public class Entity
{

    public int PrimaryKey;

}
public class Repository
{
    protected DbConnection Context;

    protected Repository(DbConnection context)
    {
        Context = context;
    }
}

interface IRepository<TEntity> where TEntity : Entity
{
    void Insert(TEntity entity);
    void Update(TEntity entity);
    void Delete(TEntity entity);
}

public class BookRepository : Repository, IRepository<Book>
{
    public BookRepository(DbConnection context) : base(context){}

    public void Insert(Book entity) { }

    public void Update(Book entity) { }

    public void Delete(Book entity) { }
}
public class Book : Entity
{

    public Book() { }
}

public class BookMarketRepositoy : Repository, IRepository<BookMarket>
{
    public BookMarketRepositoy(DbConnection context) : base(context){}

    public void Insert(BookMarket entity) { }


    public void Update(BookMarket entity) { }


    public void Delete(BookMarket entity) { }

}
public class BookMarket : Entity
{
    public BookMarket() { }
}

public class DbContext
{
    private DbConnection _conn;
    public BookMarketRepositoy BookMarkets { get; private set; }
    public BookRepository Books { get; private set; }

    public DbContext(DbConnection conn)
    {
        _conn = conn;
        if (_conn.State != ConnectionState.Open)
        {
            _conn.Open();
        }
        BookMarkets = new BookMarketRepositoy(conn);
        Books = new BookRepository(conn);
    }
}