php拾遗

    //计算库存
    foreach($aGoodsLst as $goodsid => $aGoods)
    {
        $aGoods['price'] = $aGoods['buy']==0?0:($aGoods['buymoney']/ $aGoods['buy']);
        $aGoods['stock'] = $aGoods['buy'] - $aGoods['sell'] + $aGoods['return'];  
        $aGoods['stockmoney'] = $aGoods['stock'] * $aGoods['price']; //库存金额以进价为准 
        
        //重新计算销售金额 
        $aGoods['sell'] = $aGoods['sell'] - $aGoods['return'];  
        $aGoods['sellmoney'] = $aGoods['sellmoney'] - $aGoods['returnmoney'];  
        
        //盈余
        $aGoods['earn'] = $aGoods['sellmoney']-$aGoods['buymoney']; 
        
        extract($aGoods);
        
        $sSql = "UPDATE goods SET buy='$buy',buymoney='$buymoney',stock='$stock',stockmoney='$stockmoney',sell='$sell',sellmoney='$sellmoney',`return`='$return',returnmoney='$returnmoney',earn='$earn' WHERE id=$goodsid";
        $oDb->query($sSql); 
    }

在for循环中的extract时，如果数组的下标不包含到$buy等后续要使用的变量，会导致使用其他不相关的或者前一次生成的变量，需要特别的注意