
begin
  try
    DateTimeBirthday.Time :=0;
    DataSet.FieldByName('Birthday').AsDateTime := DateTimeBirthday.DateTime;
  except

  end;
end;

procedure TFormStudent.DateTimeBirthdayChange(Sender: TObject);
begin
  DM_Data.QueryStudent.Edit;
  QueryStudentBeforePost(DM_Data.QueryStudent); // 将修改数据送入数据表
end;

procedure TFormStudent.SpeedButton1Click(Sender: TObject);
var
  SearchHint:   String;
begin
  Case (Sender As TSpeedButton).Tag of
    1:  SearchHint := '学号';
    2:  SearchHint := '姓名';
    3:  SearchHint := '出生年月';
    4:  SearchHint := '所在班级';
    5:  SearchHint := '联系电话';
  end;
  FormSearch.Caption := '请输入要查询的'+SearchHint;
  FormSearch.EditSearch.Text := '';
  // 显示输入查询内容对话框
  if FormSearch.ShowModal = mrNo then Exit;
  // 判断是否连接查询，即按多个字段设置查询条件
  if Not FormSearch.CheckBox1.Checked then
     ConStr := '';
  Case (Sender As TSpeedButton).Tag of
    1: if ConStr = '' then     // 为姓名设置查询条件
         ConStr := 'StudentID Like ''%'+FormSearch.EditSearch.Text+'%'''
       else
         ConStr := ConStr + 'and StudentID Like ''%'+FormSearch.EditSearch.Text+'%''';
    2: if ConStr = '' then    // 为姓名设置查询条件
         ConStr := 'StudentName Like ''%'+FormSearch.EditSearch.Text+'%'''
       else
         ConStr := ConStr + 'and StudentName Like ''%'+FormSearch.EditSearch.Text+'%''';
    3: if ConStr = '' then    // 为出生年月设置查询条件
         ConStr := 'Birthday = '''+FormSearch.EditSearch.Text+''''
//         ConStr := 'Birthday = cast('''+FormSearch.EditSearch.Text+''' As DateTime)'
       else
         ConStr := ConStr + 'and Birthday = '''+FormSearch.EditSearch.Text+'''';
    4: if ConStr = '' then   // 为所在班级设置查询条件
         ConStr := 'ClassID Like ''%'+FormSearch.EditSearch.Text+'%'''
       else
         ConStr := ConStr + 'and ClassID Like ''%'+FormSearch.EditSearch.Text+'%''';
    5: if ConStr = '' then  // 为联系电话设置查询条件
         ConStr := 'TelePhone Like ''%'+FormSearch.EditSearch.Text+'%'''
       else
         ConStr := ConStr + 'and TelePhone Like ''%'+FormSearch.EditSearch.Text+'%''';
  end;
  with DM_Data.QueryStudent do begin
    try
      Active := False;
      SQL.Clear;          // 动态生成SQL语句
      SQL.Add('SELECT *');
      SQL.Add('FROM Student');
      SQL.Add('where '+ConStr);
//      SQL.SaveToFile('c:\t.sql');
      Active := True;
    Except
    end;
    First;
  end;
end;

end.