SQL> select * from dual;D - XSQL> desc dual; 名称 是否为空?类型 ------------------------------- -------- ---- DUMMY VARCHAR2(1SQL> select rowid,dummy from dual;ROWID D ------------------ - 00000347.0000.0001 XSQL> insert into dual values('a');已创建 1 行。SQL> select * from dual;D - X aSQL>
continue:... SQL> select rowid,dummy from dual;ROWID D ------------------ - 00000347.0000.0001 X 00000347.0001.0001 aSQL>
ROWID是虚拟字段,你插入数据不会影响ROWID.
rowid is not a actual column but a pseudocolumn. You can also create tables and clusters that contain actual columns having the ROWID datatype.But,these cloumn maybe contain invalid rowid. if you want to get more detail,please read sql reference and Supplied PL-SQL Packages Reference(dbms_rowid).
rownum是Interger,也是系统生成.
如何写一个insert语句,
我是一个大菜鸟
不过我是在Procedure里面做的
-
XSQL> desc dual;
名称 是否为空?类型
------------------------------- -------- ----
DUMMY VARCHAR2(1SQL> select rowid,dummy from dual;ROWID D
------------------ -
00000347.0000.0001 XSQL> insert into dual values('a');已创建 1 行。SQL> select * from dual;D
-
X
aSQL>
SQL> select rowid,dummy from dual;ROWID D
------------------ -
00000347.0000.0001 X
00000347.0001.0001 aSQL>
You can also create tables and clusters that contain actual columns having the ROWID datatype.But,these cloumn maybe contain invalid rowid.
if you want to get more detail,please read sql reference and Supplied PL-SQL Packages Reference(dbms_rowid).