選課系統(tǒng)，當(dāng)同意學(xué)號(hào)選課數(shù)量超過(guò)則回滾事務(wù)，符合條件則正常插入數(shù)據(jù)

--開(kāi)始一個(gè)事務(wù)處理Begin Tran T1 --執(zhí)行插入操作insert into Courselist values('20100021','01');insert into Courselist values('20100021','02');insert into Courselist values('20100021','03');insert into Courselist values('20100021','04');insert into Courselist values('20100021','05');--判斷同一學(xué)號(hào)的選課數(shù)量是否符合IF(select COUNT(StudentID) as cnt from Courselist where StudentID='20100021')>4BEGIN--不符合，回滾事務(wù) rollback Tran T1ENDELSEBEGIN--符合，提交事務(wù) commit Tran T1END