public class File
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Location { get; set; }
    public ulong Size { get; set; }
}

public class FileManager
{
    public File CreateFile(byte[] fileData, string fileName)
    {
        const string FileDirectory = "./Files";

        var file = new File()
        {
            Name = fileName,
            Size = fileData.Length,
            Location = Path.Combine(FileDirectory, fileName)
        };

        File.WriteAllBytes(file, fileData);

        // Save File to your sql database, which only contains an id, the name, maybe the file size and the Location of your file ("./Files/YourFileName.txt")
        // You can then reference the File within whatever other database row you have via its id
        SaveFileToDatabase(file);

        return file;
    }
}

public class File
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Location { get; set; }
    public ulong Size { get; set; }
}

public class FileManager
{
    public File CreateFile(byte[] fileData, string fileName)
    {
        const string FileDirectory = "./Files";

        var file = new File()
        {
            Name = fileName,
            Size = fileData.Length,
            Location = Path.Combine(FileDirectory, fileName)
        };

        File.WriteAllBytes(file, fileData);

        // Save File to your sql database, which only contains an id, the name, maybe the file size and the Location of your file ("./Files/YourFileName.txt")
        // You can then reference the File within whatever other database row you have via its id
        SaveFileToDatabase(file);

        return file;
    }
}