PG中，执行如下语句，实际插入的值为：C BEGIN; INSERT INTO table1 VALUES (1); SAVEPOINT my_savepoint; INSERT INTO table1 VALUES (2); ROLLBACK TO SAVEPOINT my_savepoint; INSERT INTO table1 VALUES (3); COMMIT; A 1,3,2 B 1,2,3 C 1,3 D 1,2