求教：GridView更新问题

//更新
    protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        sqlcon = new SqlConnection(strCon);
        string sqlstr = "update lc_yr set yjh='"
            + ((CheckBox)(GridView1.Rows[e.RowIndex].Cells[0].Controls[0])).Text.ToString().Trim() + "',yd='"
            + ((TextBox)(GridView1.Rows[e.RowIndex].Cells[1].Controls[0])).Text.ToString().Trim() + "',yddclh='"
            + ((TextBox)(GridView1.Rows[e.RowIndex].Cells[2].Controls[0])).Text.ToString().Trim() + "',ydyy='"
            + ((TextBox)(GridView1.Rows[e.RowIndex].Cells[3].Controls[0])).Text.ToString().Trim() + "' where id='"
            + GridView1.DataKeys[e.RowIndex].Value.ToString() + "'";
        sqlcom = new SqlCommand(sqlstr, sqlcon);
        sqlcon.Open();
        sqlcom.ExecuteNonQuery();
        sqlcon.Close();
        GridView1.EditIndex = -1;
        bind();
    }

运行出现：yd数据修改（yd是CheckBox），yddclh数据消失，ydyy修改了yddclh的数据，yjh修改了ydyy，yjh数据消失。高手帮忙分析分析问题出在那里。谢谢了。