sqlite下执行update语句无法像sql Server下实现join，例如：

update Product set Product.StockNumber =Product.StockNumber-BuyNumber 
from Product join OrderListDetail on (Product.ID =OrderListDetail.ProductID) 
     join OrderList on (OrderList.ID=OrderListDetail.OrderListID)
where OrderListID='55170b21-58d2-4e6f-8821-f0a56fed9b52'

解决办法：换用replace，改写如下

replace into Product 
(ID,Caption,Number,ProjectTypeCaption,BuyPrice,MeasureUnit,StockNumber)
select Product.ID,Product.Caption,Product.Number,Product.ProjectTypeCaption,Product.BuyPrice,StockNumber-BuyNumber 
from Product join OrderListDetail on (Product.ID =OrderListDetail.ProductID) 
     join OrderList on (OrderList.ID=OrderListDetail.OrderListID)
where OrderListID='55170b21-58d2-4e6f-8821-f0a56fed9b52'

注意：Product表里的每个列都会重新赋值