多表连接如何设主表，就是取主表的全部记录为基础。 内有语句
SELECT benefaction.ID, benefaction.RDno, donation.DName, pupil.SName, benefaction.RAmount, benefaction.ROdate, benefaction.State
FROM (benefaction INNER JOIN donation ON benefaction.RDID = donation.ID) INNER JOIN pupil ON benefaction.RSid = pupil.ID
想取benefaction的全部记录，现在只取了一部分..
[解决办法]
SELECT benefaction.ID, benefaction.RDno, donation.DName, pupil.SName, benefaction.RAmount, benefaction.ROdate, benefaction.State
FROM benefaction
left join donation ON benefaction.RDID = donation.ID
left join pupil ON benefaction.RSid = pupil.ID
