学习Microsoft SQL Server 2008技术内幕：T-SQL语法基础--第4章

use TSQLFundamentals2008
select * 
from Sales.Customers as C
where c.country=N‘Spain‘

select * 
from Sales.Customers as C
where c.country=N‘Spain‘ and exists(select * from Sales.Orders as O where o.custid=C.custid)

select * 
from Sales.Customers as C
where c.country=N‘Spain‘ and not exists(select * from Sales.Orders as O where o.custid=C.custid)

select OBJECT_ID(‘Sales.OrderTotalsByYear‘)
if OBJECT_ID(‘Sales.OrderTotalsByYear‘) is not null  drop view Sales.OrderTotalsByYear

go
create view Sales.OrderTotalsByYear with schemabinding 
as 
  select 
    YEAR(o.orderdate) as orderyear,
    SUM(od.qty) as qty  
  from 
  Sales.Orders as o
    join Sales.OrderDetails as od on o.orderid=od.orderid
  group by YEAR(o.orderdate)
go