2012-图书管理系统论文

BookID: string; strSql: string; strBookID: string; strDate:string; begin

strDate:=trim(edtToday.Text); if editreaderID.Text = '' then begin

ShowMessage('借书证号不能为空！'); editreaderID.SetFocus; Exit; end;

if editBookID.Text = '' then begin

ShowMessage('图书编号不能为空！'); editBookID.SetFocus; Exit; end;

BorrowBookID := Trim(editreaderID.Text); BookID := Trim(editBookID.Text);

if (BorrowBookID <> '') and (BookID <> '') then begin

QueryDelete.Close;

QueryDelete.SQL.Clear;

strSql := 'update 借出信息 set 借出状态=0 ,还书日期=''' + strdate + ''' where 图书编号 =' + BookID + ' and 借书证号=''' + BorrowBookID + ''' and 借出状态=1 ';

QueryDelete.SQL.Add(strSql); QueryDelete.ExecSQL;

if QueryDelete.RowsAffected > 0 then begin

ShowMessage('还书成功!'); //更新图书信息表在库标志

strBookID := Trim(editBookID.Text); DM.QueryReader.Close;

DM.QueryReader.SQL.Clear;

strSql := 'update 图书明细表 set 状态=''在库'' where 图书编号=' +

strBookID;

DM.QueryReader.SQL.Text := strSql; DM.QueryReader.ExecSQL; DM.QueryReader.Close; end else

ShowMessage('此书已还过!');

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end; end;

其它相关实现代码：

procedure TfrmReturnBook.editBookIDKeyPress(Sender: TObject; var Key: Char); begin

if Key = #13 then begin

if ViewBook(editBookID.Text) = false then begin

ShowMessage('没有此书, 请重新选择！'); Exit; end;

DM.QueryBook.Filtered := false;

DM.QueryBook.Filter := '图书编号=''' + editBookID.Text + ''''; DM.QueryBook.Filtered := true; edtToday.Text:=datetostr(date); end; end;

procedure TfrmReturnBook.editreaderIDKeyPress(Sender: TObject; var Key: Char); begin

if Key = #13 then begin

ADOQueryReturn.Close;

ADOQueryReturn.SQL.Clear;

ADOQueryReturn.SQL.Add(' select 借出日期 from 借出信息 where 借书证号=''' + editreaderID.Text + ''''); ADOQueryReturn.ExecSQL;

ADOQueryReturn.Active := true;

if ADOQueryReturn.RecordCount > 0 then

DBEdit1.Text := ADOQueryReturn.fieldbyname('借出日期').AsString; edtOwnDays.Text:= inttostr(Daysbetween(date,strtoDate(dbedit1.Text))); if daysbetween(date,strtoDate(dbedit1.Text)) >30 then edtOwnDays.Font.Color :=clRed;

label12.Caption:='您超期了,请下次及时归还！'; end; end;

function TfrmReturnBook.ViewBook(BookID: string): boolean; var Query: TADOQuery; begin

Query := TADOQuery.Create(self);

Query.Connection := DM.ADOConnection1;

Query.SQL.Add('select * from 图书明细表 where 图书编号=:id');

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Query.Parameters.ParamByName('ID').Value := BookID; Query.Open;

if Query.RecordCount = 0 then begin

Result := false; ; Exit; end else

Result := true; end;

4.2.6 新书入库

本模块主要实现的是管理员对新书的入库管理，打 * 号的是必填项目，置空会有信息提示该项不能为空，如图4-8所示：

图4-8 新书入库界面

确定按钮代码：

procedure TfrmNewBook.Button1Click(Sender: TObject); begin

if Edit2.Text = '' then begin

ShowMessage('图书名不能为空！'); Edit2.SetFocus; Exit; end;

if Edit1.Text = '' then begin

ShowMessage('图书编号不能为空！'); Edit1.SetFocus; Exit; end;

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if Edit2.Text = '' then begin

ShowMessage('图书名不能为空！'); Edit2.SetFocus; Exit; end;

if Edit3.Text = '' then begin

ShowMessage('作者不能为空！'); Edit3.SetFocus; Exit; end;

if Edit5.Text = '' then begin

ShowMessage('出版社不能为空！'); Edit5.SetFocus; Exit; end;

if Edit4.Text = '' then begin

ShowMessage('售价不能为空！'); Edit4.SetFocus; Exit; end;

if Edit7.Text = '' then begin

ShowMessage('出版日期不能为空！'); Edit7.SetFocus; Exit; end;

ADOQuery1.Close;

ADOQuery1.SQL.Clear;

ADOQuery1.SQL.Add('select * from 图书明细表 where 图书编号=:A '); ADOQuery1.Parameters.ParamByName('A').Value := Edit1.Text; ADOQuery1.Open;

if ADOQuery1.RecordCount > 0 then begin

ShowMessage('该书已存在！'); Edit2.Text := ''; Edit1.Text := ''; Edit3.Text := ''; Edit4.Text := ''; Edit5.Text := ''; Edit6.Text := '';

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