Linq查询:-从嵌套列表(对象数组)中查找记录

Question

我有实体程序。

Class Program
{
public int Id {get;set;}
public string ProgramName {get;set;}
public List<Activity> Activities {get;set}
}

活动看起来像：-

Class Activity
{
public int Id {get;set;}
public string Name {get;set;}
}

现在，我需要获取活动Id=参数Id的所有程序。

这就是我尝试的var programs = _context.Program.Where(p => p.Activities.Select(a => a.Id).Contains(Id)).ToList();

但它给出了类似的错误

"The LINQ expression 'DbSet<Programs>rn    .Where(p => p.LocationId == __model_Tags_0 || p.Activityrn        .Select(a => a.Id)rn        .Contains(__model_Tags_0) && True)' could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to either AsEnumerable(), AsAsyncEnumerable(), ToList(), or ToListAsync().

解决这个问题的更好方法(linq查询(是什么？

Answer 1

您可以在Where条件中使用类似于p.Activities.Any(a => a.Id == Id)的Any，如下所示。

var programs = _context.Program.Where(p => p.Activities.Any(a => a.Id == Id)).ToList();