視圖1： 基於 hr.tt union all scott.tt ---》 scott.ttt
視圖2： 基於 視圖1-》scott.ttt 創建 system.tt
問題再現：
SQL> create table hr.tt (a number);
Table created.
SQL> create table lixora.tt (a number);
Table created.
SQL> create view scott.tt as select * from hr.tt union all select * from lixora.tt;
View created.
SQL> create view system.tt as select * from scott.tt;
View created.
SQL> select * from system.tt
A
----------
1
更新視圖2：
SQL> update system.tt set a=2;
update system.tt set a=2
*
ERROR at line 1:
ORA-01733: virtual column not allowed here
更新視圖1：
SQL> update scott.tt set A=2;
update scott.tt set A=2
*
ERROR at line 1:
ORA-01732: data manipulation operation not legal on this view
SQL> !oerr ora 1732
| ORA-01733: virtual column not allowed here Cause: An attempt was made to use an INSERT, UPDATE, or DELETE statement on an expression in a view. Action: INSERT, UPDATE, or DELETE data in the base tables, instead of the view. |
總結：
無法對包括表達式的view 進行dml 操作