数据库中图片显示报错 ----'JPEG error #42

代码入下:
var
jpegimage:tjpegimage;
jpegimage1:tjpegimage;

begin
With ADOQuery2 do
begin //3
Close;
SQL.Clear;
SQL.Add('select * from Mon_Transaction ');
SQL.Add('where Trans_Card_No=:pNo');
//Parameters.ParamByName('pTime').Value:=StrToDateTime('2004-9-21 18:35:14');
Parameters.ParamByName('pNo').Value:='11111111113';
Open;
if RecordCount <>0 then
begin
///////////////////// 显示照片 /////////////////////
MasterPicture.Picture.Graphic :=nil;
CarPicture.Picture.Graphic :=nil;
jpegimage := tjpegimage.Create ; //通过jpegimage将图像显示在image1,否则会出错
jpegimage1 := tjpegimage.Create ; //通过jpegimage将图像显示在image1,否则会出错
try
jpegimage.Assign(fieldbyname('Trans_Photo_1'));
jpegimage1.Assign(fieldbyname('Trans_Photo_2'));
MasterPicture.Picture.Graphic :=jpegimage;
CarPicture.Picture.Graphic :=jpegimage1;
finally
jpegimage.Free ;
jpegimage1.Free ;
end; //end try
//////////// 显示照片 结束 ////////////////////
end //end if
else
ShowMessage('没记录');
end; //3 end with
end;
问题:
1. 我执行时会出现 JPEG error #42 提示
2.数据库中我有一datetime字段 'Trans_Datetime' 我用如下语句时查不到记录
SQL.Add('select * from Mon_Transaction ');
SQL.Add('where Trans_Card_No=:pNo and Trans_Datetime=:pTime');
Parameters.ParamByName('pTime').Value:=StrToDateTime('2004-9-21 18:35:14');
Parameters.ParamByName('pNo').Value:='11111111113';
Open

事实上这条记录确实存在.
初学delphi,请各位大虾给指点.