oracle创建临时表 sql oracle with as区别和用法?
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时间:2021-03-13 15:58:54
作者:admin
oracle with as区别和用法?
With as 就是将一个子查询的结果作为一张临时表,下面接着写select语句可以通过别名直接使用
语法:
针对一个别名
with tmp as (select * from tb_name)
针对多个别名
with
tmp as (select * from tb_name),
tmp2 as (select * from tb_name2),
tmp3 as (select * from tb_name3),
…
例子:
--相当于建了个e临时表
with e as (select * from scott.emp e where e.empno=7499)
select * from e
--相当于建了e、d临时表
with
e as (select * from scott.emp),
d as (select * from scott.dept)
select * from e, d where e.deptno = d.deptno
oracle创建临时表 sql oracle数据库 with as 与临时表的区别
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