如何使用SQL查詢編輯XML值？

Question

我有一個SQL Server數據庫的XML列UserDetails具有這樣的價值：

<fleet> 
    <Setting name="city"/> 
    <UserSettings name="details"> 
     <UserSettings name="A1"> 
      <setting type="1" name="email"/> 
      <setting value="user"/> 
     </UserSettings> 
     <UserSettings name="A2"> 
      <setting type="2" name="phone"/> 
      <setting value="technician"/> 
     </UserSettings> 
    </UserSettings>  
</fleet> 

我會從數據庫中讀取和

<UserSettings name="A2"> . 

有人能指出我添加新設置我應該做什麼？

Answer 1

您可以使用sql:variable()來引入您在外部創建的值。你也可以使用Xml.exist()發現已經沒有了之前該新條目個XML：

DECLARE @myTbl TABLE(Descr VARCHAR(100),TheXml XML);    
INSERT INTO @myTbl VALUES 
( 
'Setting "A3" doesn''t exist','<fleet> 
    <Setting name="city" /> 
    <UserSettings name="details"> 
     <UserSettings name="A1"> 
      <setting type="1" name="email" /> 
      <setting value="user" /> 
     </UserSettings> 
     <UserSettings name="A2"> 
      <setting type="2" name="phone" /> 
      <setting value="technician" /> 
     </UserSettings> 
    </UserSettings> 
</fleet>' 
) 
,( 
'Setting "A3" exists already','<fleet> 
    <Setting name="city" /> 
    <UserSettings name="details"> 
     <UserSettings name="A1"> 
      <setting type="1" name="email" /> 
      <setting value="user" /> 
     </UserSettings> 
     <UserSettings name="A2"> 
      <setting type="2" name="phone" /> 
      <setting value="technician" /> 
     </UserSettings> 
     <UserSettings name="A3"> 
      <setting type="3" name="A3 setting" /> 
      <setting value="this exists already" /> 
     </UserSettings> 
    </UserSettings> 
</fleet>' 
); 

DECLARE @NewSetting XML= 
     N'<UserSettings name="A3"> 
      <setting type="3" name="new A3" /> 
      <setting value="new data" /> 
     </UserSettings>'; 


UPDATE @myTbl 
SET TheXml.modify('    
insert sql:variable("@NewSetting") 
as last into (/fleet/UserSettings)[1]')   
WHERE TheXml.exist(N'/fleet/UserSettings[@name="details"]/UserSettings[@name="A3"]')=0; 

SELECT * FROM @myTbl  

Answer 2

SQL SERVER向modify XML數據提供方法，並提供一種語言來執行此操作（XML DML）。
您需要對insert xml dml語句使用modify方法。

下面是完整的例子：

的樣本數據：

DECLARE @myDoc xml;    
SET @myDoc = 
'<fleet> 
    <Setting name="city" /> 
    <UserSettings name="details"> 
     <UserSettings name="A1"> 
      <setting type="1" name="email" /> 
      <setting value="user" /> 
     </UserSettings> 
     <UserSettings name="A2"> 
      <setting type="2" name="phone" /> 
      <setting value="technician" /> 
     </UserSettings> 
    </UserSettings> 
</fleet>'; 

聲明：

SET @myDoc.modify('    
insert <setting value="NEW SETTINGS" /> 
as first into (/fleet/UserSettings/UserSettings[@name="A2"])[1] ') ;   
SELECT @myDoc;   

結果：

<fleet> 
    <Setting name="city" /> 
    <UserSettings name="details"> 
     <UserSettings name="A1"> 
      <setting type="1" name="email" /> 
      <setting value="user" /> 
     </UserSettings> 
     <UserSettings name="A2"> 
      <setting value="NEW SETTINGS" /> 
      <setting type="2" name="phone" /> 
      <setting value="technician" /> 
     </UserSettings> 
    </UserSettings> 
</fleet>