c++ dbms模拟

create table std(sno int pkey,sname char(9),sage int pkey); create table std2(sno int pkey,sname char(9),sage int pkey); create table sc(sno int pkey,cno int pkey); create table sc(sno1 int pkey,cno1 int pkey,csname char(9)); insert into std values(1,lBei,43) insert into std values(2,gYu,41) insert into std values(3,zhFei,42) insert into std3 values(1,lBei,43); insert into std3 values(2,zhYun,39); insert into std3 values(3,zhGeL,34); insert into std values(4,zhYun,39) insert into std values(5,zhGeL,34) insert into std values(6,cCao,33) insert into std values(7,dWei,56) insert into std values(8,zhLiao,23) insert into std values(9,lDian,67) insert into std values(10,zhLiao,12) insert into std values(11,sQuan,76) insert into sc values(1,3); insert into sc values(2,8); insert into sc values(5,9); insert into sc values(8,2) insert into sc values(9,1) insert into sc values(11,7) insert into userlist values(1,lBei,2,4) insert into userlist values(2,gYu,3,4) insert into userlist values(3,zhFei,2,4) insert into userlist values(4,zhYun,2,4) insert into userlist values(5,zhGeL,3,4) insert into userlist values(6,cCao,3,4) insert into userlist values(7,dWei,3,4) insert into userlist values(8,zhLiao,3,4) insert into userlist values(9,lDian,6,4) insert into userlist values(10,zhLiao,1,4) insert into userlist values(11,sQuan,7,4) select * from userlist; insert into userlist values(2,xiaox,2,123) insert into userlist values(3,cp,3,123) insert into userlist values(4,lgao,3,123) delete from userlist where name =cp; create table count (id int pkey,name char(9) ,money int ) insert into count values(1,lBei,100) insert into count values(2,gYu,900) insert into count values(3,zhFei,400) insert into count values(4,zhYun,200) insert into count values(5,zhGeL,100) insert into count values(6,cCao,9000) insert into count values(7,dWei,42) delete from count where name = dWei; insert into count values(6,qqqqqqqqqqqq,9000) 并发控制 run task A select * from count where name = lBei; update count set money=money + 200 where name = zhFei; end run task B update count set money=money - 400 where name = lBei; update count set money=money + 200 where name = zhFei; end 日志恢复 run task d select * from count where name = lBei; update count set money=money - 200 where name = zhFei; int //模拟日志还未写完 run task e update count set money=money + 400 where name = lBei; update count set money=money - 200 where name = zhFei; end //写完日志，可完全执行，