How to determine where the database with which the applicati

Question

How to determine where the database with which the application works is located?
I launch the application.
The application adds and receives entries.
The application adds and receives records to another database, and not to which the connection is made in the code.
I can’t understand what database the application works with.
 
Category.cs

//
using System.Collections.ObjectModel;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace WpfAppFrm
{
    [Table("Categories")]
    public class Category
    {
        public Category()
        {
            // this.Products = new ObservableCollection<Product>();
        }

        public int CategoryId { get; set; }
        public string Name { get; set; }

        // public virtual ObservableCollection<Product> Products { get; private set; }

    }
}

ProductContext.cs

//
using System.Data.Entity;

namespace WpfAppFrm
{
    public class ProductContext : DbContext
    {
        // public ProductContext() : base("DefaultConnection")
        public string ConnectionString_test { get; set; }
        public ProductContext(string ?onnectionString)
        {
            this.ConnectionString_test = ?onnectionString;
        }

        public DbSet<Category> Categories { get; set; }
        // public DbSet<Product> Products { get; set; }
    }
}

MainWindow.xaml.cs

//
using System.ComponentModel;
using System.Data.Entity;

namespace WpfAppFrm
{
    /// <summary>
    /// ?????? ?????????????? ??? MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        // public static string ?onnectionString = @"C:\test\DB\NorthwindC.mdf";
        public static string ?onnectionString = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\test\DB\NorthwindC.mdf;Integrated Security=True;Connect Timeout=30";
        // public static string ?onnectionString = @"Data Source=(localdb)\mssqllocaldb;Initial Catalog=WpfAppFrm.ProductContext;Integrated Security=True;  MultipleActiveResultSets=True";
        private ProductContext _context = new ProductContext(?onnectionString);

        public MainWindow()
        {
            InitializeComponent();
        }


        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            try
            {
                System.Windows.Data.CollectionViewSource categoryViewSource =
                ((System.Windows.Data.CollectionViewSource)(this.FindResource("categoryViewSource")));

                _context.Categories.Load();

                BindingList<Category> _studBindList = _context.Categories.Local.ToBindingList();

                categoryViewSource.Source = _context.Categories.Local;

                // AddEntity();
                // GetAll();
                string connectionString_str = _context.Database.Connection.ConnectionString;
                string connectionString_str2 = _context.ConnectionString_test;
            }
            catch (Exception ex)
            {
                throw;
            }
        }

        public void AddEntity()
        {
            Category category = new Category
            {
                Name = "Name_Category_4"
            };

            _context.Categories.Add(category);
            _context.SaveChanges();
        }

        public void GetAll()
        {
            _context.Categories.Load();

            BindingList<Category> _studBindList = _context.Categories.Local.ToBindingList();
        }
    }
}

MainWindow.xaml

<Window x:Class="WpfAppFrm.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfAppFrm"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="334.874" Loaded="Window_Loaded">
    <Window.Resources>
        <CollectionViewSource x:Key="categoryViewSource"
                                d:DesignSource="{d:DesignInstance {x:Type local:Category}, CreateList=True}"/>
        <CollectionViewSource x:Key="categoryProductsViewSource" Source="{Binding Products, Source={StaticResource categoryViewSource}}"/>
    </Window.Resources>
    <Grid DataContext="{StaticResource categoryViewSource}" Margin="0,0,7,0">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="33*"/>
            <ColumnDefinition Width="287*"/>
            <ColumnDefinition Width="0*"/>
            <ColumnDefinition Width="0*"/>
        </Grid.ColumnDefinitions>
        <DataGrid x:Name="categoryDataGrid" AutoGenerateColumns="False" EnableRowVirtualization="True"
                    ItemsSource="{Binding}" Margin="13,13,3,257"
                    RowDetailsVisibilityMode="VisibleWhenSelected" Grid.ColumnSpan="2">
            <DataGrid.Columns>
                <DataGridTextColumn x:Name="categoryIdColumn" Binding="{Binding CategoryId}"
                                    Header="CategoryId" Width="SizeToHeader"/>
                <DataGridTextColumn x:Name="nameColumn" Binding="{Binding Name}"
                                    Header="Name" Width="SizeToHeader"/>
            </DataGrid.Columns>
        </DataGrid>

    </Grid>
</Window>

TABLE [dbo].[Categories]

CREATE TABLE [dbo].[Categories] (
[CategoryId] INT           IDENTITY (1, 1) NOT NULL,
[Name]       NVARCHAR (40) NULL,
PRIMARY KEY CLUSTERED ([CategoryId] ASC)