1 不能和for update一起用

2 select子句不能包含sequence，如currval，nextval这些

3 如果用在物化视图里，物化视图不能增量刷新

drop table t purge; create table t (id int, name varchar2(20)); insert into t select level, 'name'||level from dual connect by level < 100; commit;

返回前n行

SQL> select * from t where id between 30 and 70 order by id   fetch next 3 rows only;         ID NAME ---------- --------------------------------------------------         30 name30         31 name31         32 name32 分页 SQL> select * from t where id between 30 and 70 order by id   offset 30 rows fetch next 3 rows only;         ID NAME ---------- --------------------------------------------------         60 name60         61 name61         62 name62 返回百分之n行 SQL> select * from t where id between 30 and 70 order by id   fetch first 25 percent rows only;         ID NAME ---------- --------------------------------------------------         30 name30         31 name31         32 name32         33 name33         34 name34         35 name35         36 name36         37 name37         38 name38         39 name39         40 name40 11 rows selected.

返回并列前n行

插入重复数据

commit;

普通智能严格返回前2行

SQL> select * from t order by id fetch next 2 rows   only;         ID NAME ---------- --------------------------------------------------          1 name1          2 name2 

使用with ties 后，就能把“并列第二”的全都显示出来 SQL> select * from t order by id fetch next 2 rows   with ties;         ID NAME ---------- --------------------------------------------------          1 name1          2 name2          2 name2          2 name2          2 name2          2 name2          2 name2          2 name2          2 name2 9 rows selected.