求帮助

procedure TForm1.Button1Click(Sender: TObject);
var
i,j:integer;
data1,data2:string ;
begin
for j:=2013 to 2014 do
begin
for i:=10 to 11 do
begin
data1:=inttostr(j)+'-'+inttostr(i)+'-01' ;
data2:=inttostr(j)+'-'+inttostr(i+1)+'-01' ;
showmessage(data1) ;
with adoquery1 do
begin
close;
sql.Clear;
sql.add('select sum(jz) from ylrkb where rq >='''+data1+''' and rq<'''+data2+'''');
open;
end;
end
end
end;
查询结果用控件DBgrid显示 为什么只能显示一个数据