Parse non-standard SQL server XML column with c#

Question

I'm trying to parse a xml column in Sql server the code kinda works but when the code iterates through the xmlnodelist it will write the first node multiple times depending on how many nodes there are which would be 2 based on this xml example. When I put a watch on the XmlNodeList there is the right amount of results in the array and all have the correct results.

Is this the correct way to do this or is there another way? and why is this just getting the first node and rewriting it multiple times?

I have this xml column stored in SQL Server and it will insert 2 of the same first node, sorry for all the code and the xml mess. This is the way the program stores it.

    <Compatibilities>
    <Compatibility>
    <NameValue>
      <Name>Make</Name>
      <Value>Pontiac</Value>
    </NameValue>
    <NameValue>
      <Name>Model</Name>
      <Value>Grand Am</Value>
    </NameValue>
    <NameValue>
      <Name>Year</Name>
      <Value>1999</Value>
    </NameValue>
    <NameValue>
      <Name>Trim</Name>
      <Value>All</Value>
    </NameValue>
    <NameValue>
      <Name>Engine</Name>
      <Value>All</Value>
    </NameValue>
    <Notes>Rear Left</Notes>
    </Compatibility>
    <Compatibility>
    <NameValue>
      <Name>Make</Name>
      <Value>Pontiac</Value>
    </NameValue>
    <NameValue>
      <Name>Model</Name>
      <Value>Grand Am</Value>
    </NameValue>
    <NameValue>
      <Name>Year</Name>
      <Value>2005</Value>
    </NameValue>
    <NameValue>
      <Name>Trim</Name>
      <Value>All</Value>
    </NameValue>
    <NameValue>
      <Name>Engine</Name>
      <Value>All</Value>
    </NameValue>
    <Notes>Rear Left</Notes>
  </Compatibility>
  </Compatibilities>

and my c# code..while loop on a SqlDataReader

while (itemDataReader.Read())
{
    var xmldoc = new XmlDocument();
    string sku = itemDataReader[0].ToString();

    xmldoc.LoadXml(itemDataReader[1].ToString());
    XmlNodeList xnList = xmldoc.SelectNodes("/Compatibilities/Compatibility");

    foreach (XmlNode x in xnList)
    {
        itemList.Add(new Item
        {
            itemSku = sku,
            year = x.SelectSingleNode("//NameValue[Name='Year']/Value").InnerText,
            make = x.SelectSingleNode("//NameValue[Name='Make']/Value").InnerText,
             model = x.SelectSingleNode("//NameValue[Name='Model']/Value").InnerText,
             trim = x.SelectSingleNode("//NameValue[Name='Trim']/Value").InnerText,
            engine = x.SelectSingleNode("//NameValue[Name='Engine']/Value").InnerText,
            notes = x.SelectSingleNode("//Notes").InnerText,
        });
    }
}

Uhm, // parses all nodes in the document. If you only want to search for nodes under xnList, you should use .// instead. — Patrick
– Patrick, Commented Dec 10, 2014 at 20:44

Patrick · Accepted Answer · 2014-12-10 21:13:17Z

According to msdn; SelectSingleNode returns (emphasis by me)

The first XmlNode that matches the XPath query or null if no matching node is found.

The XPath "//NameValue[Name='Year']/Value" searches for all nodes in the document and not relative to the current node, so the first node in your document will be fetched each time. If you prefix the XPath with a dot you should only receive the nodes under the current XNode.

itemList.Add(new Item
{
    itemSku = sku,
    year = x.SelectSingleNode(".//NameValue[Name='Year']/Value").InnerText,
    make = x.SelectSingleNode(".//NameValue[Name='Make']/Value").InnerText,
    model = x.SelectSingleNode(".//NameValue[Name='Model']/Value").InnerText,
    trim = x.SelectSingleNode(".//NameValue[Name='Trim']/Value").InnerText,
    engine = x.SelectSingleNode(".//NameValue[Name='Engine']/Value").InnerText,
    notes = x.SelectSingleNode(".//Notes").InnerText,
});

You can find more examples for XPath queries on msdn, XPath Examples.

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