Question

我有这个SQL Server查询，它返回每个组的所有组成员。但我想确定每个组成员是否至少有一个“活动”设备。为此，我使用Row_Number并对groupID和memberID进行分区，并通过'Active'列进行排序，该列是BIT类型。以下查询的结果是正确的。但我只使用数据子集。我读过，因为有点列不是数字，你不应该按它排序。它会产生不可预测的结果。

如何将BIT列转换为INT并在ROW_NUMBER函数中使用它？

这是查询：

WITH OrderedGroupMembers AS
(
SELECT g.GroupID AS GroupID, gm.RecipientID AS MemberID, r.RecipientName AS MemberName, d.Active AS ActiveDevice,
    ROW_NUMBER() OVER(PARTITION BY g.GroupID, gm.RecipientID ORDER BY d.Active DESC) AS RowNumber
FROM PagingToolGroups g JOIN PagingToolGroupMembers gm ON g.GroupID = gm.GroupID
        JOIN PagingToolRecipients r ON r.RecipientID = gm.RecipientID
        JOIN PagingToolDevices d ON d.RecipientID = gm.RecipientID
WHERE g.GroupCreatorID = 'ge39se35'
)
SELECT GroupID, MemberID, MemberName, ActiveDevice
FROM OrderedGroupMembers
WHERE RowNumber = 1

感谢。

更新这是我的新查询，但我想知道是否有更有效的方法...

WITH OrderedGroupMembers AS
(
SELECT GroupID, MemberID, MemberName, ActiveDevice, 
    ROW_NUMBER() OVER(PARTITION BY GroupID, MemberID ORDER BY ActiveDevice DESC) AS RowNumber
FROM (
        SELECT g.GroupID AS GroupID, gm.RecipientID AS MemberID, r.RecipientName AS MemberName, CAST(d.Active AS INT) ActiveDevice  
        FROM PagingToolGroups g JOIN PagingToolGroupMembers gm ON g.GroupID = gm.GroupID
                JOIN PagingToolRecipients r ON r.RecipientID = gm.RecipientID
                JOIN PagingToolDevices d ON d.RecipientID = gm.RecipientID
        WHERE g.GroupCreatorID = 'ge35s39'
    ) AS ActiveAsNum
)
SELECT GroupID, MemberID, MemberName, ActiveDevice
FROM OrderedGroupMembers
WHERE RowNumber = 1

Answer 1

位类型没有问题。您可以按位类型排序任何其他类型。使用位的一个限制是您不能在一个上聚合，但在这种情况下您可以将其转换为任何数字类型。但事实并非如此，所以您只需按活动列排序即可。这是合法的，不应该有任何问题。

SQL Server查询在Row_Number Order By中使用位列

1 个答案: