C# 实体框架虚拟ICollection如何查询

首先，我不熟悉实体框架等，并试图弄明白一些事情。我有一个这样的模型：

 public class EventInstance {

    [Column("EVENT_INSTANCE_ID")]
    public int EventInstanceID { get; set; }

    [Column("CUSTOMER_ID")]
    public int CustomerID { get; set; }

    [Column("EVENT_ID")]
    public int EventID { get; set; }

    [Column("START_DATE_TIME")]
    public System.DateTime StartDateTime { get; set; }

    public virtual Event Event { get; set; }

}

 public IQueryable<EventInstance> GetInstances(int scheduleID) {
            // only returning instances that are 3 months back
            DateTime dateRange = DateTime.Now.AddDays(-180);
            return EventDBContext.EventInstances.Where
                (x => x.CustomerID == MultiTenantID && x.StartDateTime >= dateRange)
                .OrderBy(x => x.StartDateTime).AsQueryable();
        }

我需要访问名为EventTimeEventInstances的表中的属性，但该表不包括在模型中。我有两个问题

如果我加上：

public virtual ICollection<EventTimeEventInstance> EventTimeInstances { get; set; }

公共虚拟ICollection EventTimeInstances{get；set；}

这会影响我们应用程序的其他方面吗

其次，如何在如下查询中从ICollection访问属性：

 public class EventInstance {

    [Column("EVENT_INSTANCE_ID")]
    public int EventInstanceID { get; set; }

    [Column("CUSTOMER_ID")]
    public int CustomerID { get; set; }

    [Column("EVENT_ID")]
    public int EventID { get; set; }

    [Column("START_DATE_TIME")]
    public System.DateTime StartDateTime { get; set; }

    public virtual Event Event { get; set; }

}

 public IQueryable<EventInstance> GetInstances(int scheduleID) {
            // only returning instances that are 3 months back
            DateTime dateRange = DateTime.Now.AddDays(-180);
            return EventDBContext.EventInstances.Where
                (x => x.CustomerID == MultiTenantID && x.StartDateTime >= dateRange)
                .OrderBy(x => x.StartDateTime).AsQueryable();
        }

publicIQueryable GetInstances（int scheduleID）{
//仅返回3个月前的实例
DateTime dateRange=DateTime.Now.AddDays（-180）；
返回EventDBContext.EventInstances.Where
（x=>x.CustomerID==MultiTenantID&&x.StartDateTime>=dateRange）
.OrderBy（x=>x.StartDateTime）.AsQueryable（）；
}

---

我需要能够将EventTimeInstances.EventTimeID==scheudleID添加到此查询。我如何才能做到这一点？

您可以在查询中这样使用它：

public IQueryable<EventInstance> GetInstances(int scheduleID) 
{
    // only returning instances that are 3 months back
    DateTime dateRange = DateTime.Now.AddDays(-180);
    return EventDBContext.EventInstances.Where(x => 
            x.CustomerID == MultiTenantID && 
            x.StartDateTime >= dateRange && 
            x.EventTimeInstances.Any(a => a.EventTimeID == scheudleID) ).OrderBy(x => x.StartDateTime).AsQueryable();
}

publicIQueryable GetInstances（int scheduleID）
{
//仅返回3个月前的实例
DateTime dateRange=DateTime.Now.AddDays（-180）；
返回EventDBContext.EventInstances.Where（x=>
x、 CustomerID==MultiTenantID&&
x、 StartDateTime>=日期范围&&
x、 EventTimeInstances.Any（a=>a.EventTimeID==scheudleID））.OrderBy（x=>x.StartDateTime）.AsQueryable（）；
}