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_salFROM 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_salFROM 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 ;
