left join语句中条件不同位置对结果的影响

以下两种写法：

 

SELECT a.*,b.id  FROM [SH_StoreHouseBillDetail] a
LEFT JOIN [SH_StoreHouseBill] b ON a.[StoreHouseBillID] =b.[ID] AND b.[BuyBillID]<>0

SELECT a.*,b.id  FROM [SH_StoreHouseBillDetail] a
LEFT JOIN [SH_StoreHouseBill] b ON a.[StoreHouseBillID] =b.[ID]
where b.[BuyBillID]<>0

 

写在where中，会有可能使得结果集的数量比sh_storehousebilldetail的数量还小