SQL Server:用于XML路径 - 嵌套/分组
-
11-12-2019 - |
题
我有看起来的数据:
OrderID CustomerID ItemID ItemName
10000 1234 111111 Product A
10000 1234 222222 Product B
10000 1234 333333 Product C
20000 5678 111111 Product A
20000 5678 222222 Product B
20000 5678 333333 Product C
.
我想在SQL Server中编写T-SQL查询以返回这样的数据:
<Root>
<Order>
<OrderID>10000</OrderID>
<CustomerID>1234</CustomerID>
<LineItem>
<ItemID>11111</ItemId>
<ItemName>Product A</ItemName>
</LineItem>
<LineItem>
<ItemID>22222</ItemId>
<ItemName>Product B</ItemName>
</LineItem>
<LineItem>
<ItemID>33333</ItemId>
<ItemName>Product B</ItemName>
</LineItem>
</Order>
<Order>
<OrderID>20000</OrderID>
<CustomerID>5678</CustomerID>
<LineItem>
<ItemID>11111</ItemId>
<ItemName>Product A</ItemName>
</LineItem>
<LineItem>
<ItemID>22222</ItemId>
<ItemName>Product B</ItemName>
</LineItem>
<LineItem>
<ItemID>33333</ItemId>
<ItemName>Product B</ItemName>
</LineItem>
</Order>
</Root>
.
我尝试使用:返回XML中的查询
FOR XML PATH ('Order'), root ('Root')
.
但是,为我提供每行的生成acodeGode节点(总共6个)与每个世代odicetagcode的订单节点(总共2个)。
任何想法?
解决方案
select
OrderID,
CustomerID,
(
select
ItemID,
ItemName
from @Orders rsLineItem
where rsLineItem.OrderID = rsOrders.OrderID
for xml path('LineItem'), type
)
from (select distinct OrderID, CustomerID from @Orders) rsOrders
FOR XML PATH ('Order'), root ('Root')
. 其他提示
完成:以下是一个没有子选择的解决方案,应该为大表执行更快。相反,它在XML中有多次将该表组分组,并将级别标识使用组(请参阅 https://technet.microsoft.com/en-us/library/bb522495(v= sql.105).aspx 和 https://docs.microsoft.com/zh-US / SQL /关系 - 数据库/ XML /使用 - 显式模式 - for-XML ):
with rsOrders as (
select '10000' OrderID, '1234' CustomerID, '111111' ItemID, 'Product A' ItemName union
select '10000' orderId, '1234' customerID, '222222' itemID, 'Product B' ItemName union
select '10000' orderId, '1234' customerID, '333333' itemID, 'Product C' ItemName union
select '20000' orderId, '5678' customerID, '111111' itemID, 'Product A' ItemName union
select '20000' orderId, '5678' customerID, '222222' itemID, 'Product B' ItemName union
select '20000' orderId, '5678' customerID, '333333' itemID, 'Product C' ItemName
)
select case
when GROUPING_ID(ItemID) = 0 then 3
when GROUPING_ID(OrderID) = 0 then 2
else 1
end as tag,
case
when GROUPING_ID(ItemID) = 0 then 2
when GROUPING_ID(OrderID) = 0 then 1
else null
end as parent,
null as 'Root!1',
OrderID as 'Order!2!OrderID!element',
CustomerID as 'Order!2!CustomerID!element',
ItemID as 'LineItem!3!ItemID!element',
ItemName as 'LineItem!3!ItemName!element'
from rsOrders
group by grouping sets ((), (OrderID, CustomerID), (OrderID, CustomerID, ItemID, ItemName))
order by OrderID, CustomerID, ItemID, ItemName
for xml explicit, type
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