------------------原文： http://blog.csdn.net/u012157032/article/details/73658155
下面的ew在实际项目中我因为框架的原因我用了o,
所以按具体情况而定， 如果查询昨天的数据的话就减一，如：
$sql .= " AND date(o.date_added) = curdate()-1";
--------------查"当天"的数据-----------------
SELECT ew.orderid, ew.carid, ew.userid, ew.`status`, ew.reservetime, ew.starttime, ew.endtime, ew.canceltime, eu.nickname, ec.plateid FROM evlib_workorder ew LEFT JOIN evlib_user eu ON eu.userid = ew.userid LEFT JOIN evlib_car ec ON ec.carid = ew.carid WHERE date(ew.reservetime) = curdate() ORDER BY ew.reservetime DESC;
--------------查"上周"的数据-----------------
SELECT ew.orderid, ew.carid, ew.userid, ew.`status`, ew.reservetime, ew.starttime, ew.endtime, ew.canceltime, eu.nickname, ec.plateid FROM evlib_workorder ew LEFT JOIN evlib_user eu ON eu.userid = ew.userid LEFT JOIN evlib_car ec ON ec.carid = ew.carid WHERE YEARWEEK(date_format(ew.reservetime, '%Y-%m-%d')) = YEARWEEK(now()) - 1 ORDER BY ew.reservetime DESC;
--------------查"本周"的数据-----------------
SELECT ew.orderid, ew.carid, ew.userid, ew.`status`, ew.reservetime, ew.starttime, ew.endtime, ew.canceltime, eu.nickname, ec.plateid FROM evlib_workorder ew LEFT JOIN evlib_user eu ON eu.userid = ew.userid LEFT JOIN evlib_car ec ON ec.carid = ew.carid WHERE YEARWEEK(date_format(ew.reservetime, '%Y-%m-%d')) = YEARWEEK(now()) ORDER BY ew.reservetime DESC;
--------------查"本月""当前月"的数据-----------------
SELECT ew.orderid, ew.carid, ew.userid, ew.`status`, ew.reservetime, ew.starttime, ew.endtime, ew.canceltime, eu.nickname, ec.plateid FROM evlib_workorder ew LEFT JOIN evlib_user eu ON eu.userid = ew.userid LEFT JOIN evlib_car ec ON ec.carid = ew.carid WHERE date_format(ew.reservetime,'%Y-%m')=date_format(now(),'%Y-%m') ORDER BY ew.reservetime DESC;
--------------查"上个月"的数据-----------------
SELECT ew.orderid, ew.carid, ew.userid, ew.`status`, ew.reservetime, ew.starttime, ew.endtime, ew.canceltime, eu.nickname, ec.plateid FROM evlib_workorder ew LEFT JOIN evlib_user eu ON eu.userid = ew.userid LEFT JOIN evlib_car ec ON ec.carid = ew.carid WHERE date_format(ew.reservetime,'%Y-%m')=date_format(DATE_SUB(curdate(), INTERVAL 1 MONTH),'%Y-%m') ORDER BY ew.reservetime DESC;
--------------查"距离当前现在6个月"的数据-----------------
SELECT ew.orderid, ew.carid, ew.userid, ew.`status`, ew.reservetime, ew.starttime, ew.endtime, ew.canceltime, eu.nickname, ec.plateid FROM evlib_workorder ew LEFT JOIN evlib_user eu ON eu.userid = ew.userid LEFT JOIN evlib_car ec ON ec.carid = ew.carid WHERE ew.reservetime between date_sub(now(),interval 6 month) and now() ORDER BY ew.reservetime DESC;