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CSV to Cascading Model using Entity Framework

I need to turn an automatic CSV file into multiple database columns using Entity Framework. It is set up so that each model has children. So that Animal contains a list of Types which contain a list of Classification. In this way Classification is a grandchild of Animal
Right now I have these three models that need to be filled by the CSV file. The file is formatted in the following way:
They are then pulled from the API into a Windows Desktop App as a cascading dropdown box. So far I've tried adding them to separate lists however that did not upload when using Entity Framework. The current way is to try to cascade down the list however I get an error
Sequence contains no events
Here is the portion of the code that I am having a problem with (had to edit due to work rules so classes are different):
var Animal = new List<AnimalModel>();
var lines = await ReadStreamAsync(new StreamReader(uploadModel.File.OpenReadStream()));
foreach(string l in lines)
{
Animal.Add(new AnimalModel
{
AnimalName = cells[0],
});
Animal.Last().Type.Add(new TypeModel
{
TypeName = cells[1],
});
Animal.Last().Type.Last().Classification.Add(new ClassificationModel
{
Type = Type.Last(),
ClassificationName = cells[2],
Color = cells[3],
Age = cells[4]
});
}

I resolved the issue. I needed to initialize the list within the code as I am not doing so within the model. The following worked:
var Animal = new List<AnimalModel>();
var lines = await ReadStreamAsync(new StreamReader(uploadModel.File.OpenReadStream()));
foreach(string l in lines)
{
Animal.Add(new AnimalModel
{
AnimalName = cells[0],
Type = new List<TypeModel>()
{
new TypeModel()
{
TypeName = cells[1]
}
}
});
And so on for the grandchild. I will have to clean this up as it is quite messy but this works for now.

Store new XML into existing Project Array with Constructor

I'll try to keep it short and thank you in advance.
I have created a Quiz. The Questions and answers, as well as the integer for the correct answer are done via get and set , into a constructor and then created in another class by just creating an object and giving it the parameters. it looks as follows:
allQuestions = new Question[3];
allQuestions[0] = new Question("Question1", "answer1", "answer2",
"answer3", "answer4", 2);
where 2 is the integer that says answer 2 is the correct one.
i do use this array in almost every function in my code.
Now i decided to get the questions from a XML Document instead of creating them here. I'm a C# beginner so i played around and could not get it working.
my self made xml looks as follows :
<questions>
<question>
<ID>1</ID>
<questiontext>Peter</questiontext>
<answer1>der</answer1>
<answer2>da</answer2>
<answer3>21</answer3>
<answer4>lol</answer4>
</question>
<question>
<ID>2</ID>
<questiontext>Paul</questiontext>
<antwort1>dasistid2</antwort1>
<antwort2>27</antwort2>
<antwort3>37</antwort3>
<antwort4>47</antwort4>
</question>
</questions>
so 2 basic nodes (?)
can you explain me how to read that one and store it into my array so i can still use my e.g. "allQuestions.Question1" ? watched a youtube tutorial, quite a lot, could still not get it working in this project.
using visual studio 2017 , WPF , C#

There are a lot of ways to do what you are trying to do. I'll give you a dirty example of a manual solution, as well as a more automatic one that should work. Note that the automatic version won't use your constructor so unless you have an empty constructor defined it may not work for you.
Manual processing using XML Linq:
public IList<Question> ParseXml(string xmlString)
{
var result = new List<Question>();
var xml = XElement.Parse(xmlString);
var questionNodes = xml.Elements("question");
//If there were no question nodes, return an empty collection
if (questionNodes == null)
return result;
foreach (var questionNode in questionNodes)
{
var idNode = questionNode.Element("ID");
var textNode = questionNode.Element("questiontext");
var ant1Node = questionNode.Element("antwort1");
var ant2Node = questionNode.Element("antwort2");
var ant3Node = questionNode.Element("antwort3");
var ant4Node = questionNode.Element("antwort4");
var question = new Question();
question.Id = Convert.ToInt32(idNode?.Value);
// note the '?.' syntax. This is a dirty way of avoiding NULL
// checks. If textNode is null, it returns null, otherwise it
// returns the textNode.Value property
question.Text = textNode?.Value;
question.AnswerOne = ant1Node?.Value;
question.AnswerTwo = ant2Node?.Value;
question.AnswerThree = ant3Node?.Value;
question.AnswerFour = ant4Node?.Value;
result.Add(question);
}
return result;
}
Next we have the XmlSerializer approach. This is not ideal in all situations, but provides an easy way to serialize objects into XML and to deserialize XML into objects.
public QuestionCollection autoparsexml(string xml)
{
//create the serializer
XmlSerializer serializer = new XmlSerializer(typeof(QuestionCollection));
//convert the string into a memory stream
MemoryStream memStream = new MemoryStream(Encoding.UTF8.GetBytes(xml));
//deserialize the stream into a c# object
QuestionCollection resultingMessage = (QuestionCollection)serializer.Deserialize(memStream);
}
public class QuestionCollection
{
public List<Question> Questions { get; set; }
}

Couchbase Lite 2 + JsonConvert

The following code sample writes a simple object to a couchbase lite (version 2) database and reads all objects afterwards. This is what you can find in the official documentation here
This is quite a lot of manual typing since every property of every object must be transferred to the MutableObject.
class Program
{
static void Main(string[] args)
{
Couchbase.Lite.Support.NetDesktop.Activate();
const string DbName = "MyDb";
var db = new Database(DbName);
var item = new Item { Name = "test", Value = 5 };
// Serialization HERE
var doc = new MutableDocument();
doc.SetString("Name", item.Name);
doc.SetInt("Value", item.Value);
db.Save(doc);
using (var qry = QueryBuilder.Select(SelectResult.All())
.From(DataSource.Database(db)))
{
foreach (var result in qry.Execute())
{
var resultItem = new Item
{
// Deserialization HERE
Name = result[DbName].Dictionary.GetString("Name"),
Value = result[DbName].Dictionary.GetInt("Value")
};
Console.WriteLine(resultItem.Name);
}
}
Console.ReadKey();
}
class Item
{
public string Name { get; set; }
public int Value { get; set; }
}
}
From my research Couchbase lite uses JsonConvert internally, so there might be a way to simplify all that with the help of JsonConvert.
Anything like:
var json = JsonConvert.SerializeObject(item);
var doc = new MutableDocument(json); // No overload to provide raw JSON
or maybe
var data = JsonConvert.SerializeToDict(item); // JsonConvert does not provide this
var doc = new MutableDocument(data);
Is there or is this some kind of optimization and the preferred approach is by intend?

People ask about this quite often, but Couchbase Lite does not actually store JSON strings in the database. They are stored in a different format so this would not give the benefit that you think (the JSON would need to be reparsed and then broken down into the other format). I'd been pushing for a way to serialize classes directly instead of going through dictionary objects (which seems like the ultimate goal here) but our priority is on things that enterprise clients want and this doesn't seem to be one of them. Note that for it to make it in, it needs to be implemented in C# Java and Objective-C / Swift.

I don't know about JsonConvert but there seems to be a constructor that takes IDictionary<string, object> as argument. So I would try something like this (brain-compiled):
MutableDocument CreateDocument(object data)
{
if (data == null) return null;
var propertyValues = new Dictionary<string, object>();
foreach (var property in data.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance))
{
propertyValues[property.Name] = property.GetValue(data);
}
return new MutableDocument(propertyValues);
}
See if this works.

Reading files from a txt file and placing contents in a List<T>

I have a file in my project folder containing the data for properties in a Vehicle class. If the class was hardcoded into the XAML it would look like this:
Vehicle v1 = new Car() { Make = "Ford", Model = "Fiesta", Price = 10000, Year = "1999", Colour = "Red", Mileage = 40000, Description = "Lovely red car, 4 wheel, optional steering wheel.", VehicleType = "Car" };
VehicleList.Add(v1);
I don't want to hardcode this class object in, Instead I want to read it from a .txt file, each part separated by a comma ',' and place these into each property and add that vehicle into the Vehicle List<> 'VehicleList' and then display this new read list into a listbox.
Both the hardcode and the .txt follow the same structure with the hardcode containing the variable names and the .txt file containing just the data.
Here is what I have so far, as you can see I tried using System.IO however I am open to alternative methods.
private void Button_Click(object sender, RoutedEventArgs e)
{
string location = #"PATH";
VehicleList = File.ReadAllLines(location).ToList();
var logFile = File.ReadAllLines(location);
foreach (var v[i] in logFile) VehicleList.Add(s);
}
}

public static List<Car> FromTextFile(string fileName)
{
var lines = File.ReadAllLines(fileName);
var cars = new List<Car>();
foreach (var line in lines)
{
var car = FromLine(line);
if (car == null)
continue;
cars.Add(car);
}
return cars;
}
private static Car FromLine(string line)
{
var values = line.Split(',');
if (values.Length != 8) // There is no specification on what to do, if the amount of items is not sufficient.
return null;
// There is also no specification on what order to use, or how to map the ordering.
return new Car
{
Make = values[0],
Model = values[1],
// There is also no specification on how to handle in-correct formats.
// This assumes the Price property to be type of int.
Price = int.Parse(values[2]),
Year = values[3],
Colour = values[4],
// Again; how to handle in-correct formats?
Mileage = int.Parse(values[5]),
Description = values[6],
VehicleType = values[7]
};
}
This code should do what you described. Please be aware of the limitations of this code;
It expects a file that contains some lines, in comma seperated format.
It expects lines to contain 8 non-empty items, otherwise those lines will not be mapped.
It assumes the comma-seperated items to be exactly in this order; Make, Model, Price, Year, Colour, Mileage, Description, VehicleType.
It will not handle in-correct formats for converted types (e.g int). Because you did not ask so.
Keep in mind that this is not a desired code, it is not well written.
Now, as to your code;
Firstly, you've two different values for lines. I don't know why. One of them should be ok.
Second, you try to loop through one of them using foreach, but it doesn't work like that. You don't give or take an index from the foreach loop. The correct what is just foreach (TYPE VARIABLE_NAME in COLLECTION). So your code would be foreach (var v /* not v[i] */ in logFile) // ...
And then you add this to a list which contains those seperated lines again. At the end of the day, you have a list that contains the same lines twice. What you should have done in the adding part is, you should have converted the line to a Car object. Now how you do that, is absolutely up to you. Here are some question that comes to my mind, when the task is something such as mapping a string collection to an object.
What do I do if some members do not exist? (i.e when there is 5 items in the line, even though we have 8 properties)
How do I know which property to map the i'th item? What is the ordering? Do I get it from a "Columns" line? Do I just assume some ordering of my desire? How do I handle, if the user does not follow those rules?
What do I do, when there is something wrong about formatting of some of the members?
Now, this is not really an un-common problem. Everyone somehow needs to transport the data from place A to place B. For your specific instance, it is from disk storage, to memory, in the form of an object.
How do people solve these sorts of problem? They invent generic ways of "serialization" and "deserialization". What are some examples? The most known ones and the most used ones that comes to my mind are XML (eXtensible Markup Language) and JSON (JavaScript Object Notation). What do these actually do? They serialize programming objects to non-binary string formats. Here is an example XML output for your Car class.
<?xml version=\"1.0\" encoding=\"utf-16\"?>
<Car xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\">
<Make>Ford</Make>
<Model>Fiesta</Model>
<Price>10000</Price>
<Year>1999</Year>
<Colour>Red</Colour>
<Mileage>40000</Mileage>
<Description>Lovely red car, 4 wheel, optional steering wheel.</Description>
<VehicleType>Car</VehicleType>
</Car>
Generated with this simple code;
var car = new Car
{
Make = "Ford",
Model = "Fiesta",
Price = 10000,
Year = "1999",
Colour = "Red",
Mileage = 40000,
Description = "Lovely red car, 4 wheel, optional steering wheel.",
VehicleType = "Car"
};
var serializer = new XmlSerializer(typeof(Car));
// https://stackoverflow.com/questions/2434534/serialize-an-object-to-string
using (StringWriter textWriter = new StringWriter())
{
serializer.Serialize(textWriter, car);
var output = textWriter.ToString();
}
And this is, how you would easily read "Car"s from a text file, if it was formatted correctly;
var serializer = new XmlSerializer(typeof(List<Car>));
// If your file should contain one car and one car only, you should change the above line to;
// var serilizer = new XmlSerializer(typeof(Car));
using (var reader = File.OpenRead(#"PATH"))
{
var cars = (List<Car>)serializer.Deserialize(reader);
reader.Close();
}
Similar code can be written for JSON. But I think you get the idea.
In short, most of the times, XML, JSON or a similar generic format is sufficient. When they are not, you can develop your very own format. But comma-seperated line is a very simplistic way of doing serialization. The reasons are exactly my question (see above). And XML, JSON answers those questions easily. Implementations do a very good job as well, most of the time.
Edit
Here is an answer to a very similar question. The answer to that question would high likely also answer your question. How to split csv whose columns may contain ,

Deserialize string of name=value format to object

I want to read files, each of which contains a person's details, as below, and convert it to a Person object.
Covert below
id=1
firstName=John
lastName=Smith
To:
public class Person
{
public int Id {get;set;}
public string FirstName{get;set;}
public string LastName{get;set;}
}
Are there .NET built-in methods to do that, or third party library. I cannot find it via google.
Update:
The file format CANNOT be changed.

.NET is really into XML, so you won't find build-in functionality for INI-like formats. But there are a bunch of libs that make it easy to read and write such files, e.g. ini-parser or nini, but you still have to do the mapping to and from objects manually.

You could parse the text with String.Split and LINQ:
Dictionary<string, string> dict = text
.Split(new[] { Environment.NewLine }, StringSplitOptions.None)
.Select(e => e.Split('='))
.ToDictionary(strings => strings[0], strings => strings[1]);
Then use something like Dictionary Adapter.

For example using File.ReadAllLines, a little bit of Linq and String.Substring?
var lines = File.ReadAllLines(path).Select(l => l.Trim());
var idLine = lines.FirstOrDefault(l => l.StartsWith("id=", StringComparison.OrdinalIgnoreCase));
var lNameLine = lines.FirstOrDefault(l => l.StartsWith("lastname=", StringComparison.OrdinalIgnoreCase));
var fNameLine = lines.FirstOrDefault(l => l.StartsWith("firstname=", StringComparison.OrdinalIgnoreCase));
if (idLine != null && lNameLine != null && fNameLine != null)
{
Person person = new Person()
{
Id = int.Parse(idLine.Substring(idLine.IndexOf("=") + 1)),
FirstName = fNameLine.Substring(fNameLine.IndexOf("=") + 1),
LastName = lNameLine.Substring(lNameLine.IndexOf("=") + 1)
};
}
(assuming that there's just one person per file)
But i would use a different format like XML (or a database of course).

I really think you should consider changing your input data format into something more standard (like XML or JSON).
But that does not mean you can't read your file at all. You should just read your text file by your own:
var people = new List<Person>();
using (var stream = File.OpenRead("Input.txt"))
{
using (var reader = new StreamReader(stream))
{
while (!reader.EndOfStream)
{
int id = int.Parse(reader.ReadLine().Substring(3));
string firstName = reader.ReadLine().Substring(10);
string lastName = reader.ReadLine().Substring(9);
var newPerson = new Person()
{
Id = id,
FirstName = firstName,
LastName = lastName
};
people.Add(newPerson);
}
}
}

If you have the data in a format like this:
<Person>
<Id>1</Id>
<FirstName>John</FirstName>
<LastName>Smith</LastName>
</Person>
Then this C# code will desrialise into an instance of Person
//assuming you have a string called "data" that contains the above XML.
XDocument xd=XDocument.Parse(data); //needs System.Xml.Linq for XDocument type.
using(var reader = xd.CreateReader())
{
using(XmlSerializer ser = new XmlSerializer(typeof(Person))
{
Person p = ser.Deserialize(reader) as Person;
//p will be null if it didn't work, so make sure to check it!
}
}
Note that the deserializer is case sensitive so you need to make sure the element cases match the casing of the properties in your class (You can get arond this by decorating your properties with Serializer attributes that tell the serialzer how to map them here)
The plain native serialzer is great for simple objects like this but can trip you up on some data types like char, bool, etc, so do checkout that link on the attributes.
If you wanted to do it from the format you gave in the question, you'd need to write a custom serialiser, in your case my advice would be to read from your file and generate XML from the data using XDocument Hope that helps.