建立一对多关系

Question

I am trying to create a one ( Project ) to many ( ActionLog ) relationship between the following tables:

public class Projects {
    [Key]
    public int Id { get; set; }
    public string Name { get; set; } //I cut out most of the props as they were not relevant
   }

//They exist in two different .cs files. 

public class ActionLog {
     [Key]
     public int Id { get; set;}
     public string Information {get; set;}
     public ProjectsId {get; set;}
   }

Currently, in my viewmodel, I am doing a linq select for all entries that match my ProjectTableId and putting it into a list for each instance of Project .

I fear that this approach is extremely inefficient as it queries the database for every single entry of Projects. I know eager(?) loading would be best in this case, but I don't know how to implement it.

Tables can look like this: (Structure-wise) * Again the actual tables are necessarily complicated, so I cut out the unnecessary props for simplicity sake.

Answer 1

Traditionally, you'd have an ICollection of your many-related items:

public class Project
{
    ...

    public virtual ICollection<ActivityLog> ActivityLogs { get; set; }
}

With that, then, you can include the logs when querying the projects:

var projects = db.Projects.Include(m => m.ActivityLogs)