DataSource Controls :: Is There A Way To Connect Two Entities Together In One New Entity
May 22, 2010And not doing a View that connect two tables ?Is there a way to connect two entities together in one new entity?
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DataSource Controls :: Best Way To Handle Inserts For Entities When Using FormViews And Entity Framework 4?
Mar 3, 2010I am trying to get some guidance with this issue:
I have a Customer object that has two address ID fields (one for HomeAddress and one for WorkAddress)
I am loading the Address Objects by using Include="HomeAddress, WorkAddress" and then binding to the properties using the Navigation Property on the Customer Entity
Can I use just one FormView for doing the Insert/Updates and binding it to an EntityDataSource or would I have to do all the Inserting/Updating manually?
Entity Framework 4 Merge Changes Between Two Entities?
Feb 8, 2011I use the ObjectDataSource in an ASP.NET Application.
Using the ASPxGridView. When Updating it goes back to the Data Access Layer and tries to update the Entity, now as I can see while having some properites (Columns, Visible = false) when the entity arrives in the update method the visible = false columns have no values.
I don't want to show all the columns...what if I need 3 of the 30 columns? So I thought I would get the original entity from the context and merge the differences from the updated entity.
Inheritance With POCO Entities In Entity Framework 4?
Mar 12, 2010I have a Consumer class and a BillableConsumer : Consumer class. When trying to do any operation on my "Consumers" set, I get the error message "Object mapping could not be found for Type with identity Models.BillableConsumer.
From the CSDL:
[code]....
Is this because I did not specifically add the BillableConsumer entity to the object set? How do I do that in a POCO scenario?
C# - Get Data From Entities That Inherit Others In Entity Framework 4.0?
Oct 19, 2010Due to the way the database was designed, in my model I have a User entity. The Contact entity inherits from the user entity, and the Profile entity inherits from the Contact entity.
How can I get a list of Profiles, and, how do I create a Profile?
Storing Entity Framework Self Tracking Entities In Session
Aug 13, 2010let us assume that I have a reusable business layer that further makes use of a data access layer that was implemented using Entity Framework 4.0. The entities returned/consumed by the business layer are self-tracking, allowing us all the goodies that come with those type of entities. I would like to be able to store the entities I work with across post backs (on order to avoid re-querying every time). Basically let us assume I have a paged GridView with 10 items in it, and something like a DetailsView to edit those items. Every time you select a new row on the grid, the details view updates with the information of the selected row. My preference would be to only query for the entities on the initial request of the page and store it in session. Then subsequently I have a list of entities that I can work with and eventually modify and send back to the business layer with all of the changes.
I really want to use session instead of view state to reduce the page payload (self tracking entities are heavy) however I really like view state for this because of the fact that when the user navigates away from the page there is no residual effect. Some of the things that worry me are: When a user navigates away from the page to another page, the entities from the previous page are still in session. I could always do something on load of a page to do housekeeping type of work. Not sure if that's good practice. I am worried about people opening browser tabs and having two views into the same page, it seems like that might pose a problem. Is this even a good approach? Seems like I am trying to have the best of all worlds, it would definitely be much easier to simply re-query on every post back for the entities and pay the 50-100ms hit of the database trip.
Entity Framework - Use Of Self-Tracking Entities In Across Multiple Posts
Dec 14, 2010I have a model that consists of Order, OrderLine, Product.
I want to create an Order and add OrderLines (each OrderLine related to a Product). I create the Order and add new OrderLines to it. Between posts I store the Order entity in Session (or ViewState). Just so you know I have added suppport for binary serialisation which works fine.
The relationship is therefore Order > OrderLine(s) > Product(s).
You might have already guessed what the problem is - that when I SaveChanges() I get the usual 'AcceptChanges cannot continue because the object's key values conflict with another object in the ObjectStateManager.' error.
I have referred to a number of articles online but none seem to handle this case (where I have the relationship across more than two entities) e.g. [URL].
This must be a very common requirement surely? Is there anyone out there doing the same kind of thing with Entity Framework (and without using DTOs etc)?
ADO.NET :: Entity Frame Work Make Use Of Linq To Entities?
Mar 6, 2011can we say like "Entity frame work make use of linq to entities"?
what is the relation between linq qnd entity frame work?
How To Avoid Clashes With Existing Entity ID's When Deserializing And Importing EF Entities
Feb 11, 2011I have an ASP.NET 4 web app that is using the Entity Framework to hold, amongst other things, a hierarchical structure of items that is used for features such as navigation.
One of the functions of the application allows the export of a particular branch of the hierarchy tree to XML, generated using a DataContractSerializer. Once exported, the intention is that the XML can then be uploaded to another instance of the same app, deserialized back into EF objects and then added to the data model on the second server.
When I try and import data in this way, I'm finding that I see the following error:
The object could not be added or attached because its EntityReference has an EntityKey property value that does not match the EntityKey for this object.
Taking a closer look at the XML that is generated by the serializer, I can see that the entity key is among the items that has been serialized. Since I'm importing entities that originate from a different database, some of the ID's clash.
What I'd ideally like to be able to do (unless I'm missing something here) is attach the imported entities to an object context and reset the ID's of the objects being imported.
Is there a smart way to do this? Do I simply have to set the ID for each of my imported entities to 0, attach them to the object context and then save changes?
DataSource Controls :: Add Entities Using EF?
Apr 20, 2010I have the following admx:
I have to add the (AccData, CntactData, PhnNumber, FnclDetail)entities to the database in one shot
What's the best practices to do the add operation for the above entities??
C# - Order A List Of Entities Based On A Field From A Separate Entity With A Relationship
Mar 6, 2011I'm using Entity Framework for my object-relational mapping, and jqGrid for my grid.
I have an Employee entity, that contains a ContactID field. I have a Contact entity that contains fields FirstName and LastName.
I want to display a list of Employees in a grid, and give the user the ability to sort by FirstName and LastName.
Here's what I have right now:
public JsonResult GridData(string sidx, string sord, int page, int rows)
{
var pageIndex = Convert.ToInt32(page) - 1;
var pageSize = rows;
var totalRecords = GetAllEmployees().Count();
var totalPages = (int)Math.Ceiling(totalRecords / (float)pageSize);
IQueryable<Employee> employees = GetAllEmployees().
OrderBy(sidx + " " + sord).
Skip(pageIndex * pageSize).
Take(pageSize).ToArray();
}
As you can see, this only gives me the ability to sort by fields in the Employee entity, so I can't sort by FirstName and LastName.
How can I modify this to accomplish that?
Entity Framework - Dynamic Data IS Showing Primary Keys For Every Table When Using Entities
Feb 4, 2010Using a very run-of-the-mill database, with identity int for primary keys, a Dynamic Data Entities Project (EntityFramework) displays the primary key for view and edit. When using Linq to Sql, the primary key fields are not displayed.
I would like to hide the primary keys and use Entity Framework (VS 2008, .Net 3.5 sp1).
DataSource Controls :: Generating Tables From Entities
May 13, 2010I'm creating entity on a project to use them as data on my website. I got my base simple entity Users and my DataContext. The thing is i would like the database to create the table as i create Entities.
I mean, actually my database doesn't have a Users table and do not generate it as i build and launch the project. I used to be a Java dev and in Java the table can be created with JPA so i guess Microsoft made it possible with ASP.net but how to do? I've looked on the web but didn't find it.
DataSource Controls :: Update Method Using SQL To Entities
Apr 14, 2010I'm having a question about an update method using SQL To Entities. I'm sending an object to the class and i'm updating him sucefully, but i need to specify each property of object instead of update in once. For example
[Code]....
In this case, i'm updating name, age and country sucefully but i want to use instead of update each property one-by-one, something like this:
[Code]....
So, the C = New should fill the C with all New values on properties, but this isn't work. To update an object, i've to update each property individual or can i update all in one like C = New?
DataSource Controls :: Inserting Related Entities?
Mar 5, 2010Inserting Related Entities?
View 14 RepliesC# - After Calling A Stored Procedure By Entity Framework, Tables Update In Database, But Entities Remain Same
Mar 15, 2011I created two stored procedures in SQL Server Management Studio.
First procedure add field in ProjcetsToUsers table (for many-to-many associations)
[code]....
I can delete the user from the project and then add another, and the new one is added but removed the remains.
As for data base both this function work correctly.
DataSource Controls :: Editing Data With Linq To Entities
May 21, 2010I'm trying to update data with the EF I can't seem to get the EntityKey when I debug and hit this line befor I save changes _entities.ApplyPropertyChanges entityToEdit.EntityKey .EntitySetName, blogEntryToEdit); The EntityKey is null dose anyone have any idea how this key is set can't SaveChanges() without it _entities.ApplyPropertyChanges(entityToEdit.EntityKey .EntitySetName, blogEntryToEdit);
View 6 RepliesDataSource Controls :: Can Get Two Tables In Only One Query With LINQ To Entities
May 20, 2010can get two tables in only one query with LINQ to Entities
Code for example:
[Code]....
DataSource Controls :: Perform A Search For Records In Linq-to-Entities?
Jan 26, 2010I trying to create a search mechanism for records in a EDM based on text entered on a text box in a web page.
For example, if I enter a partial name of a customer and/or state abrebiation for that customer on the Text Box (abc, TX)s, I want to search name and state fields in a Customer table in my database for matching customers.
I found a solution with the namespaceSystem.Linq.Dynamic, but for some reason it is not working. It does not expose the Search() method. Here is the code I am using to perform the search;
[Code]....
DataSource Controls :: Dynamic Linq To Entities...querying Date Fields?
Mar 9, 2010I am trying to use Linq to Entities with the Linq.Dynamic library (via Scott Guthrie) and I'm having some strange issues with querying dates.
[Code]....
This return no results, when it definitely should...
ADO.NET :: Add New Entity With Attributes And Connect
Dec 26, 2010is it possible to add a new entity with attributes and connect them and store details in the entity i am usign ms2010
View 1 RepliesDataSource Controls :: Linq To Entities - Multilevel Projection Into Business Class And Not Breaking Deferred Execution?
Mar 18, 2010I have a problem. (this a simplfied example)
In Entity framework I have a class which is effectively
fooEntity
{
public Guid Id {get; set;}
and a collection of fooChildEntity
}
a fooChildEntity is again an entityframework class
fooChildEntity
{
public Guid kidId {get; set;}
}
Now I also have a pair of business layer classes foo and fooChild
foo
{
public Guid Id {get; set;}
ilist<fooChild> Children {get;set;}
}
fooChild
{
public Guid kidId {get; set;}
}
My aim is to write a linq to entites that will allow me to convert the entity foo and children into the business foo and children without breaking deferred execution ( I will be adding filters to reduce the recordset at a higher coding level in the business layer)
doing something like
this.context.fooEntity
.include(fooChildEntity)
.Select( fe => new foo { Id=fe.Id ,
fe.foreach(fec => Children.add( new fooChild { kidId = fec.kidId}))})
.AsIQueryable()
is plainly rubbish and would never compile - it is however an indication of the direction I was thinking .
Even if I got a foreach to work like that or similar it would break deferred execution
At this point there are around 300,000 foo entities which I will eventualy filter to 5 or 6 foo's - this is why deferred execution is needed.
C# - LLBLGen Pro V2.6 Designer / How To Delete More Than One Entity At The Same Time In The Designer Entities List
May 10, 2010How do you delete more than one entity at the same time in the designer Entities list. it seems that the designer interface only allows the selection of 1 entity at a time....
View 1 RepliesEntity Framework - Connect Data Access Methods To UI?
Mar 2, 2010I am seriously at a loss here. The three things that will not change in this project are the fact that we are using the Entity Framework to do our data access, the fact that we want thorough unit testing and that our UI is asp.net. My question is how the hell do you make this work in Asp.net? E.g. You can use an ObjectDataSource to connect a method to a control, but if this control is a FormView you have all these problems [URL] to deal with and it simply doesn't work.
Furthermore, with grids, you don't get paging or sorting out of the box unless you use an EntityDataSource which basically circumvents your entire application. I can't be the only person who cries at this. What do you do?
Using Entity Framework To Connect To Multiple Similar Tables In MVC?
Jun 10, 2010A relative newcomer to .net MVC2 and the entity framework, I am working on a project which requires a single web application, (C# .net 4), to connect to multiple different databases depending on the route of access, (ie subdomain).
No problem with this in principle and all the logic is written to transform the subdomain into an entity connection and pass this through to the Entity Model.
The problem comes with the fact that the different database whilst being largely similar in structure contain 3 or 4 unique tables bespoke to that instance.
To my mind there are two ways to solve this issue, neither of which i am sure will be possible.
1/ Use a separate entity model for each database. -Attempts down this route have through up conflicts where table/sp names are the same across differnt db's, or implicit conversion errors when I try and put the different models in different namespaces. or
2/ Overwrite the classes which refer to the changeable database objects based on the value of a base controller property.
My question is if either of theser routes can ever work in principle or if i should just give up on the EF and connect to the dtabases directlky using ADO. Perhaps there is another way to solve this problem i haven't thought of?
