oracle利用现有表创建新表

春桃6569

　　CREATE TABLE <newtable> AS SELECT {* | column(s)} FROM <oldtable> [WHERE <condition>];
exp:
    SQL> CREATE TABLE yonghu_bak AS SELECT * FROM yonghul;
    SQL> CREATE TABLE yonghu_bak AS SELECT id, name,sex FROM yonghu;
    SQL> CREATE TABLE yonghu_bak AS SELECT * FROM yonghu WHERE 1=2;

当遇到一个部门有多个员工记录，需要去取出每个部门薪水最少的那笔时，就可以用到分析函数row_number()
select * from(
　　select manager_id,employee_id,first_name,salary,row_number()
        over(partition by manager_id order by salary) as currowid
       from hr.employees)
where currowid = 1
　　
　　
　　PS：
　　（1）建一个新表，架构、字段属性、约束条件、数据记录跟旧表完全一样：
　　Create Table print_his_0013 as Select * from print_his_0007
　　（2）建一个新表，架构跟旧表完全一样，但没有内容：
　　Create Table print_his_0013 as Select * from print_his_0007 where 1=2