从XML文件检索值

Question

I have Multiple XML Files that look like below

<?xml version="1.0" encoding="UTF-8"?>
<schema>
<sp_transaction_id name="sp_transaction_id" value="1" />
<sp_year name="sp_year" value="2015" />
<sp_first_name name="sp_first_name" value="James" />
<sp_gender name="sp_gender" value="Male" />
<sp_date_of_birth name="sp_date_of_birth" value="06-06-1999" />
</schema>

The XML Format i think is in Key-Value Pairs. I want to extract these values and store it into a database(SQL Server 2012) table, with the name(eg; sp_year) as Column Name and value(eg; 2015) as the Column value using ASP.NET C#. I think i can upload the file and read it like this :

string fileName = Path.GetFileName(FileUpload1.PostedFile.FileName);
string filePath = Server.MapPath("~/Uploads/") + fileName;
FileUpload1.SaveAs(filePath);
string xml = File.ReadAllText(filePath);

But thats pretty much it ( Sorry Im a beginner ). Please Guide me. Thanks

Answer 1

For reading data from an xml file you don't need to upload it.You can give path of xml and read from it.You can use following method to read from xml

public static XmlDocument LoadXmlDocument(string xmlPath)
    {
        if ((xmlPath == "") || (xmlPath == null) || (!File.Exists(xmlPath)))
            return null;

        StreamReader strreader = new StreamReader(xmlPath);
        string xmlInnerText = strreader.ReadToEnd();
        strreader.Close();

        XmlDocument xmlDoc = new XmlDocument();
        xmlDoc.LoadXml(xmlInnerText);

        return xmlDoc;
    }

For reading data from xml you can use

XmlDocument xmlDoc = LoadXmlDocument(xmlPath);

XmlNodeList nodes = xmlDoc .SelectNodes("//*");

                foreach (XmlElement node in nodes)
                {
                  .
                  .
                  .
                }

In foreach loop you can get your required values eg sp_year

Answer 2

The answer below shows how to create an XmlDocument from it. I would suggest to use it as a User-Defined class if you know whether Xml schema change. First of all you should create POCO class appropriate to Xml file schema using XmlAnnotations. Secondly: Having path of the file:

XmlSerializer serializer = new XmlSerializer(typeof(definedclass));
using (FileStream fs = File.Open(pathtofile))
using (XmlReader reader = XmlReader.Create(fs))
{
    var xmlObject = serializer.Deserialize(reader); 
}

xmlObject is now your user-defined class with values from xml. Regards, Rafal

Answer 3

You can use the following code to get the key value pairs

XDocument doc = XDocument.Load(filePath);
var schemaElement = doc.Element("schema");
foreach (var xElement in schemaElement.Elements())
    {
        Console.WriteLine(xElement.Attribute("name").Value + ":" + xElement.Attribute("value").Value);
    }

Elements method returns all elements inside schema element.

However I suggest changing xml file to this format, if possible

<?xml version="1.0" encoding="UTF-8"?>
<schema>
<KeyValuePair name="sp_transaction_id" value="1" />
<KeyValuePair name="sp_year" value="2015" />
<KeyValuePair name="sp_first_name" value="James" />
<KeyValuePair name="sp_gender" value="Male" />
<KeyValuePair name="sp_date_of_birth" value="06-06-1999" />
</schema>

Answer 4

You can load the files into an XDocument & then use Linq-To-XML to extract the required information. The example code below loads all name/value pairs into an array of class :

class MyXMLClass
{
  public String FieldName { get; set; }
  public String Value { get; set; }
}

The code gets all "schema" descendants (just one as it is the top level element), then selects all elements inside the & creates a new class object for each extracting the name & value.

  XDocument xd = XDocument.Load("test.xml");
  MyXMLClass[] xe =
    xd.Descendants("schema")
      .Elements()
      .Select(n => new MyXMLClass {FieldName = n.Attribute("name").Value, Value = n.Attribute("value").Value})
      .ToArray();