请大家不要上机实验, 凭你的经验和推断, 给出本小题目的答案. 如果做了试验再来回答就没啥意思了
create table t(id number not null);
insert into t values(1);
insert into t values(2);
insert into t values(3);
commit;
现在连续两次执行同一个SQL语句,如下:
SQL>select * from t where rownum <= 1 for update skip locked;
ID
----------
1
1 row selected.
SQL>select * from t where rownum <= 1 for update skip locked;
请问: 这里应该显示什么结果?
A. | B. | C. | D. | no rows selected
| ID
----------
1
1 row selected. | ID
----------
2
1 row selected. | ID
----------
3
1 row selected. |
现在再开启另一个 SESSION窗口执行:
SQL>select * from t where rownum <= 1 for update skip locked;
那么再次请问: 这里又应该显示什么结果?
选项和前面相同. |