最近日期的LINQ加入lambda

我正在尝试对表“Personen”和联接表“Leners”进行linq查询。
从“Leners”桌上,如果有最新的商品,我想要。

在SQL中,我会这样做:

select p.*, l.* 
from dbo.Personen p
left outer join dbo.Leners l on l.LenerId = 
    (select top 1 LenerId 
     from dbo.Leners lt
     where lt.PersoonId = p.PersoonId 
     order by lt.Vanaf desc)

我怎么能用linq做到这一点? 我想在lambda表达式中这样做,因为它依赖于一个选择。

using (var db = new DbContext())
{
    var query = from p in db.Personen                        
                select p;

    if (someSelection != null)
    {
        query = ?
    }
}

以下是表格:(EF代码优先)

[Table("Personen")]
public class Persoon
{
    [Key]
    public int PersoonId { get; set; }

    [StringLength(50)]
    [Required]
    public string Naam { get; set; }
}

[Table("Leners")]
public class Lener
{
    public int LenerId { get; set; }

    public int? PersoonId { get; set; }

    [ForeignKey("PersoonId")]
    public virtual Persoon Persoon { get; set; }

    public DateTime Vanaf { get; set; }
}