我用C#写了个查询ACCESS数据表条件并且显示在DataGridView上，如：
string strsql;
            string conditon = "";
            DataAccess data = new DataAccess();
            DataSet ds;
            if (txtbanbie.Text != "")
            {
                conditon += "and Class='" + txtbanbie.Text + "'";
            }
            strsql = "select distinct Studentinfo.Class as 班别,Studentinfo.Sid as 学号,Studentinfo.Sname as 姓名,Classinfo.Sum as 总分,Classinfo.Avg as 平均分 from Studentinfo,Classinfo" + conditon;
            data.dataCon();
            ds = data.getDataSet(strsql);
            dgv2.DataSource = ds.Tables[0];
代码应该没错吧，可是输入条件后点击查询直接无反应地退出了测试，好像是数据库哪里出错了，请问有那位知道是什么原因吗？