EntityFramework update entity with related objects - c#

I have a Project entity and a Rule entity. A project can have many rules.
Edit 1: Here is the relation we have defined. Sorry for not using plural in the navigation property, we haven't updated it yet.
So I have this method:
public bool Update(Project project)
{
Logger.Log(GetType(), string.Format("Updating project {0}", project));
using (var ctx = new EntityModelContainer())
{
if (project.Id == 0)
{
return false;
}
try
{
ctx.ProjectSet.Attach(project);
ctx.Entry(project).State = EntityState.Modified;
return ctx.SaveChanges() >= 1;
}
catch (Exception exc)
{
throw new ComplianceException(exc.Message, exc);
}
}
}
It will update all scalar attributes of a project. But if I add or delete a rule to a project and run Update(project), it is not considered. Why?
Edit 2: I have also tried to re-read the project and assign the updated values. Please notice that projectRead.Rule is a list.
public bool Update(Project projectGiven)
{
// Add all changes here
Project projectRead = this.ReadProject(projectGiven.Id);
if (projectRead == null)
{
Logger.Log(GetType(), "Project not found");
return false;
}
projectRead.ProjectName = projectRead.ProjectName;
projectRead.Report = projectRead.Report;
projectRead.Rule = projectRead.Rule;
Logger.Log(GetType(), string.Format("Updating project {0}", projectRead));
using (var ctx = new EntityModelContainer())
{
...
Thank you very much!

Seems to me that with latest version of entity framework, and entity is not added automatically to the change tracker if assigned to and entity that is already in the change tracker.
Obviously this depends on the way role and project are related.
I suppose the more simple way si to create a procedure that reload the project including all the roles, delete the selected one from the list, and after to save it, at this point I think al the updates are done correrctly.

I solved the problem. I need to reload the project within the same context before I update.

Related

linq to update value in database view

I am working as a selenium automation tester. I tried adding the table to datamodel in visual 2013, since the table has hierarchy, it has thrown error. So, I found a work around to use view. Now I need to update a value in view using sql. I used
var acct = context.Regression_TestAccounts.Where(f => f.Account_ID.Equals(acctId))
.FirstOrDefault();
acct.AvailableDailyCreditLimit_Amt = acct.ApprovedDailyCreditLimit_Amt;
acct.AvailableTotalCreditLimit_Amt = acct.ApprovedTotalCreditLimit_Amt;
This is not making any changes to the values.Could some one help me with this.
Well, there is a lot of code that you are missing. This is not a Selenium issue. It's an "I don't know Entity Framework" issue. First, you have to call SaveChanges() to be able to persist any updates in your objects. Also, it is recommended to use Transactions so you can revert any possible problems during your update. Also, here is an article on how to add/attach entity states. This way you can update the object.
public void Update(int acctId)
{
using(var context = new Context())
{
using(var dbContextTransaction = new context.Database.BeginTransaction())
{
try
{
//improved query
var acct = context.Regression_TestAccounts
.FirstOrDefault(f => f.Account_ID == acctId);
if(acct == null) //don't just return, tell the user there was no update
return;
acct.AvailableDailyCreditLimit_Amt = acct.ApprovedDailyCreditLimit_Amt;
acct.AvailableTotalCreditLimit_Amt = acct.ApprovedTotalCreditLimit_Amt;
context.Entry(acct).State = acct.Account_ID == 0
? EntityState.Added
: EntityState.Modified;
context.SaveChanges();
dbContextTransaction.Commit();
}
catch (Exception ex)
{
dbContextTransaction.Rollback();
throw;
}
}
}
}

Attaching an entity of type failed because another entity of the same type already has the same primary key value

Error message: Attaching an entity of type failed because another entity of the same type already has the same primary key value.
Question: How do I attached an entity in a similar fashion as demonstrated in the AttachActivity method in the code below?
I have to assume the "another entity" part of the error message above refers to an object that exists in memory but is out of scope (??). I note this because the Local property of the DBSet for the entity type I am trying to attach returns zero.
I am reasonably confident the entities do not exist in the context because I step through the code and watch the context as it is created. The entities are added in the few lines immediately following creation of the dbcontext.
Am testing for attached entities as specified here:what is the most reasonable way to find out if entity is attached to dbContext or not?
When looking at locals in the locals window of visual studio I see no entities of type Activity (regardless of ID) except the one I am trying to attach.
The code executes in this order: Try -> ModifyProject -> AttachActivity
Code fails in the AttachActivity at the commented line.
Note the code between the debug comments which will throw if any entities have been added to the context.
private string AttachActivity(Activity activity)
{
string errorMsg = ValidateActivity(activity); // has no code yet. No. It does not query db.
if(String.IsNullOrEmpty(errorMsg))
{
// debug
var state = db.Entry(activity).State; // Detached
int activityCount = db.Activities.Local.Count;
int projectCount = db.Activities.Local.Count;
if (activityCount > 0 || projectCount > 0)
throw new Exception("objects exist in dbcontext");
// end debug
if (activity.ID == 0)
db.Activities.Add(activity);
else
{
db.Activities.Attach(activity); // throws here
db.Entry(activity).State = System.Data.Entity.EntityState.Modified;
}
}
return errorMsg;
}
public int ModifyProject(Presentation.PresProject presProject, out int id, out string errorMsg)
{
// snip
foreach (PresActivity presActivity in presProject.Activities)
{
Activity a = presActivity.ToActivity(); // returns new Activity object
errorMsg = ValidateActivity(a); // has no code yet. No. It does not query db.
if (String.IsNullOrEmpty(errorMsg))
{
a.Project = project;
project.Activities.Add(a);
AttachActivity(a);
}
else
break;
}
if (string.IsNullOrEmpty(errorMsg))
{
if (project.ID == 0)
db.Projects.Add(project);
else
db.AttachAsModfied(project);
saveCount = db.SaveChanges();
id = project.ID;
}
return saveCount;
}
This is the class that news up the dbContext:
public void Try(Action<IServices> work)
{
using(IServices client = GetClient()) // dbContext is newd up here
{
try
{
work(client); // ModifyProject is called here
HangUp(client, false);
}
catch (CommunicationException e)
{
HangUp(client, true);
}
catch (TimeoutException e)
{
HangUp(client, true);
}
catch (Exception e)
{
HangUp(client, true);
throw;
}
}
I am not asking: How do I use AsNoTracking What difference does .AsNoTracking() make?
One solution to avoid receiving this error is using Find method. before attaching entity, query DbContext for desired entity, if entity exists in memory you get local entity otherwise entity will be retrieved from database.
private void AttachActivity(Activity activity)
{
var activityInDb = db.Activities.Find(activity.Id);
// Activity does not exist in database and it's new one
if(activityInDb == null)
{
db.Activities.Add(activity);
return;
}
// Activity already exist in database and modify it
db.Entry(activityInDb).CurrentValues.SetValues(activity);
db.Entry(activityInDb ).State = EntityState.Modified;
}
Attaching an entity of type failed because another entity of the same type already has the same primary key value. This can happen when using the Attach method or setting the state of an entity to Unchanged or Modified if any entities in the graph have conflicting key values. This may be because some entities are new and have not yet received database-generated key values. In this case use the Add.
The solution is that
if you had to use GetAll()
public virtual IEnumerable<T> GetAll()
{
return dbSet.ToList();
}
Change To
public virtual IEnumerable<T> GetAll()
{
return dbSet.AsNoTracking().ToList();
}
I resolved this error by changing Update method like below.
if you are using generic repository and Entity
_dbContext.Set<T>().AddOrUpdate(entityToBeUpdatedWithId);
or normal(non-generic) repository and entity , then
_dbContext.Set<TaskEntity>().AddOrUpdate(entityToBeUpdatedWithId);
If you use AddOrUpdate() method, please make sure you have added
System.Data.Entity.Migrations namespace.

Add or Update a Record?

I have an MVC application with the following code in the POST method of the controller. I am doing an EF Add and obviously that is not right. I want it to add the record if it doesn't exist, otherwise Update. How can I do that please?
try
{
AttributeEntities db = new AttributeEntities();
IEnumerable<string> items = viewModel.SelectedAttributes2;
int i = 0;
foreach (var item in items)
{
var temp = item;
// Save it
SelectedHarmonyAttribute attribute = new SelectedHarmonyAttribute();
attribute.CustomLabel = viewModel.ItemCaptionText;
attribute.IsVisible = viewModel.Isselected;
string harmonyAttributeID = item.Substring(1, 1);
// attribute.OrderNumber = Convert.ToInt32(order);
attribute.OrderNumber = i++;
attribute.HarmonyAttribute_ID = Convert.ToInt32(harmonyAttributeID);
db.SelectedHarmonyAttributes.Add(attribute);
db.SaveChanges();
}
}
You would need to check the database for the record you are trying to add/update. If the look-up returns null, that means that it doesn't exist in the database. If it does, you can modify the record that you looked up and call db.SaveChanges() to persist the changes you made to the database.
Edit:
int id = Convert.ToInt32(harmonyAttributeID);
var existingEntry = db.SelectedHarmonyAttributes.SingleOrDefault(x => x.HarmonyAttribute_ID == id);
One common way to determine an add or update is by simply looking at an identifier field, and setting the appropriate state.
using System.Data;
SelectedHarmonyAttribute attribute;
using (var db = new YourDbContext())
{
db.Entry(attribute).State = attribute.HarmonyAttribute_ID == 0 ? EntityState.Added : EntityState.Modified;
db.SaveChanges();
}
You could import the System.Data.Entity.Migrations namespace and use the AddOrUpdate extension method:
db.SelectedHarmonyAttributes.AddOrUpdate(attribute);
db.SaveChanges();
EDIT:
I'm assuming that SelectedHarmonyAttributes is of type DbSet
EDIT2:
Only drawback with doing it this way (and it may not be a concern for you), is that your entity isn't responsible for it's own state change. This means that you can update any property of the entity to something invalid, where you might want to internally validate it on the entity itself or maybe do some other processing you always want to occur on update. If these things are a concern for you, you should add a public Update method onto the entity and check for its existence on the database first. e.g:
var attribute = db.SelectedHarmonyAttributes.SingleOrDefault(x => x.HarmonyAttribute_ID == harmonyAttributeID);
if (attribute != null)
{
attribute.Update(viewModel.ItemCaptionText, viewModel.Isselected, i++);
}
else
{
attribute = new Attribute(viewModel.ItemCaptionText, viewModel.Isselected);
db.SelectedHarmonyAttributes.Add(attribute);
}
db.SaveChanges();
Your update method might look something like:
public void Update(string customLabel, bool isVisible, int orderNumber)
{
if (!MyValidationMethod())
{
throw new MyCustomException();
}
CustomLabel = customLabel;
IsVisible = isVisible;
OrderNumber = orderNumber;
PerformMyAdditionalProcessingThatIAlwaysWantToHappen();
}
Then make all of the entities' properties public "get" but protected "set" so they can't be updated from outside the entity itself. This might be going off an a bit of a tangent but using the AddOrUpdate method would assume you don't want to control the way an update occurs and protect your domain entity from getting into an invalid state etc. Hope this helps!

Update database via Linq to SQL not working

I'm developing a C# ASP.NET application, in which i'm retrieving some data from the database, throwing in a form, and when i click on Save, i want it to save my changes in the database.
I'm using Linq to SQL. The code below, at the end, call the method ClienteBusiness.SalvarAlteracoes(cliente), which by the way, only calls the ClienteData.SalvarAlteracoes(cliente) method.
protected void Salvar()
{
TB_CLIENTE_CLI cliente = new TB_CLIENTE_CLI();
int idEstado = 0;
int idCidade = 0;
if (!Int32.TryParse(ddlEstado.SelectedValue, out idEstado))
{
return;
}
if (!Int32.TryParse(Request.Form[ddlCidade.UniqueID], out idCidade))
{
return;
}
cliente.TXT_RAZAOSOCIAL_CLI = txtRazaoSocial.Text;
cliente.TXT_NOMEFANTASIA_CLI = txtNomeFantasia.Text;
cliente.TXT_CNPJ_CLI = txtCNPJ.Text;
cliente.TXT_CEP_CLI = txtCEP.Text;
/*e os demais campos*/
//Se a tela for de edição, altera o valor do ID para o cliente correspondente.
cliente.ID_CLIENTE_CLI = this.IdCliente;
ClienteBusiness.SalvarAlteracoes(cliente);
HTMLHelper.jsAlertAndRedirect(this, "Salvo com sucesso!", ResolveUrl("~/Pages/ClientePage.aspx"));
}
The method which save the changes is described below:
public static Int32 SalvarAlteracoes(TB_CLIENTE_CLI cliente)
{
using (PlanoTesteDataContext context = DataContext.ObterConexao())
{
if (cliente.ID_CLIENTE_CLI == 0)
{
context.TB_CLIENTE_CLIs.InsertOnSubmit(cliente);
}
else
{
context.TB_CLIENTE_CLIs.Attach(cliente, true);
}
context.SubmitChanges();
} return cliente.ID_CLIENTE_CLI;
}
On the line context.TB_CLIENTE_CLIs.Attach(cliente, true); i'm receiving a System.InvalidOperationException: An entity can only be attached as modified without original state if it declares a version member or does not have an update check policy.
I've already checked the UpdateChecks and they are set to Never.
What can I do? Thanks and sorry for the bad english.
This should work:
else
{
context.Refresh(System.Data.Linq.RefreshMode.KeepCurrentValues, cliente);
context.TB_CLIENTE_CLIs.Attach(cliente);
}
This Refresh overload will keep the changes made by the user,it compares the modified entity with the original values from the database, detects the difference and marks the entity as modified and the call to SubmitChanges applies the update to the database.
You may very well run into trouble using Linq2SQL with disconnected entities. EF is a more suited solution to handle this.
However, please ensure you have set all properties on the entity on UpdateCheck to NEVER. I have tested this myself and it works. If this does work it will run an UPDATE statement on every column regardless of whether it has been updated or not. Could cause a problem if you use triggers on your tables. It might be a better idea to use a Timestamp instead to track the entities so concurrency issues between multiple users can be raised.
If you try to Attach an entity from a context where the ObjectTrackingEnabled is not set to False then you will have the following exception thrown:
An unhandled exception of type 'System.NotSupportedException' occurred in System.Data.Linq.dll
Additional information: An attempt has been made to Attach or Add an entity that is not new, perhaps having been loaded from another DataContext. This is not supported.
As an example please use the following for retrieving and reattaching an entity:
public TB_CLIENTE_CLI Get(int id)
{
using (PlanoTesteDataContext ctx = new PlanoTesteDataContext())
{
ctx.ObjectTrackingEnabled = false;
return ctx.TB_CLIENTE_CLI.SingleOrDefault(n => n.ID == id);
}
}
public void Save(TB_CLIENTE_CLI cliente)
{
using (PlanoTesteDataContext ctx = new PlanoTesteDataContext())
{
ctx.DeferredLoadingEnabled = false;
ctx.TB_CLIENTE_CLI.Attach(cliente, true);
ctx.SubmitChanges();
}
}
You will also need to set DeferredLoadingEnabled loading to False in the Save method so that you can save down changes on the entity subsequent times after the first initial save on modification.

Enity Framework updating with a child table causing errors

I have the following update function
public void UpdateBatchDefinition(BatchDefinition batchToUpdate)
{
if (batchToUpdate == null)
{
throw new ArgumentNullException("batchToUpdate");
}
BatchDefinition foundDefinition =
this.context.BatchDefinitions.SingleOrDefault(definition => definition.Id == batchToUpdate.Id);
if (foundDefinition != null)
{
if (!string.IsNullOrWhiteSpace(batchToUpdate.Name))
{
foundDefinition.Name = batchToUpdate.Name;
}
if (!string.IsNullOrWhiteSpace(batchToUpdate.Description))
{
foundDefinition.Description = batchToUpdate.Description;
}
if (!string.IsNullOrWhiteSpace(batchToUpdate.LoadType))
{
foundDefinition.LoadType = batchToUpdate.LoadType;
}
if (batchToUpdate.JobId != Guid.Empty)
{
foundDefinition.JobId = batchToUpdate.JobId;
}
foundDefinition.Tables = batchToUpdate.Tables;
this.context.SaveChanges();
}
}
the issue I am having Is when I am trying to update the Tables list. Tables is a List of Table and Table is a Entity of another table
Tables could be added to, removed from or left alone. I need to update that with what ever is being passed in
when I run this right now I get an 'EntityValidationErrors' error, though it wont tell me what the validation issue actually is.
on Inserting I got the same error but was able to fix it using the following
var underlyingContext = this.context as DbContext;
if (underlyingContext != null)
{
foreach (var table in batchDefinition.Tables)
{
// Need to mark the table entity as unchanged or
// else EF will treat it as a new table
underlyingContext.Entry(table).State = EntityState.Unchanged;
}
}
so I tried using that in this update function
var underlyingContext = this.context as DbContext;
if (underlyingContext != null)
{
foreach (var table in foundDefinition.Tables)
{
// Need to mark the table entity as unchanged or
//else EF will treat it as a new table
underlyingContext.Entry(table).State = EntityState.Unchanged;
}
}
foundDefinition.Tables = batchToUpdate.Tables;
and I get the following error instead:
AcceptChanges cannot continue because the object's key values conflict
with another object in the ObjectStateManager. Make sure that the key
values are unique before calling AcceptChanges.
Any thoughts one what I am missing here?
Change end of your update method like this:
foreach (var t in foundDefinition.Tables.ToList())
Context.Tables.Remove(t);
foundDefinition.Tables = batchToUpdate.Tables;
this.context.SaveChanges();
And about your last error, it is said that there are some duplicates in your context. So, EF can't save the context changes into the db (because there are duplicates in the context!)
In fact, I don't know the last error is from add or delete - you didn't mention clearly. So, I don't know the last two code samples are from your add method, or your update method...
However for update, the trick I mentioned here, must solve your problem for update...

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