如何计算货件的总行数答案

【问题标题】：How to Count total rows on a shipment如何计算货件的总行数
【发布时间】：2018-10-12 12:10:21
【问题描述】：

我正在尝试计算每批货物的总行数：

SELECT  Shipments.ShipmentId, 
        SalesOrders.SalesOrderId as OrderNumber,  
        Count(SalesOrderItems.SalesOrderItem) as NumberOfLines

FROM SalesOrders 

INNER JOIN SalesOrderItems on SalesOrders.SalesOrder = SalesOrderItems.SalesOrder 
INNER JOIN Shipments on SalesOrderItems.SalesOrder = Shipments.SalesOrder

GROUP BY SalesOrderItems.SalesOrderItem, SalesOrders.SalesOrderId, Shipments.ShipmentId

ORDER BY Shipments.ShipmentID ASC

目前我得到：

ShipmentID  | OrderNumber    | NumberOfLines
SH00000001  | SO-0000001     | 1
SH00000001  | SO-0000001     | 1
SH00000002  | SO-0000007     | 1
SH00000003  | SO-0000006     | 1
SH00000003  | SO-0000006     | 1

我应该得到：

ShipmentID  | OrderNumber    | NumberOfLines
SH00000001  | SO-0000001     | 1
SH00000001  | SO-0000001     | 2
SH00000002  | SO-0000007     | 1
SH00000003  | SO-0000006     | 1
SH00000003  | SO-0000006     | 2

【问题讨论】：

标签： sql join count

【解决方案1】：

从您的 group by 子句中删除 SalesOrderItems.SalesOrderItem，您不需要它（可以从它推断出它在您的示例结果数据集上不存在）。

【讨论】：

【解决方案2】：

您的GROUP BY 子句应与SELECT 中的未聚合 列匹配：

SELECT s.ShipmentId, 
       so.SalesOrderId as OrderNumber,  
       Count(soi.SalesOrderItem) as NumberOfLines
FROM SalesOrders so INNER JOIN
     SalesOrderItems soi
     ON so.SalesOrder = soi.SalesOrder INNER JOIN
     Shipments s
     ON soi.SalesOrder = s.SalesOrder
GROUP BY soi.SalesOrderId, s.ShipmentId
ORDER BY s.ShipmentID ASC;

请注意，我添加了表别名。这些使查询更易于编写和阅读。

【讨论】：