Entity Framework extra properties are not populated by DbContext.Database.SqlQuery

Question

When I add extra properties to a EF auto-generated class by using an extra partial class, these properties are not populated or filled when running queries against the database.

Example:

Auto-Generated class Person:

public partial class Person
{
    public string Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

My own partial class

public partial class Person
{
    public string DisplayName{ get; set; }
}

When I make the following query:

"SELECT *, (FirstName + LastName) AS DisplayName FROM [Person]"

and use

DbContext.Database.SqlQuery(typePerson, SQL, null)

the Id, FirstName and LastName are populated but not the DisplayName.

However when I create a whole new class called MyPerson

public partial class MyPerson
{
    public string Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string DisplayName{ get; set; }
}

And run the same query with the type of MyPerson the DisplayName is populated as well.

Can anyone explain this or tell me how I can fix this problem so I can use Partials instead of having to create new classes/types.

Download an example: https://www.dropbox.com/s/dayrv0jzuoju9q3/StackOverflow_EF_ExtraProperties.zip?dl=0

UPDATE 2015-12-28: While reading through other stackoverflow and Codeproject forums I found another ways to get it to work:

1) Using Typebuilder (http://www.codeproject.com/Articles/206416/Use-dynamic-type-in-Entity-Framework-SqlQuery) but due to all sort of project dependencies I had problems finding already created types and not blowing up the memory;

2) Best option so far: using inheritance.

When I create another class with just this lines:

class Person_Reflect : Person { }

I can use the following code (it will ignore the mapping in the EDMX file and use reflection:

List<EF.Person> listPerson = dbEntities.Database.SqlQuery<EF.Person_Reflect>(sql, new object[] { }).ToList<EF.Person>();

Are you sure the 2nd partial class of Person is in the right namespace? — Alexander Derck
– Alexander Derck, Commented Dec 24, 2015 at 8:17
Thx for all your comments! Yes in the same namespace. "No exception"? Can you elaborate on your comment? Yes I see the Displayname as a property with value NULL. — LiQuick.net
– LiQuick.net, Commented Dec 24, 2015 at 9:13
I have never tried Model-first with EF. But for this particular problem, I would make: public partial class Person { public string DisplayName{ get { return FirstName + LastName; } } } — droidbot
– droidbot, Commented Dec 24, 2015 at 11:48

LiQuick.net · Accepted Answer · 2016-01-04 10:40:26Z

2

Best option so far without having to code much and or to do much code review when Database changes occur is to use inheritance.

When I create another class with just this line:

class Person_Reflect : Person { }

I can use the following code (it will ignore the mapping in the EDMX file and use reflection):

List<EF.Person> listPerson = dbEntities.Database.SqlQuery<EF.Person_Reflect>(sql, new object[] { }).ToList<EF.Person>();

answered Jan 4, 2016 at 10:40

LiQuick.net

19916 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Seabizkit · Accepted Answer · 2015-12-24 11:45:33Z

0

try remove the *

@"
 SELECT 
     Id 
    ,FirstName 
    ,LastName 
    ,(FirstName + ' ' + LastName) AS DisplayName 
 FROM [Person]"

Alternatively you could do this is code... and then you would not need to include it in your raw sql

public string DisplayName { get { return FirstName+ " " +LastName ; } }

edited Dec 24, 2015 at 11:45

answered Dec 24, 2015 at 11:38

Seabizkit

2,4152 gold badges17 silver badges33 bronze badges

5 Comments

LiQuick.net Over a year ago

Leaving out the * doesn't work, it even makes it worse; if I forget one column the application ends with the exception: The data reader is incompatible with the specified 'Application.Person'. A member of the type, 'COLUMNNAME', does not have a corresponding column in the data reader with the same name. You are absolutely right, your coding solution solves this example but I have a dynamic query that can be enriched on runtime to create a multitude of end user choices of how to display/format results. So I only have a view options: using evals or creating dynamic queries.

Seabizkit Over a year ago

it should work... the column must be the same CASE and data type. I have done something simular myself so i know it works.. please double check case and types

LiQuick.net Over a year ago

Dear Seabizkit. I have uploaded a test example in which I can't seem to get it to work what you have accomplished. The link to the full example is: dropbox.com/s/dayrv0jzuoju9q3/…

Seabizkit Over a year ago

FFS why was this down voted. OMG really are people so.... ish @LiQuick.net ill double check myself later.... when im back at work.

LiQuick.net Over a year ago

Sorry for the downvoting not my doing.

Collectives™ on Stack Overflow

Entity Framework extra properties are not populated by DbContext.Database.SqlQuery

2 Answers 2

Comments

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related