CREATE TABLE 表名 AS SELECT 语句
Connected to Oracle Database 11g Enterprise Edition Release 11.2.0.1.0
Connected as scott
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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 BOSTONSQL> 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--------------------------------------------
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由上面的使用 CREATE TABLE 表名 AS SELECT 语句可以看出：
??? 1：只会复制表数据和表结构，不会有任何约束。
??? 2：当 where 条件不成立时，只复制表结构，没有任务数据。
