Im trying to perform update of some records.
When im calling a create action after i insert the record i take out some of the records and change a non-primary key value. Then i call UpdateModel on each to try to save them.
But i get error: The model of type "" was not successfully updated.
If i check ModelState i see that the id value (wich is PK and IDENTITY fails -> A value is required.). The value at id isnt there.
What am i doing wrong?
Hard to guess what the reason might be, but if you trigger the whole thing from a form, I would do "view source" of the html form and make sure your id is there (in a hidden field?). Maybe you forgot to set the id property in your viewmodel before passing it to the view?
That's my best guess without seeing some sample code :)
Related
I'm using Entity Framework (DbContext with database first) with MVC. When user save from a form, I have a condition in the controller that send the entity to the update of insert method depending of some internal flag of mine.
When sending entity to the update method, I flag it to modified using context.Entry(myEntity).State = EntityState.Modified;, I call saveChanges() and everything work well.
When sending the entity to the insert method, I flag it to added using context.Entry(myEntity).State = EntityState.Added; but when calling saveChanges() I receive error about 2 fields that are required...
The problem is that thoses 2 fields are not empty and they effectively contain valid data just before saving... I have even try to force new values to thoses 2 fields just before saving but same error.
It may be usefull to mention that I'm using Devart DotConnect For PostgreSQL as db provider.
Any idea how to debug this problem?
EDIT:
Here is the error:
Validation failed for one or more entities. See 'EntityValidationErrors' property for more details.
When looking for this EntityValidationErrors I receive the 2 following specific errors:
The flg_actif field is required
The user_creation field is required
As mentionned before, those fields are filled with data just before saving so I don't understand what is happening.
I'm using EF v4.0.30319 (system.data.entity=> v4.0 and EntityFramework=> v4.4)
EDIT2:
Just to clarify a little bit more: The entity I'm trying to insert already exist in database. The form show the data of this database row. When saving, I decide if I update the row (this work well) but sometime, I need to insert the edited row as a new register instead of updating it to keep an history of the change in database.
Could you verify if the EntityKey property is set or null on the items you are trying to save?
If it already has a key, the context is already aware of the item, and you should use Attach instead of setting the state to added manually.
EDIT: To summarise the point from below. It looks like what you are doing is inserting a new copy of a row already associated with a context. That is almost certainly your problem. Try creating a fresh object based on your original row (i.e. copy the variable values or use a copy constructor), then add that new object.
Additionally, you should not need to set the state manually on a newly added object. You are trying to force the state here because the context doesn't see that item as a new one.
I have a Client entity and PostCode entity in Linq to SQL model. The Clients table in database contains client_postcode column which is a FK column to postalcode column in PostCode table, which is a varchar column primary key for PostCode table.
When updating Client, in my code I do this
// postcode
updating.PostCode = (from p in ctx.PostCodes
where p.postalcode.Equals(client.PostCode.postalcode)
select p).First();
where client object is provided from ASP.NET MVC View form. This code seems to set the PostCode related entity fine. But when calling SubmitChanges() I receive the following exception:
Value of member 'postalcode' of an object of type 'PostCode' changed. A member defining the identity of the object cannot be changed. Consider adding a new object with new identity and deleting the existing one instead.
So I am currently unable to change the related entity. How is that done in Linq to Sql?
UPDATE:
After further review and troubleshooting I found out that the problem is in ASP.NET MVC UpdateModel() call. If I call UpdateModel() to update the existing entity with the edited data, something is wrong with the FK assignement for PostCode. If I don't call UpdateModel and do it by hand, it works.
Any ideas what goes wrong in UpdateModel() that it can't set the relationship to foreign key entities correctly?
I am updating this question and starting a bounty. The question is simplified. How to successfully use L2S and UpdateModel() to work when updating items (with related entities as FK) in ASP.NET MVC Edit views?
It seems to me that you are receiving PostCode.postalcode in the http post request.
Based on how model binding works, the UpdateModel call updates .PostCode.postalcode of the model you are passing to it.
Use this overload to include or exclude specific properties.
Wouldn't updating.client_postcode = client.client_postcode; accomplish what you want?
Client.PostCode should be looked up on seek based on client_postocde.
You can not do what you are trying, you cannot change the Postcode like that.
James' idea is in the right direction.
Updatemodel() takes the matching values from the Formcollection
How do these values come in the Formcollection? What are their keys?
basically there are 2 ways in editing an object.
option 1:
all the value names you want to update have corresponding keys in the Formcollection, which leaves you just to call UpdateModel() of the original object. do SubmitChanges()
option 2:
Get the original object, change it's values manually (because the keys dont correspond) and do SubmitChanges()
you are tying to change a link, you cant do that. you can only edit the updating.client_postcode which in this case is a string?
Can you please copy the whole action here? So I can write some code for you without gambling.
I'm working on my first ASP.NET MVC (beta for version 3) application (using EF4) and I'm struggling a bit with some of the conventions around saving a new record and updating an existing one. I am using the standard route mapping.
When the user goes to the page /session/Evaluate they can enter a new record and save it. I have an action defined like this:
[ActionName("Evaluate")]
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult EvaluateSave(EvaluteSessionViewModel evaluatedSession)
{
}
When they save I grab an entity off the view model and attach it to my context and save. So far, so good. Now I want the user to be able to edit this record via the url /session/Evaluate/1 where '1' is the record ID.
Edit: I have my EF entity attached as a property to the View Model.
If I add an overloaded method, like this (so I can retrieve the '1' portion automatically).
[ActionName("Evaluate")]
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult EvaluateSave(ID, EvaluteSessionViewModel evaluatedSession)
{
}
I get an "The current request for action 'Evaluate' on controller type 'SessionsController' is ambiguous between the following action" error. I'm not sure why they're ambiguous since they look unique to me.
I decided that I was just going to skip over this issue for now and see if I could get it to update an existing record, so I commented out the EvaluateSave that didn't have the ID parameter.
What I'd like to do is this:
// Load the original entity from EF
// Rebind the postback so that the values posted update the entity
// Save the result
Since the entity is populated as the parameter (evaluatedSession) the rebinding is happening too soon. But as I look at the approach I'd like to take I realized that it opens my code up to hacking (since a user could add in fields into the posted back page and these could override the values I set in the entity).
So it seems I'm left with having to manually check each field to see if it has changed and if it has, update it. Something like this:
if (evaluatedSession.MyEntity.myField <> savedSession.myField)
savedSession.myField = evaluatedSession.MyEntity.myField;
Or, save a copy of the entity and make sure none of the non-user editable ones have changed. Yuck.
So two questions:
First: how do I disambiguate the overloaded methods?
Second: is there a better way of handling updating a previously saved record?
Edit: I guess I could use something like Automapper...
Edit 9/22/2010 - OK, it looks like this is supposed to work with a combination of two items: you can control what fields bind (and specifically exclude some of them) via the [Bind(Exclude="field1,field2")] attribute either on the class level or as part of the method doing the saving, ex.
public ActionResult EvaluateSave([Bind(Exclude="field1")] EvaluateSessionViewModel evaluatedSession)
From the EF side of things you are supposed to be able to use the ApplyCurrentValues() method from the context, ex.
context.ApplyCurrentValues(savedEval.EntityKey.EntitySetName, evaluatedSession);
Of course, that doesn't appear to work for me. I keep getting "An object with a key that matches the key of the supplied object could not be found in the ObjectStateManager. Verify that the key values of the supplied object match the key values of the object to which changes must be applied.".
I tried attaching the original entity that I had just loaded, just in case it wasn't attached to the context for some reason (before ApplyCurrentValues):
context.AttachTo(savedEval.EntityKey.EntitySetName, savedEval);
It still fails. I'm guessing it has something to do with the type of EF entity object MVC creates (perhaps it's not filled in enough for EF4 to do anything with it?). I had hoped to enable .NET framework stepping to walk through it to see what it was attempting to do, but it appears EF4 isn't part of the deal. I looked at it with Reflector but it's a little hard for me to visualize what is happening.
Well, the way it works is you can only have one method name per httpverb. So the easiest way is to create a new action name. Something like "Create" for new records and "Edit" for existing records.
You can use the AntiForgeryToken ( http://msdn.microsoft.com/en-us/library/dd492767.aspx ) to validate the data. It doesn't stop all attempts at hacking but it's an added benefit.
Additional
The reason you can only have one action name per httpverb is because the model binders only attempt to model bind and really aren't type specific. If you had two methods with the same action name and two different types of parameters it can't just try and find the best match because your intent might be clearly one thing while the program only sees some sort of best match. For instance, your might have a parameter Id and a model that contains a property Id and it might not know which one you intend to use.
PLEASE NOTE: I've answered my own question with a link to an answer to a similar question. I'll accept that answer once I'm allowed to (unless anyone comes up with a better answer meantime).
I have a database column defined as NVARCHAR(1000) NOT NULL DEFAULT(N'') - in other words, a non-nullable text column with a default value of blank.
I have a model class generated by the Linq-to-SQL Classes designer, which correctly identifies the property as not nullable.
I have a TextAreaFor in my view for that property. I'm using UpdateModel in my controller to fetch the value from the form and populate the model object.
If I view the web page and leave the text area blank, UpdateModel insists on setting the property to NULL instead of empty string. (Even if I set the value to blank in code prior to calling UpdateModel, it still overwrites that with NULL). Which, of course, causes the subsequent database update to fail.
I could check all such properties for NULL after calling UpdateModel, but that seems ridiculous - surely there must be a better way?
Please don't tell me I need a custom model binder for such a simple scenario...!
Might be duplicate or something in the line of this:
MVC binding form data problem
I fear custom model binder will be necessary. ;)
You might want to use a partial class implementation of your entity that implements the on property changed handler for that particular property. When you detect that the property has been changed to NULL, simply change it to string.Empty. That way anytime NULL is assigned to the property it gets reset to the empty string.
I encounter an error of the form: "The model item passed into the dictionary is of type FooViewData but this dictionary requires a model item of type bar" even though I am passing in an object of the correct type (bar) for the typed user control.
What #MattMitchell said is probably the reason you're seeing this error.
If you want to know why; it is because when you pass null as the controlData parameter when using RenderUserControl(), the framework will try to pass the view data from the current view context onto the user control instead (see UserControlExtensions.DoRendering method in System.Web.Mvc).
What has probably happened is that the object provided when rendering the user control is actually null.