Entity framework with IN Clause in Repository Pattern - entity-framework

Question

I looking for some help on how to implement IN clause in the repository pattern. Rather than making single call for each and every record, I will have set of IDs, pass on this IDs to Context to get entities which satisfies the condition using Repository Pattern with EF.
I knew we can have something like this:
context.Students.Where( x => StudentIDs.contains(x.ID))
How to implement same in the repository layer or pattern with single call to DB?

Answer 1

If you really are a purist, yes you should abstract the DbContext entirely as you seem to imply.
I'm not sure I completely understand the issue, but something like that should do the job:
namespace EFRepo
{
class Student
{
public long Id { get; set; }
public string Name { get; set; }
}
class SchoolContext : DbContext
{
public DbSet<Student> Students { get; set; }
}
class SchoolRepository
{
private SchoolContext context = new SchoolContext();
public Student Add(string name)
{
Student student = new Student { Name = name };
context.Students.Add(student);
context.SaveChanges();
return student;
}
public IEnumerable<Student> GetStudentsByIds(IEnumerable<long> ids)
{
return context.Students.Where(x => ids.Contains(x.Id));
}
}
class Program
{
static void Main(string[] args)
{
SchoolRepository repo = new SchoolRepository();
repo.Add("Bully");
repo.Add("Crawler");
repo.Add("Tart");
foreach (Student s in repo.GetStudentsByIds(new[] { 1L, 3 }))
{
Console.WriteLine(s.Name);
}
}
}
}