bookdelete.pas

来自「图书管理系统。可以实现简单的图书管理」· PAS 代码 · 共 120 行

unit bookdelete;

interface

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

type
  TForm4 = class(TForm)
    RadioGroup1: TRadioGroup;
    BitBtn1: TBitBtn;
    BitBtn2: TBitBtn;
    Edit1: TEdit;
    Edit2: TEdit;
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    BitBtn3: TBitBtn;
    Edit3: TEdit;
    procedure BitBtn1Click(Sender: TObject);
    procedure BitBtn3Click(Sender: TObject);
    procedure BitBtn2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form4: TForm4;

implementation

{$R *.dfm}
 //定位按钮
procedure TForm4.BitBtn1Click(Sender: TObject);
 
begin
case radiogroup1.ItemIndex of
 0:
  BEGIN
  datamodule1.adoquery1.Close;
  datamodule1.adoquery1.sql.clear;
  datamodule1.adoquery1.sql.Add('select * from book1');
  datamodule1.adoquery1.open;
  Datamodule1.adoquery1.locate('书号',edit1.text,[locaseinsensitive,lopartialkey]);
  END;
 1:
 BEGIN
  datamodule1.adoquery1.Close;
  datamodule1.adoquery1.sql.clear;
  datamodule1.adoquery1.sql.Add('select borrow.借阅证号, book1.书号,book.*,book1.状态 from borrow,book,book1 ') ;
  datamodule1.adoquery1.sql.Add('where book.ISBN=book1.ISBN and book1.书号=borrow.书号 and 借阅证号=:s');
   datamodule1.adoquery1.parameters[0].value:=trim(edit2.text);
  datamodule1.adoquery1.open;
  
 END;
  
 2:
  BEGIN
  datamodule1.adoquery1.Close;
  datamodule1.adoquery1.sql.clear;
  datamodule1.adoquery1.sql.Add('SELECT  * from book WHERE ISBN='+''''+EDIT3.TEXT+'''');

  datamodule1.adoquery1.open;
  END;
end;
 end;
 //删除按钮
procedure TForm4.BitBtn3Click(Sender: TObject);
 var i:integer;
begin
 i:=messagedlg('是否真的要删除',mtwarning,[mbyes,mbno],0);
 if (i=6) and (radiogroup1.ItemIndex=0) then
   begin
     datamodule1.adoquery1.Close;
     datamodule1.adoquery1.sql.clear;
     datamodule1.adoquery1.sql.Add(' update  book set 数量=数量-1 where ISBN=(select ISBN from book1 where 书号=:s)');
     datamodule1.adoquery1.parameters[0].value:=trim(edit1.text);
      if  datamodule1.adoquery1.execsql>0 then
        begin
        datamodule1.adoquery1.Close;
        datamodule1.adoquery1.sql.clear;
        datamodule1.adoquery1.sql.Add(' delete from book1  where  书号=:s');
        datamodule1.adoquery1.parameters[0].value:=trim(edit1.text);
          if datamodule1.adoquery1.execsql>0 then
             begin
              showmessage('删除成功');
             end;
      end;
 end;

 if (i=6) and (radiogroup1.ItemIndex=2) then
 begin
     datamodule1.adoquery1.Close;
     datamodule1.adoquery1.sql.clear;
     datamodule1.adoquery1.sql.Add(' delete from   book1 where ISBN=:s');
     datamodule1.adoquery1.parameters[0].value:=trim(edit3.text);
     if datamodule1.adoquery1.execsql>0  then
      begin
        datamodule1.adoquery1.Close;
        datamodule1.adoquery1.sql.clear;
        datamodule1.adoquery1.sql.Add(' delete from book where ISBN=:s');
        datamodule1.adoquery1.parameters[0].value:=trim(edit3.text);
        if datamodule1.adoquery1.execsql>0  then
           showmessage('删除成功');
       end;
     
    end;
     

   end;
 
procedure TForm4.BitBtn2Click(Sender: TObject);
begin
 form4.close;
end;

end.