How can I retrieve XML nodes dynamically from SQL Server and use XDocument to build a file from a template with them?

Question

I have an XML template with all the headers I need. I load it with XDocument , and then build the nodes using XElements . However, this means I am currently hard coding the data bits I need to go into my file.

I noticed with SQL Server I can use the XML datatype to store data in the database. Using this approach it would be better to look through each record and dynamically build the XML file.

However, I see some issues with my approach. There may be two nodes that share the same parent. Is there a way to store the nodes and their parent, and use something in XDocument to merge them?

Here is a sample chunk of my XML

<AddInfoCollection>
    <AddInfo>
        <Key>TransportReference</Key>
        <Value>666777888</Value>
    </AddInfo>              
    <AddInfo>
        <Key>UI_NKCarrierSCAC</Key>
        <Value>ABCD</Value>
    </AddInfo>              
    <AddInfo>
        <Key>SchDLoading</Key>
        <Value>1234</Value>
    </AddInfo>  
    <AddInfo>
        <Key>SchDArrival</Key>
        <Value>12345</Value>
    </AddInfo>                  
</AddInfoCollection>

In the database, I'd imagine the table would be:

• Field (varchar(200)
• Value (varchar(200)
• XML

Sample:

Field                 Value          XML
----------------------------------------------------------------
TransportReference    666777888      <AddInfoCollection>
                                       <AddInfo>
                                         <Key>TransportReference</Key>
                                         <Value>666777888</Value>
                                       </AddInfo>   
                                     <AddInfoCollection>

Answer 1

Use SELECT... FOR XML .

For example:

USE ADVENTUREWORKS
SELECT TOP 2 * FROM HUMANRESOURCES.EMPLOYEE FOR XML PATH

This returns the resultset as the following XML. Use other variants of SELECT...FOR XML to tailor the XML to your requirements.

<row>
  <EmployeeID>1</EmployeeID>
  <NationalIDNumber>14417807</NationalIDNumber>
  <ContactID>1209</ContactID>
  <LoginID>adventure-works\guy1</LoginID>
  <ManagerID>16</ManagerID>
  <Title>Production Technician - WC60</Title>
  <BirthDate>1972-05-15T00:00:00</BirthDate>
  <MaritalStatus>M</MaritalStatus>
  <Gender>M</Gender>
  <HireDate>1996-07-31T00:00:00</HireDate>
  <SalariedFlag>0</SalariedFlag>
  <VacationHours>21</VacationHours>
  <SickLeaveHours>30</SickLeaveHours>
  <CurrentFlag>1</CurrentFlag>
  <rowguid>AAE1D04A-C237-4974-B4D5-935247737718</rowguid>
  <ModifiedDate>2004-07-31T00:00:00</ModifiedDate>
</row>
<row>
  <EmployeeID>2</EmployeeID>
  <NationalIDNumber>253022876</NationalIDNumber>
  <ContactID>1030</ContactID>
  <LoginID>adventure-works\kevin0</LoginID>
  <ManagerID>6</ManagerID>
  <Title>Marketing Assistant</Title>
  <BirthDate>1977-06-03T00:00:00</BirthDate>
  <MaritalStatus>S</MaritalStatus>
  <Gender>M</Gender>
  <HireDate>1997-02-26T00:00:00</HireDate>
  <SalariedFlag>0</SalariedFlag>
  <VacationHours>42</VacationHours>
  <SickLeaveHours>41</SickLeaveHours>
  <CurrentFlag>1</CurrentFlag>
  <rowguid>1B480240-95C0-410F-A717-EB29943C8886</rowguid>
  <ModifiedDate>2004-07-31T00:00:00</ModifiedDate>
</row>