开始与结束时间的判定

sql += " ((Item_jieshu>='" + enddate + "'";
sql += " and Item_kaishi<='" + startdate + "'";
sql += ") or (Item_jieshu<'" + enddate + "'";
sql += " and Item_jieshu>'" + startdate + "'";
sql += ") or (Item_jieshu<'" + enddate + "'";
sql += " and Item_kaishi>'" + startdate + "'";
sql += ") or (Item_kaishi<'" + enddate + "'";
sql += " and Item_kaishi>'" + startdate + "')) ";