tama Posts - Answer Overflow

tama

•Created by tama on 6/10/2024 in #help

How does EF know what database to use?

Hello there. I am building an entity related management system, and I'm wondering how EF know what database I want it to use. I am using .Net 8, and the only place I have referenced the database was in the Program.cs file, however, I have commented out that part and it is still able to update my database. How is that possible?

19 replies

CC#

•Created by tama on 6/9/2024 in #help

✅ Required property

Hello there. I am creating a class with some required properties. I have decorated them with the [Required] thing, however, it's still complaining. Are you supposed to have both [Required] and the required keyword? Example:

C#
public class A
{
  [Required]
  public string Name { get; set; }
}

C#
public class A
{
  [Required]
  public string Name { get; set; }
}

Should it be this instead?:

C#
public class A
{
  [Required]
  public required string Name { get; set; }
}

C#
public class A
{
  [Required]
  public required string Name { get; set; }
}

11 replies

CC#

•Created by tama on 6/9/2024 in #help

Project requirements?

Hello there. I am about to publish a project I have written, however, I am little unsure how you usually handle libraries when publishing the project. In Python, you usually have a requirements.txt file listing all the libraries used by the project. How do you do that in C#? I want to ensure the recipient is able to run the project without having to look at the code.

4 replies

CC#

•Created by tama on 6/8/2024 in #help

Best practice for class constructors?

Hello there. I'm creating a class with one private and one public variable. I am a little unsure how the constructor should work when this is the case. As an example:

C#
public class A
{
  private readonly typeX _var1;
  public typeY var2Something { get; set; }
  
  public A(typeX var1, typeY var2) 
  {
    _var1 = var1;
    var2Something = var2;
  }
}

C#
public class A
{
  private readonly typeX _var1;
  public typeY var2Something { get; set; }
  
  public A(typeX var1, typeY var2) 
  {
    _var1 = var1;
    var2Something = var2;
  }
}

Does it make sense to declare them first, and then assign them in the initializor? Also, are you supposed to add { get; set; } to the class variable when it's also part of the constructor? I am also unsure what the best practice is for variable names in C#. Some places I have seen names with capital first letter, other times I see something like exampleVariable. I come from Python, where we use _variable_name for private variables, do you also use the underscore in C#?

8 replies

CC#

•Created by tama on 6/7/2024 in #help

Entity DB object with immutable variables

Hello there. I am kind of new to C# and I am doing a project about some database management system. I have created an object for the database and my first migration went well. Now, part of the challenge with this project is that some class variables for the database object needs to be readonly after being set in the initializer. I am a little unsure if this is something you can achieve with some keywords or if I need to create my own logic for ensuring the fields are never changed. As an example: I have a class Car with three variables: Manufacturer, Model and Owner. Now, Manufacturer and Owner will always stay the same for the object in the database but Owner can of course change. To achieve this, I have so far written:

C#
public class Car
{
    private string _manufacturer;
    private string _modelName;

    public string Manufacturer => _manufacturer;
    public string ModelName => _modelName;

    [Required]
    public string Owner { get; set; }

    public Car(string manufacturer, string modelName, string owner)
    {
        _manufacturer = manufacturer;
        _modelName = modelName
        Owner = owner;
    }
}

C#
public class Car
{
    private string _manufacturer;
    private string _modelName;

    public string Manufacturer => _manufacturer;
    public string ModelName => _modelName;

    [Required]
    public string Owner { get; set; }

    public Car(string manufacturer, string modelName, string owner)
    {
        _manufacturer = manufacturer;
        _modelName = modelName
        Owner = owner;
    }
}

Is this sufficient?

18 replies

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