DataSource Controls :: How To Create A Self Association Relation For An Organization Chart Data Tree In Entity Framework
Mar 6, 2010
I,am trying to create a self association relation for an organization chart data tree in Entity Framework,after trying different ways for prevention of exceptions like 3007 and etc. I found that when I put my foreign key in my POCO near Parent and Items navigation properties its work.but I think this is not correct that we have both ParentID scalar property and Parent navigation property. review this and tell me is it correct or not.I'm using VS 2010 RC and ofcource .net framework 4.0 RC
I have 3 tables 1-Category, 2-AssignToCategory, 3-User
Fields in Category (Id, CategoryName)
Fields in AssignToCategory (Id, CategoryId, UserId) -->CategoryName,UserId as forigen key
Fields in User (Id, Fullname)
There is no association defined just used forigen keys.Impoted in EF. Now I want to create association.
1 - Right Click on User and Category for association and 1 to many created UNCHECKING FK checkbox as foriden keys already defined. Relation created than double clicked on relation to assign Principal and Dependent key (Principal (User,Category) and Dependent is AssignToCategory). All done.
Error Error 1 Error 113: Multiplicity is not valid in Role 'User' in relationship 'UserAssignedToCategory'. Because all the properties in the Dependent Role are nullable, multiplicity of the Principal Role must be '0..1'. c:userslordalidocumentsvisual studio 2010ProjectsCodingCodingModelsCoding.edmx 93 11 Coding
Same error for Category.How do i create association if its not defined on imported tables.
SIDE NOTE: If I removed forigen keys from AssignToCategory and created an association with FK check box clicked so EF put the forigen keys than everything is fine.
I can't to understand clearly how to create strong and quickly application using EF. For example, I have class ForumPost (table ForumPost) for select one of record I write method like:
public ForumPost ForumPost(int ForumPostID) { return (from i in _dataContext.ForumPostSet where i.ForumPostID == ForumPostID select i).First(); }
all works. But on page (I use ASP.NET MVC) I should display info from another linked tables, ForumName (each post have ForumID) etc. So, I modify this method to:
public ForumPost ForumPost(int ForumPostID) { return (from i in _dataContext.ForumPostSet .Include("ChildPosts").Include("ParentPost").Include("Users").Include("Forums").Include("Tags").Include("ForumPostPolls") where i.ForumPostID == ForumPostID select i).First(); }
ok, all works. Then I want to make some actions in model with ForumPost, i.e.
public void RootPost(int PostID, ref Models.ForumPost Root) { ForumPost post = ForumPost(PostID); if (post.RootPost != null) { Root = ForumPost(post.RootPost.ForumPostID); } else Root = post; }
it works too. But problem is in speed. I not need in RootPost all those includes. So, I should to create one more method like:
private ForumPost ForumPostIncludes1(int ForumPostID) { return (from i in _dataContext.ForumPostSet .Include("ChildPosts") where i.ForumPostID == ForumPostID select i).First(); }
then ForumPostIncludes2, ForumPostIncludes3 etc... second way - redesign RootPost with LINQ expr, not with call another method. But in this way difficulties to change DB. third way? How to do it correctly?
i have to show organization chart for an organization. i have no idea how to do that,,how can i use system.graphics name space to show this chart can anybody help me with this..??data is basically coming from data base, the whole hierarchy is there in the database i have to show it graphically on organisation.aspx page.
1 - Is it necessary to have foreign key to obtain a Relation in Entity Framework between each entity.? 2 - I have a Language Table and many many table with a foreign key related to the language table. Is it right to add this foreign key or I should do something else ? Ex: Language LangID LangName
I have three table like above, table C is mapping table which has foreign key of Table A and B.How can i select and insert data in Table C using Entity Frame Work?
I'm trying to insert a new EF object containing a reference to a related table via foreign key, and cannot get the reference stored in the new object. I have two tables in a SQL Server 2008 Database:
Component Templates PartGroups
with a Foreign Key linking them thus: ComponentTemplates:ID [0..1<->*] PartGroups:ComponentTemplateID
I have imported these tables into a .NET web application project .edmx file (using a new ADO.NET Entity Data Model), and then created a Data Service which I then reference in a Silverlight 3.0 project. The objects are available as expected in the data context called by my Silverlight app and load correctly. Now, when I try to save a reference of ComponentTemplate into a newly created PartGroup, the PartGroup object is created in the database, but the value of ComponentTemplateID in the newly created table record is NULL.
[Code]....
(Note that _ctCtrl.ComponentTemplate is a confirmed non-NULL object reference to the parent object on which PartGroup is a child)
I set up Entity Framework for my Table and Stored Procedure to return data. Created a Domain Class as well.
In Domain Class, I am returning Objects as collection.
On .Aspnet page when I drop a Control(Combo,Dropdown) I can set up the source for the controls visually if the source is table.
However, In domain class I have stored precedure object that return collection of data And I cant not set up visually from Designer, I am only available to write code behind. is it possibble that i can set up from desingner.
I have a sql server database that includes the field ArticleID of type uniqueidentifier that is a primary key and is set to be auto-generated by the database when a new article is added.If i generate my entity model and do the following code:
[Code]....
Then a new article is saved to the database but the entity framework must be generating a new blank Guid and saving that to the database rather than allowing it to be auto generated as the articleid that shows up saved is all 0.How can i get the Entity Framework to let the Database generate the ArticleId?
Here I store the hierarchy data for the Organosation. Under_Level_ID denotes under which Level_ID the current Level is lying. e.g. for Branch the hierarchy in above table will be likeHO-->REGION-->Branch & for ZONE the hierarchy will be same as branch. Now my problem is I need all the hierarchy below a given Level. i.e. if am passing 132 as level then the SP should return me all the hierarchy elements lik Zone, Branch, fgfgfhf, Cluster,
when i create my entity data model i have a situation in the DB like this :
TableFirst : [Id,IdTableSecond,IdTableSecondAgain];TableSecond[Id] Created data model is: TableFirst.TableSecond and TableFirst.TableSecond1 Question is: Every time when i create my entity TableFirst.TableSecond will have same relation in behind (IdTableSecond) and TableFirst.TableSecond1 (IdTableSecondAgain) or they may change?
Is there a way to export a EF 4.0 Data Model to EF 3.5?
I looked around and found that we are not able to access EF 4.0 from a ASP.Net 3.5 project here: [URL]
Our project is the 1st to go to .Net 4.0 using Entity Framework and we (the team) were wondering if there was a way for the other projects that "might" need to access our data that are still using the .Net 3.5 framework.
i joined together more than one entity: Customer, Personel etc. i used inner join structures. if i look adonet entity framework ,5 entities are generated. i need to run this SP in C# side:
[Code]....
LOOK BELOW PİC : you can understand it :
MY C# codes: [Code]....
How can i get all joined data from sql with using randevu.GetRandevular(customerID
I have 3 tables User, role and UserInRole THe entity frame work made entities for User and Role and I have successfully made a join with the user and role entities using user.add(role); but I can't seem to get it to remove the link (I want to retain the user and role just remove their association).
using (ProviderEntities context = new ProviderEntities()) { User u = context.User .Where(n => n.ApplicationName == application) .Where(n => n.Username == username).First(); Roles r = context.Roles .Where(n => n.ApplicationName == application) .Where(n => n.RoleName == roleName) .First(); r.User.Remove(u); context.SaveChanges(); }
The oposite worked when I did r.User.Add(u); but it wont let me now remove it after it been created. Driving me mad as I can't see where I have gone wrong.
I have a stored procedure that generates a float value. I've added the stored procedure to my edmx file and created a function import, but the function isn't showing up in the object browser or via intellisense.
I'm using Visual Studio 2010 and I've verified that the stored procedure works in SSMS. Here is the current stored proc I'm using:
CarType Id - PK Name CarDetail Id - PK TypeId - FK to CarType
I have this simple example here and I want to insert a new CarDetail into the database but for some reason I cannot get the EntityKey to work in EF4 and Framework4 beta 2.
If i declare the following
car_detail.CarTypeReference.EntityKey = new System.Data.EntityKey("MyDB.CarType", "Id", 1)
Each time i try to call SaveChanges, it throws a INSERT constraint error saying that there is a conflict between CarType and CarDetail with the FK. It just seems like the hard coded 1 for CarType is NOT being passed through but instead the default value of 0. What is going on?
If i call car_detail.TypeId = 1 then it works fine with the INSERT.
I have created a .edmx for the northwind database. When I run the following statement, the correct number of detail records are retrieved and I can access the detail fields, but how do I access the order header record to view OrderDate, ShipAddress, etc...?
I'm using the linq to entity command to perform a record update. I want to set one of the fields back to NULL but I'm not sure how do it. I have a query such as
Dim record = From r in db.LISTS where r.ID = refID Select r record.Title = txtTitle.text if txtDetail.text = "" then record.Detail = end if
I am just getting started with entity framework with asp.net 3.5 using VS 2008
There are two tables, Categories & Subcategories:
Category table: CID, CategoryName Sub Category table: SID, CID, SubCategoryName I would like to get SID, CID, CategoryName, SubCategoryName in the gridview. Just as we write a select statement i.eSelect a.sid, b.cid, b.categoryname, b.subcategoryname from subcategories a inner join categories b on a.cid=b.cid & put the same in a gridview.
I was trying for the whole day & couldnt get atleast one url that would teach how to do it.
