sql=@"select a.*,b.rm,b.stock from 表a as a
inner join
表b as b
on a.typename=b.typename
where a.typename='"+textbox2.Text+
"' and a.date>='"+textbox2.Text+"'";
select a.date, a.typename, a.dosage, b.rm, b.stock from a inner join b
on a.typename = b.typename
where a.date = 你输入的时间'' and a.typename = '你输入的typename'