Clearing and removing data from table? C#

So i've managed with some help to write and retrieve "info" from data file.
BUT i dont know how to:
1. Clear all the data file.
2. Remove a single line (for example the written earlier steamid)

Thanks for any help.

 

Forgot to mention.. that i need c# example

I will check the lua ones and like "convert" them to c#
Nah.. still no luck. But i will wait for C# ex.

 

Are you using MySQL/SQLite or just a JSON file?

 

Json file

 

I don't know how you are storing an information. But i can show you my example.
I have HashSet of objects.

Code:

class StoredData
{
    public HashSet<Player> Players = new HashSet<Player>();    public StoredData() {}
}class Player
{
    public ulong Id;
    public int   Count = 0;    public Player() {}   public Player(ulong id)
   {
      Id = id;
   }
}

When plugin is loaded I'm loading my JSON.

Code:

StoredData data = Interface.GetMod().DataFileSystem.ReadObject<StoredData>("myData");

When I want to delete data from file I'm do this.

Code:

foreach (Player p in data.Players)
{
    if (p.Id == "whateverID_1209843")
    {
        data.Players.Remove(p);
    }
}

Then I'm saving data in file.

Code:

Interface.GetMod().DataFileSystem.WriteObject("myData", data);