Sqlserver With as

with t as (select * from emp where depno=10)

总结：可以看做将查询出来的语句块表示为一个临时表

select * from t where empno=xxx

union all sum(col1) as colsum from t

在这里就可以直接使用这个"临时表"

;WITH UpdateOrderInfo AS
(
SELECT o.Id FROM [Order] AS o WITH(NOLOCK)
INNER JOIN #TempOrder AS t ON o.Id = t.OrderId
LEFT JOIN OrderItem AS oi WITH(NOLOCK) ON oi.OrderId = o.Id
WHERE EXISTS(SELECT 1 FROM ShipmentItem WITH(NOLOCK) WHERE OrderItemId = oi.Id AND ShipmentItemShippingStatusId <>6)
)

总结下：其实就是把一大堆重复的代码放在这里，使用个别名，后面的代码访问这块的话直接用这个别名就可以了