oracle中create table with as和insert into with as语句

oracle支持使用with as 子句来创建表
语法：
create table table_name as
with clause_name as
（select query ）
[, clause_name1 as
(select query ) ...]
select column1,...columnn from clause_name；

语法：
insert into table_name
with clause_name as
（select query ）
[, clause_name1 as
(select query ) ...]
select column1,...columnn from clause_name；

例子：
--create with 语句

CREATE TABLE w_test_20 AS WITH  data_info_19 AS   (SELECT          NVL(ename,'unknow employee') AS ename,          DECODE(deptno,10,'ACCOUNTING',20,'RESEARCH',30,'SALES',40,'OPERATIONS','no this department') AS dname,         NVL(job,'unkown job') AS job ,         substr(to_char(hiredate,'yyyy-mm-dd'),1,7) AS hiredate,         CASE WHEN sal <= 1000 THEN 'D'               WHEN sal > 1000 AND sal <= 2000 THEN 'C'              WHEN sal > 2000 AND sal <= 3000 THEN 'B'              WHEN sal > 3000  THEN 'A'              ELSE 'unkown grade'          END AS grade,         ROUND(sal,2) AS sal,         FLOOR(nvl(comm,0)) AS comm,         NVL(sal,0)+NVL(comm,0) AS total_sal     FROM emp WHERE deptno IN      (SELECT DISTINCT deptno FROM dept)) SELECT * FROM data_info_19;

CREATE TABLE w_test_18 AS WITH dept_info AS (SELECT deptno AS deptno_1,dname FROM dept),emp_info AS(SELECT empno AS empno_1,ename,job,deptno FROM emp),other_info AS(SELECT empno,hiredate,NVL(sal,0)+NVL(comm,0) AS total_sal FROM emp )SELECT * FROM dept_info d LEFT JOIN emp_info e ON d.deptno_1=e.deptno RIGHT JOIN other_info o ON e.empno_1=o.empno ;

INSERT INTO w_test_19WITH  data_info_19 AS   (SELECT          NVL(ename,'unknow employee') AS ename,          DECODE(deptno,10,'ACCOUNTING',20,'RESEARCH',30,'SALES',40,'OPERATIONS','no this department') AS dname,         NVL(job,'unkown job') AS job ,         substr(to_char(hiredate,'yyyy-mm-dd'),1,7) AS hiredate,         CASE WHEN sal <= 1000 THEN 'D'               WHEN sal > 1000 AND sal <= 2000 THEN 'C'              WHEN sal > 2000 AND sal <= 3000 THEN 'B'              WHEN sal > 3000  THEN 'A'              ELSE 'unkown grade'          END AS grade,         ROUND(sal,2) AS sal,         FLOOR(nvl(comm,0)) AS comm,         NVL(sal,0)+NVL(comm,0) AS total_sal     FROM emp WHERE deptno IN      (SELECT DISTINCT deptno FROM dept)) SELECT * FROM data_info_19;

INSERT INTO  w_test_18 WITH dept_info AS (SELECT deptno AS deptno_1,dname FROM dept),emp_info AS(SELECT empno AS empno_1,ename,job,deptno FROM emp),other_info AS(SELECT empno,hiredate,NVL(sal,0)+NVL(comm,0) AS total_sal FROM emp )SELECT * FROM dept_info d LEFT JOIN emp_info e ON d.deptno_1=e.deptno RIGHT JOIN other_info o ON e.empno_1=o.empno ;