--创建表
create table emp01
as
select * from employees
where department_id in (70,80)--
--创建表
create table emp02
as
select * from employees
where department_id in (80,90)
--查询 --并集
select * from employees
where department_id in (70,80)
union all
se…
--子查询 查询last_name为chen的manager信息select employee_id,last_name
from employees
where employee_id(
select manager_id
from employees
where last_nameChen
)
运行结果 --查询
select employee_id,manager_id,department_id
from employees
where manager_id in(
…
DOM的基本讲解一、DOM(Document Object Model)文档对象模型1、有属性有方法1 var person {2 name:‘派大星‘,3 fav:function(){4 }5 }2、js中对象分类三种(1)用户定义对象(2)内建对象 Array Date Math (内置)(3)宿主对象3、Model Map(地图)(1)把 DOM 看做一颗“树”(2)DOM 把文…