Correct query using Entity Framework

Question

I have two tables "Users" and "UserType". There is a relationship between these tables on "userTypeID" column. This column is primary key in the "UserType" table and foreign key in the "User" table. I also have a property in "User" class like follows:

public virtual UserType usertype{ get; set; }

I am querying "User" table like follows:

List<MyApp.Entity.Models.User> userList = new List<User>();
using (var DBContext = new UserDBContext())
{
userList  = DBContext.User.Where(x => x.IsActive == true).OrderBy(i => i.userName).ToList();
return userList;
}

When I am debugging the code, userList.usertype is null. I need to have the UserType in the userList. What am I doing wrong? I am new to Entity Framework.

You don't need to in initialize userList.You context returns that list. — Hamlet Hakobyan
– Hamlet Hakobyan, Commented Mar 28, 2014 at 13:33

CallumVass · Accepted Answer · 2014-03-28 14:14:36Z

1

Include at the top of your class:

using System.Data.Entity

Then modify your query like so:

userList  = DBContext.User
                .Include(u => u.usertype)
                .Where(x => x.IsActive)
                .OrderBy(i => i.userName)
                .ToList();

This is called Eager Loading. You can read more about it here: Loading Related Entities

edited Mar 28, 2014 at 14:14

answered Mar 28, 2014 at 13:31

CallumVass

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4 Comments

Raphaël Althaus Over a year ago

Hmmm, what you do is Eager, not Lazy loading.

Sergey Berezovskiy Over a year ago

Lazy loading is making additional queries to load related entities

Raphaël Althaus Over a year ago

And Lazy loading is no more available as soon as you dispose your context (as you do with your using clause)

CallumVass Over a year ago

Thanks for the correction. I've changed my answer to state that its Eager loading, not Lazy Loading :)

Loetn · Accepted Answer · 2014-03-28 13:32:52Z

1

You have to explicitly include your usertype.

userList  = DBContext.User
.Include("usertype")
.Where(x => x.IsActive == true).OrderBy(i => i.userName).ToList();

Or with lambda: Add using System.Data.Entity;

userList  = DBContext.User
.Include(x => x.usertype)
.Where(x => x.IsActive == true).OrderBy(i => i.userName).ToList();

answered Mar 28, 2014 at 13:32

Loetn

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