在SQL Server

Question

Declare @MainXml XML = 
'<?xml version="1.0" encoding="utf-8"?> 
<result> 
<cash number="10"> 
<account amt="11.00" status="Closed"/> 
<account amt="12.00" status="Closed"/>      
</cash>   
<cash number="20"> 
<account amt="21.00" status="Closed"/> 
<account amt="22.00" status="Closed"/>      
</cash>   
</result>' 

讀取XML標籤重複我使用閱讀下面的查詢

Declare @Innerxml xml; 
SELECT @Innerxml = T.c.query('<result>{/result/cash}</result>') 
FROM @MainXml.nodes('result') T(c) 

SELECT 
Result.Claim.value('(./@number)[1]','varchar(max)') as C1, 
Result.Claim.value('(./@amt)[1]','varchar(max)') as C2, 
Result.Claim.value('(./@status)[1]','varchar(max)') as C3 
From @Innerxml.nodes('/result/cash/account') Result(Claim) 

我想讀在DB作爲下面的XML和存儲數據。

C1 C2  C3 
---------------- 
10 11.00 Closed 
10 12.00 Closed 
20 21.00 Closed 
20 22.00 Closed 

但我的查詢將返回只在C1列 NULL請幫我在這裏。在此先感謝

Answer 1

在SQL Server你不應該使用XML查詢父軸。創建的查詢計劃將爲O（n ）。對於XML中的每個節點，將檢查XML中的所有節點。

首先粉碎result/cash然後粉碎在account交叉申請。

select C.X.value('@number', 'varchar(max)') as C1, 
     A.X.value('@amt', 'varchar(max)') as C2, 
     A.X.value('@status', 'varchar(max)') as C3 
from @MainXml.nodes('result/cash') as C(X) 
    cross apply C.X.nodes('account') as A(X) 

_{我沒有看到創建第二個XML變量的點。直接使用@MainXML。}

Answer 2

@number是<cash>屬性，但您的上下文節點是<account>。在訪問屬性之前，需要上一層XML樹以訪問節點<cash>。你可以做..到達當前節點的父XPath中：

SELECT 
Result.Claim.value('(../@number)[1]','varchar(max)') as C1, 
Result.Claim.value('(./@amt)[1]','varchar(max)') as C2, 
Result.Claim.value('(./@status)[1]','varchar(max)') as C3 
From @Innerxml.nodes('/result/cash/account') Result(Claim)