unit3.pas

使用delphi编写的图书管理系统：实现查询

unit Unit3;

interface

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

type
  Tcjts = class(TForm)
    DataSource1: TDataSource;
    ADOQuery1: TADOQuery;
    GroupBox1: TGroupBox;
    ComboBox1: TComboBox;
    Label1: TLabel;
    Label2: TLabel;
    Edit1: TEdit;
    BitBtn1: TBitBtn;
    BitBtn2: TBitBtn;
    DBGrid1: TDBGrid;
    Label3: TLabel;
    procedure BitBtn2Click(Sender: TObject);
    procedure ComboBox1Change(Sender: TObject);
    procedure BitBtn1Click(Sender: TObject);

  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  cjts: Tcjts;

implementation

{$R *.dfm}

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


procedure Tcjts.ComboBox1Change(Sender: TObject);
begin
edit1.Text:=''
end;

procedure Tcjts.BitBtn1Click(Sender: TObject);
var g,gz,j,s:string;
begin
g:=trim(combobox1.Text);
gz:=trim(edit1.Text);
j:='借出';
s:='在库';
if(g='')and(gz='')then
with adoquery1 do
begin
close;
sql.Clear;
sql.Add('select tsbm.sh,tsbm.sm,dzmc.jszh,dzmc.xm,tsjy.jcrq');
sql.add('from tsbm,dzmc,tsjy');
sql.Add('where (tsbm.sh=tsjy.sh)and (dzmc.jszh=tsjy.jszh)and(tsjy.jcbz=:jn)');
sql.Add('order by tsbm.sh');
Parameters.ParamByName('jn').Value:=j;
prepared;
open;
end
else
if(g<>'')and (gz='') then
showmessage('请输入"查询的关键字"信息！')
else
if (g='') and (gz<>'') then
showmessage('请选择"关键字设置"信息')
else
   begin
    gz:=gz+'%';
    if g='图书编号' then
     with adoquery1 do
     begin
     Close;
     SQL.Clear;
     sql.Add('select tsbm.sh,tsbm.sm,dzmc.jszh,dzmc.xm,tsjy.jcrq');
     sql.add('from tsbm,dzmc,tsjy');
      sql.Add('where (tsbm.sh=tsjy.sh)and (dzmc.jszh=tsjy.jszh)and(tsjy.sh like :name) and(tsjy.jcbz=:jn)');
     sql.Add('order by tsbm.sh');
     Parameters.ParamByName('jn').Value:=j;
      Parameters.ParamByName('name').Value:=gz;
     Prepared;
     Open;
     end
    else
    if g='图书名称' then
     with adoquery1 do
      begin
      Close;
      SQL.Clear;
      sql.Add('select tsbm.sh,tsbm.sm,dzmc.jszh,dzmc.xm,tsjy.jcrq');
      sql.add('from tsbm,dzmc,tsjy');
      sql.Add('where (tsbm.sh=tsjy.sh)and (dzmc.jszh=tsjy.jszh)and(tsjy.jcbz=:jn)and(tsbm.sm like :name)');
      sql.Add('order by tsbm.sh');
      Parameters.ParamByName('jn').Value:=j;
      Parameters.ParamByName('name').Value:=gz;
      Prepared;
      Open;
      end
     else
      if g='借书证号' then
       with adoquery1 do
        begin
        Close;
        SQL.Clear;
        sql.Add('select tsbm.sh,tsbm.sm,dzmc.jszh,dzmc.xm,tsjy.jcrq');
        sql.add('from tsbm,dzmc,tsjy');
        sql.Add('where (tsbm.sh=tsjy.sh)and (dzmc.jszh=tsjy.jszh)and(tsjy.jcbz=:jn)and(tsjy.jszh like :name)');
        sql.Add('order by tsbm.sh');
        Parameters.ParamByName('jn').Value:=j;
        Parameters.ParamByName('name').Value:=gz;
        Prepared;
        Open;
        end
      else
        if g='读者姓名' then
         with adoquery1 do
          begin
           Close;
           SQL.Clear;
           sql.Add('select tsbm.sh,tsbm.sm,dzmc.jszh,dzmc.xm,tsjy.jcrq');
           sql.add('from tsbm,dzmc,tsjy');
           sql.Add('where (tsbm.sh=tsjy.sh)and (dzmc.jszh=tsjy.jszh)and(tsjy.jcbz=:jn)and(dzmc.xm like :name)');
           sql.Add('order by tsbm.sh');
           Parameters.ParamByName('jn').Value:=j;
           Parameters.ParamByName('name').Value:=gz;
           Prepared;
           Open;
          end
    end;
end;
end.