CREATE TABLE.......AS SELECT..........
举例:
1.创建副本并包含所有数据
create table emp_copy as select * from scott.emp;
2.创建副本并不包含数据
create table emp_copy as select * from scott.emp where 1=2;
3.创建不完全不相同的类型
create table emp_copy as select empno,ename,to_char(hiredate,'yyyy-mm-dd')ashiredate from scott.emp;