Sql server SQL Server:用于XML路径-嵌套/分组
我有如下数据:Sql server SQL Server:用于XML路径-嵌套/分组,sql-server,for-xml-path,Sql Server,For Xml Path,我有如下数据: 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
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中编写一个T-SQL查询,以返回如下数据:
<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>
但这给了我每行一个Order
节点(总共6个),而每行orderId
只有一个Order节点(总共2个)
有什么想法吗?请完成:这里有一个没有subselect的解决方案,对于大表来说应该执行得更快。相反,它对表进行分组的次数与XML中的级别相同,并使用分组ID标识级别(请参见和):
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')
谢谢你,伯特。“type”在子查询“for xml path”语句中起什么作用?@jared它的意思是“将此作为xml数据类型返回”。因此在上面的查询中,它只是将子查询作为一个小xml片段返回。
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')
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