sqlite3 e:\\test.db
create table t1(f1 TEXT,f2 TEXT,f3 integer);
create table t2(f1 TEXT,f2 TEXT);
insert into t1 values("x1","y1",9);
insert into t1 values("x1","y1",8);
insert into t1 values("x1","y1",3);
insert into t1 values("x1","y2",9);
insert into t1 values("x1","y3",9);
insert into t1 values("x1","y4",9);
insert into t1 values("x1","y2",7);
insert into t2 values("x1","y1");
insert into t2 values("x1","y2");
1.为何使用
select t1.* from t1,t2 where not(t1.f1=t2.f1 and t1.f2=t2.f2) ;
不能得到结果
"x1","y3",9
"x1","y4",9
2.如何使用delete from 得到结果？
delect from t1(select t1.* from t1,t2 where t1.f1 =t2.f1 and t1.f2=t2.f2) ; 这句话如何修改，才能得到上面的结果？
------解决思路----------------------
楼主的逻辑好乱.想一下,t1表有7条记录,t2表有2条记录,组合起来共有14条记录,一条一条用楼主的条件检测一下吧.
要实现此要求请查一下 exists 的用法吧