oracle建表与数据插入

1.创建一个表并将表中数据复制到新表中

create table t as select * from dba_objects;

指定条件插入到新建表中 

create table tab_small  as select * from dba_objects where rownum<=10;

 2.创建表根据查询结果字段别名创建表

create table t2 as select rownum id ,dbms_random.string('b', 50) n ,data_object_id data_id from dba_objects where rownum<=10000;

 3.只复制表结构，不要数据

create table tab_small  as select * from dba_objects where 1=2;