Entity Framework - Include multiple level properties

Question

I am trying to get a table from database using entity framework.

The table has reference to other table which again has reference to other tables. I know how to include other tables. And according to this answer and this MSDN page including multiple levels are like this:

entity.TableLevel1.Include(tLvl1=>tLvl1.TableLevel2.Select(tLvl2=>tLvl2.TableLevel3));

But my question is, how to include another table at level 3 ?

This seems not to work:

entity.TableLevel1
          .Include(tLvl1=>tLvl1.TableLevel2
               .Select(tLvl2=>tLvl2.TableLevel3)
               .Select(tLvl2 => tLvl2.AnotherTableLevel3);

Please show us the table class code.

James Dev
– James Dev

2016-02-26 15:22:41 +00:00
Commented Feb 26, 2016 at 15:22 — James Dev
– James Dev, Commented Feb 26, 2016 at 15:22

ocuenca · Accepted Answer · 2016-02-26 15:22:40Z

19

Add another Include call:

entity.TableLevel1.Include(tLvl1=>tLvl1.TableLevel2.Select(tLvl2=>tLvl2.TableLevel3))
                  .Include(tLvl1=>tLvl1.TableLevel2.Select(tLvl2=>tLvl2.AnotherTableLevel3));

If you want to load related entities that are at the same level you should call Include extension method for each of them.

answered Feb 26, 2016 at 15:22

ocuenca

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Comments

Arturo Menchaca · Accepted Answer · 2016-02-26 15:31:41Z

6

You can make multiple Include() calls:

entity.TableLevel1.Include(t1 => t1.TableLevel2);
entity.TableLevel1.Include(t1 => t1.TableLevel2.Select(t2 => t2.TableLevel3));
entity.TableLevel1.Include(t1 => t1.TableLevel2.Select(t2 => t2.AnotherTableLevel3));

or

entity.TableLevel1.Include("TableLevel2");
entity.TableLevel1.Include("TableLevel2.TableLevel3");
entity.TableLevel1.Include("TableLevel2.AnotherTableLevel3");

But you can mark your navigation properties as virtual and will be lazy loading, so you dont need to make the Include() calls:

class TableLevel1
{
    public virtual TableLevel2 TableLevel2 { get; set; }
}

class TableLevel2
{
    public virtual TableLevel3 TableLevel3 { get; set; }

    public virtual TableLevel3 AnotherTableLevel3 { get; set; }
}

answered Feb 26, 2016 at 15:31

Arturo Menchaca

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1 Comment

ocuenca Over a year ago

Arturo, there are two things I want to warn you about your solutions. The first thing is your first Include call is unnecessary, that level is going to be loaded with any of the other two Include calls. The second thing is if they want to use their entities in a place where its context was already disposed, lazy loading is not a option, an exception will be thrown.

AceSyntax · Accepted Answer · 2019-02-15 13:34:09Z

0

Using EF 6.2 (not core) this gave me a headache for a few hours, only to find that the reason this wasn't working...

.Include("InspectionResultsByPerspective") .Include("InspectionResultsByPerspective.InspectionResults") .Include("InspectionResultsByPerspective.InspectionResults.PreparationTasksResults")

was because the type PreparationTasksResults had no default ctor!!! ahhh!

Give it a default ctor and you can include to your heart's content :) or so it seems for me

answered Feb 15, 2019 at 13:34

AceSyntax

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1 Comment

Nawed Nabi Zada Over a year ago

This must be for code first approach. Nobody cares about constructors if database first approach is used.

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