=跟*=有什么不同?
有一SQL语句:
Select a.fID,a.fCode,a.fName,a.fColor,a.fSpec,a.fLevel,b.fQty,c.fQty
from tProduct a,tPurchasePlanning b,vPOUnSubmitQty c
where a.fID = b.fResID
and a.fID *= c.fResID
执行后,有数据显示,但把最后一项中的 "*= "改为 "= "却没有数据显示,不知 "*= "的含义是什么?
望指点.
谢谢!
[解决办法]
改為
Select a.fID,a.fCode,a.fName,a.fColor,a.fSpec,a.fLevel,b.fQty,c.fQty
from tProduct a Inner Join tPurchasePlanning b On a.fID = b.fResID
Left Join vPOUnSubmitQty c On a.fID = c.fResID
