使用ICollection从主要详细信息获取子详细信息中的一对多关系问题

Question

大家好日子，

我有2个模型，彼此之间有关系。一对多的关系

// Main model
public class MainDetails {
   [Key]
   public int MainDetailId { get; set; }
   public string Name { get; set; }
   public ICollection<SubDetails> SubDetails { get; set; }
}

// Sub model
public class SubDetails {
   [Key]
   public int SubDetailId{ get; set; }
   public string School { get; set; }

   public MainDetails MainDetails { get; set; }
   public int MainDetailId { get; set; }
}

现在这里是我的代码，我遇到了问题。

public IQuerable<MainDetails> SearchDetails(string school){
     return context.MainDetails.Where(details=>details.SubDetails.School == school) 
     // details.SubDetails.School is an ICollection so this not working.
}

public IQuerable<MainDetails> SearchDetails(string school){
     return context.MainDetails.Inclue(x=>x.SubDetails).Where(details=>details.SubDetails.School == school) 
     // This doesn't work too
}

为什么我无法获得SubDetails.School？还是要解决这个问题？

对不起，我在谈到关系时是新的。我希望你能和我分享一些。谢谢！

Answer 1

这段代码甚至不应该编译......

public IQuerable<MainDetails> SearchDetails(string school)
{
     return context.MainDetails.Where(details=>details.SubDetails.School == school) 
     // details.SubDetails.School is an ICollection so this not working.
}

你应该......

public IQuerable<MainDetails> SearchDetails(string school)
{
     return context
                .MainDetails
                .Where(details=> 
                    details.SubDetails.Any(sd => sd.School == school));
}