CREATE TABLE 表名 AS SELECT 語句

 

SQL> select * from dept;
 
DEPTNO DNAME          LOC
------ -------------- -------------
    10 ACCOUNTING     NEW YORK
    20 RESEARCH       DALLAS
    30 SALES          CHICAGO
    40 OPERATIONS     BOSTON
 
SQL> create table dept2 as select * from dept;
 
Table created
 
SQL> select * from dept;
 
DEPTNO DNAME          LOC
------ -------------- -------------
    10 ACCOUNTING     NEW YORK
    20 RESEARCH       DALLAS
    30 SALES          CHICAGO
    40 OPERATIONS     BOSTON
 
SQL> select * from dept2;
 
DEPTNO DNAME          LOC
------ -------------- -------------
    10 ACCOUNTING     NEW YORK
    20 RESEARCH       DALLAS
    30 SALES          CHICAGO
    40 OPERATIONS     BOSTON

SQL> create table dept3 as select * from dept where 1 = 2;
 
Table created
 
SQL> select * from dept3;
 
DEPTNO DNAME          LOC
------ -------------- -------------
 
SQL> select OWNER from user_constraints where table_name = 'DEPT';
 
OWNER
--------------------------------------------------------------------------------
SCOTT
 
SQL> select OWNER from user_constraints where table_name = 'DEPT2';
 
OWNER
--------------------------------------------------------------------------------
 

Connected to Oracle Database 11g Enterprise Edition Release 11.2.0.1.0
Connected as scott

由上面的使用 CREATE TABLE 表名 AS SELECT 語句可以看出：

    1：只會復制表數據和表結構，不會有任何約束。

    2：當 where 條件不成立時，只復制表結構，沒有任務數據。

轉自：http://ears.iteye.com/blog/1470605