bookfeequeryunit.pas

是一个Delphi的教材管理系统,内容很全面详细

unit BookFeeQueryUnit;

interface

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

type
  TfrmBookFeeQuery = class(TForm)
    GroupBox1: TGroupBox;
    RadioButton1: TRadioButton;
    RadioButton2: TRadioButton;
    GroupBox2: TGroupBox;
    Label1: TLabel;
    ComboBox1: TComboBox;
    BitBtn1: TBitBtn;
    BitBtn2: TBitBtn;
    DataSource1: TDataSource;
    DBGrid2: TDBGrid;
    DBGrid1: TDBGrid;
    procedure BitBtn1Click(Sender: TObject);
    procedure RadioButton1Click(Sender: TObject);
    procedure RadioButton2Click(Sender: TObject);
    procedure BitBtn2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure ComboBox1Change(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmBookFeeQuery: TfrmBookFeeQuery;
  StudentFee:TADOQuery;
  DepartmentFee:TADOQuery;
  QueryDS:TADODataSet;
implementation

uses DataModuleUnit;

{$R *.dfm}

procedure TfrmBookFeeQuery.BitBtn1Click(Sender: TObject);
begin
 close;
end;
//填充班级名到查询值中
procedure TfrmBookFeeQuery.RadioButton1Click(Sender: TObject);
var
  i:integer;
begin
   QueryDS.Close;
   dbgrid2.SendToBack;
   Combobox1.Clear;
   Combobox1.Enabled:=true;
   StudentFee:=TADOQuery.Create(nil);
   with StudentFee do
   begin
     Connection:=frmDataModule.Connection;
     SQL.Clear;
     SQL.Add('select className from classes');
     open;
     for i:=0 to RecordCount-1 do
     begin
       ComboBox1.Items.Add(Fields[0].Value);
       Next;
     end;
   end;
   label1.Caption:='选择查询班级名';
end;
 //填充院系名到查询值中
procedure TfrmBookFeeQuery.RadioButton2Click(Sender: TObject);
var
  i:integer;
begin
   QueryDS.Close;
   dbgrid1.SendToBack;
   Combobox1.Clear;
   Combobox1.Enabled:=true;
   DepartmentFee:=TADOQuery.Create(nil);
   with DepartmentFee do
   begin
     Connection:=frmDataModule.Connection;
     SQL.Clear;
     SQL.Add('select DepartmentName from Departments');
     open;
     for i:=0 to RecordCount-1 do
     begin
       ComboBox1.Items.Add(Fields[0].Value);
       Next;
     end;
   end;
   label1.Caption:='选择查询院系名';
end;

     //Parameters.CreateParameter('V',ftstring,pdinput,20,Combobox1.Text);等同下句
   //Parameters.FindParam('V').Value:=combobox1.Text;

 //执行查询
procedure TfrmBookFeeQuery.BitBtn2Click(Sender: TObject);
begin
  with QueryDS do
  begin
    close;
    Parameters.Clear;
    Parameters.CreateParameter('V',ftstring,pdinput,20,Combobox1.Text);
    if RadioButton1.Checked then
    begin
      //dbgrid1.Columns.
      CommandText:='select * from FeeHistory where [ClassName]=:V'
    end
    else
    begin
      CommandText:='select * from Departments where [DepartmentName]=:v';
    end;
   {Parameters.refresh;
    Parameters.findparame('v').Value := Combobox1.Text;
    active:=true;这样写可以不用创建参数}
    active:=true; 
  end;
end;



//初始化
procedure TfrmBookFeeQuery.FormCreate(Sender: TObject);
begin
  QueryDS:=TADODataSet.Create(nil);
  with QueryDS do
  begin
    Connection:=frmDataModule.Connection;
    CommandType:=cmdText;
  end;
  DataSource1.DataSet:=QueryDS;
  dbGrid1.DataSource:=DataSource1;
  dbGrid2.DataSource:=DataSource1;  
end;

procedure TfrmBookFeeQuery.ComboBox1Change(Sender: TObject);
begin
  QueryDS.Close;
end;

end.