[英]Help with Linq to XML
Iv got two DB tables. iv有两个数据库表。 One containing types(Id, Name) and the other holds datapoints (RefId, Date, Value) that are referenced by the types. 一个包含类型(Id,名称),另一个包含类型所引用的数据点(RefId,日期,值)。 I need to create a XML file with the following strukture: 我需要使用以下结构创建一个XML文件:
<?xml version='1.0' encoding='utf-8' ?>
<root>
<type>
<name></name>
<data>
<date></date>
<temp></temp>
</data>
<data>
<date></date>
<temp></temp>
</data>
<data>
<date></date>
<temp></temp>
</data>
</type>
</root>
And iv got the following code to do this iv获得了以下代码来执行此操作
public XmlDocument HelloWorld()
{
string tmp = "";
try
{
sqlConn.ConnectionString = ConfigurationManager.ConnectionStrings["NorlanderDBConnection"].ConnectionString;
DataContext db = new DataContext(sqlConn.ConnectionString);
Table<DataType> dataTypes = db.GetTable<DataType>();
Table<DataPoints> dataPoints = db.GetTable<DataPoints>();
var dataT =
from t in dataTypes
select t;
var dataP =
from t in dataTypes
join p in dataPoints on t.Id equals p.RefId
select new
{
Id = t.Id,
Name = t.Name,
Date = p.PointDate,
Value = p.PointValue
};
string xmlString = "<?xml version=\"1.0\" encoding=\"utf-8\" ?><root></root>";
XmlDocument xmldoc = new XmlDocument();
xmldoc.LoadXml(xmlString);
int count = 0;
foreach (var dt in dataT)
{
XmlElement type = xmldoc.CreateElement("type");
XmlElement name = xmldoc.CreateElement("name");
XmlNode nameText = xmldoc.CreateTextNode(dt.Name);
name.AppendChild(nameText);
type.AppendChild(name);
foreach(var dp in dataP.Where(dt.Id = dp.RefId))
{
XmlElement data = xmldoc.CreateElement("data");
XmlElement date = xmldoc.CreateElement("date");
XmlElement temp = xmldoc.CreateElement("temp");
XmlNode dateValue = xmldoc.CreateTextNode(dp.Date.ToString());
date.AppendChild(dateValue);
XmlNode tempValue = xmldoc.CreateTextNode(dp.Value.ToString());
temp.AppendChild(tempValue);
data.AppendChild(date);
data.AppendChild(temp);
type.AppendChild(data);
}
xmldoc.DocumentElement.AppendChild(type);
}
return xmldoc;
}
catch(Exception e)
{
tmp = e.ToString();
}
return null;
}
[Table(Name="DataTypes")]
public class DataType
{
[Column(IsPrimaryKey = true)]
public long Id;
[Column]
public string Name;
}
[Table(Name="DataPoints")]
public class DataPoints
{
[Column]
public long RefId;
[Column]
public DateTime PointDate;
[Column]
public double PointValue;
}
This is not a working code. 这不是工作代码。 Im having problems with LINQ and the inner joins. 我在使用LINQ和内部联接时遇到问题。 Could someone please help me to get the correct strukture. 有人可以帮我得到正确的结构。 I hope its kinda clear what im trying to achive. 我希望它能清楚达到我想要达到的目标。
Best Regards Marthin 最好的问候马辛
var result =
new XDocument(new XElement("root",
from dt in dataTypes
join dp in dataPoints on dt.Id equals dp.RefId
select new XElement("type",
new XElement("name", dt.Name),
new XElement("data",
new XElement("date", dp.PointDate),
new XElement("temp", dp.PointValue)))));
var result =
new XDocument(new XElement("root",
from dt in dataTypes
select new XElement("type",
new XElement("name", dt.Name),
from dp in dataPoints
where dp.RefId == dt.Id
select new XElement("data",
new XElement("date", dp.PointDate),
new XElement("temp", dp.PointValue)))));
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