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ASP.NET C#: Entity updating is being blocked

Experiencing an issue about updating mysql DB through EF. It's not the first time I'm dealing with it, so I had some ideas about why isn't my data getting changed. I tried changing an element in goods array; tried editing an object, recieved through LINQ-request (seen some examples of this method); made some attempts on marking element found in the database before editing (like EntityState and Attach()). Nothing of these made any difference, so I tried removing <asp:UpdatePanel> from Site.Master to see what happens (responsive for postback blocking to prevent page shaking on update), but nothing changed (while btnRedeemEdit.IsPostBack having its default value).
Code below is the function I use for updates.
protected void btnRedeemEdit_Click(object sender, EventArgs e)
{
if (!string.IsNullOrEmpty(Request.QueryString["id"]))
{
var db = new GoodContext();
var goods = db.Goods.ToList();
Good theGood = goods.FirstOrDefault(x => x.Id == int.Parse(Request.QueryString["id"]));
//db.Goods.Attach(theGood);//No effect
//db.Entry(theGood).State = System.Data.Entity.EntityState.Modified; //No effect
if (theGood != default)
{
theGood.AmountSold = GetInput().AmountSold;
theGood.APF = GetInput().APF;
theGood.Barcode = GetInput().Barcode;
theGood.Description = GetInput().Description;
theGood.ImagesUrl = GetInput().ImagesUrl;//"https://i.pinimg.com/564x/2d/b7/d8/2db7d8c53b818ce838ad8bf6a4768c71.jpg";
theGood.Name = GetInput().Name;
theGood.OrderPrice = GetInput().OrderPrice;
theGood.Profit = GetInput().Profit;
theGood.RecievedOn = GetInput().RecievedOn;//DateTime.Parse(GetInput().RecievedOn).Date.ToString();
theGood.TotalAmount = GetInput().TotalAmount;
theGood.WeightKg = GetInput().WeightKg;
//SetGoodValues(goods[editIndex],GetInput());//Non-working
db.SaveChanges();
Response.Redirect("/AdminGoods");
}
else Response.Write($"<script>alert('Good on ID does not exist');</script>");
}
else Response.Write($"<script>alert('Unable to change: element selected does not exist');</script>");
}
Notice, that no alerts appear during execution, so object in database can be found.
Are there any more things, that can be responsible for blocking database updates?

A few things to update & check:
Firstly, DbContexts should always be disposed, so in your case wrap the DbContext inside a using statement:
using (var db = new GoodContext())
{
// ...
}
Next, there is no need to load all goods from the DbContext, just use Linq to retrieve the one you want to update:
using (var db = new GoodContext())
{
Good theGood = db.Goods.SingleOrDefault(x => x.Id == int.Parse(Request.QueryString["id"]));
if (theGood is null)
{
Response.Write($"<script>alert('Good on ID does not exist');</script>");
return;
}
}
The plausible suspect is what does "GetInput()" actually do, and have you confirmed that it actually has the changes you want? If GetInput is a method that returns an object containing your changes then it only needs to be called once rather than each time you set a property:
(Inside the using() {} scope...)
var input = GetInput();
theGood.AmountSold = input.AmountSold;
theGood.APF = input.APF;
theGood.Barcode = input.Barcode;
theGood.Description = input.Description;
// ...
db.SaveChanges();
If input has updated values but after calling SaveChanges you aren't seeing updated values in the database then there are two things to check.
1) Check that the database connection string at runtime matches the database that you are checking against. The easiest way to do that is to get the connection string from the DbContext instance's Database.
EF 6:
using (var db = new GoodContext())
{
var connectionString = db.Database.Connection.ConnectionString; // Breakpoint here and inspect.
EF Core: (5/6)
using (var db = new GoodContext())
{
var connectionString = db.Database.GetConnectionString();
Often at runtime the DbContext will be initialized with a connection string from a web.config / .exe.config file that you don't expect so you're checking one database expecting changes while the application is using a different database / server. (More common than you'd expect:)
2) Check that you aren't disabling tracking proxies. By default EF will enable change tracking which is how it knows if/when data has changed for SaveChanges to generate SQL statements. Sometimes developers will encounter performance issues and start looking for ways to speed up EF including disabling change tracking on the DbContext. (A fine option for read-only systems, but a pain for read-write)
EF6 & EF Core: (DbContext initialization)
Configuration.AutoDetectChangesEnabled = false; // If you have this set to false consider removing it.
If you must disable change tracking then you have to explicitly set the EntityState of the entity to Modified before calling SaveChanges():
db.Entry(theGood).State = EntityState.Modified;
db.SaveChanges();
Using change tracking is preferable to using EntityState because with change tracking EF will only generate an UPDATE statement if any values have changed, and only for the values that changed. With EntityState.Modified EF will always generate an UPDATE statement for all non-key fields regardless if any of them had actually changed or not.

EF5 can not handle Concurrency when Updating selective fields

I am using EF5 and Data First approach to Update entities.
I am using approach suggested by other questions to conditionally update only modified properties in the Entities.
Oki so here's the scenario My controller call Service with POCO objects and gets POCO objects from Service, The Service layer talks with Data layer which internally uses EF5 to retrieve entity from DB and Update them in DB.
The View data is loaded by controller from DTO object retrieved from Service layer.
User makes changes to View and Posts back JSON data to controller which gets mapped to DTO object in controller (courtesy MVC).
The controller makes call to Service layer with the DTO object (POCO) object.
The Service maps the POCO object to EF entity object and calls the Data layer's(i.e Repository) Update method passing in the EF entity.
In the Repository I fetch the existing entity from DB and call ApplyCurrentvaluesValues method, then I check if any properties are modified .
If properties are modified then I apply my custom logic to other entities which are not related to current entity and also Update the "UpdatedAdminId" & "UpdationDate" of current entity.
Post this I call "SaveChanges" method on Centext.
Every thing above I mentioned is working fine , except if I insert a break point in "SaveChanges" call and update some field modified by User to different value then "DbUpdateConcurrencyException" is not thrown by EF5.
i.e. I can get conditional Update & fire my custom logic when properties of my interest are modified to work perfectly.
But I am not getting error in case of the concurrency i.e the EF is not raising "DbUpdateConcurrencyException" in case a record is updated in between me fetching the record from DB , updating the record and saving it.
In real scenario there is a offline cron running which checks for newly created campaign and creates portfolio for them and marks the IsPortfolioCreated property below as true, in the mean time user can edit the campaign and the flag can be set to false even though the cron has created the portfolios.
To replicate the concurrency scenario I put a break point on SaveChanges and then Update the IsPortfolioCreated feild from MS-Sql enterprise manager for the same entity, but the "DbUpdateConcurrencyException" is not thrown even though the Data in Store has been updated.
Here's my code for reference,
Public bool EditGeneralSettings(CampaignDefinition campaignDefinition)
{
var success = false;
//campaignDefinition.UpdatedAdminId is updated in controller by retreiving it from RquestContext, so no its not comgin from client
var updatedAdminId = campaignDefinition.UpdatedAdminId;
var updationDate = DateTime.UtcNow;
CmsContext context = null;
GlobalMasterContext globalMasterContext = null;
try
{
context = new CmsContext(SaveTimeout);
var contextCampaign = context.CampaignDefinitions.Where(x => x.CampaignId == campaignDefinition.CampaignId).First();
//Always use this fields from Server, no matter what comes from client
campaignDefinition.CreationDate = contextCampaign.CreationDate;
campaignDefinition.UpdatedAdminId = contextCampaign.UpdatedAdminId;
campaignDefinition.UpdationDate = contextCampaign.UpdationDate;
campaignDefinition.AdminId = contextCampaign.AdminId;
campaignDefinition.AutoDecision = contextCampaign.AutoDecision;
campaignDefinition.CampaignCode = contextCampaign.CampaignCode;
campaignDefinition.IsPortfolioCreated = contextCampaign.IsPortfolioCreated;
var campaignNameChanged = contextCampaign.CampaignName != campaignDefinition.CampaignName;
// Will be used in the below if condition....
var originalSkeForwardingDomain = contextCampaign.skeForwardingDomain.ToLower();
var originalMgForwardingDomain = contextCampaign.mgForwardingDomain.ToLower();
//This also not firing concurreny exception....
var key = ((IObjectContextAdapter) context).ObjectContext.CreateEntityKey("CampaignDefinitions", campaignDefinition);
((IObjectContextAdapter)context).ObjectContext.AttachTo("CampaignDefinitions", contextCampaign);
var updated = ((IObjectContextAdapter)context).ObjectContext.ApplyCurrentValues(key.EntitySetName, campaignDefinition);
ObjectStateEntry entry = ((IObjectContextAdapter)context).ObjectContext.ObjectStateManager.GetObjectStateEntry(updated);
var modifiedProperties = entry.GetModifiedProperties();
//Even tried this , works fine but no Concurrency exception
//var entry = context.Entry(contextCampaign);
//entry.CurrentValues.SetValues(campaignDefinition);
//var modifiedProperties = entry.CurrentValues.PropertyNames.Where(propertyName => entry.Property(propertyName).IsModified).ToList();
// If any fields modified then only set Updation fields
if (modifiedProperties.Count() > 0)
{
campaignDefinition.UpdatedAdminId = updatedAdminId;
campaignDefinition.UpdationDate = updationDate;
//entry.CurrentValues.SetValues(campaignDefinition);
updated = ((IObjectContextAdapter)context).ObjectContext.ApplyCurrentValues(key.EntitySetName, campaignDefinition);
//Also perform some custom logic in other entities... Then call save changes
context.SaveChanges();
//If campaign name changed call a SP in different DB..
if (campaignNameChanged)
{
globalMasterContext = new GlobalMasterContext(SaveTimeout);
globalMasterContext.Rename_CMS_Campaign(campaignDefinition.CampaignId, updatedAdminId);
globalMasterContext.SaveChanges();
}
}
success = true;
}
catch (DbUpdateConcurrencyException ex)
{
//Code never enters here, if it does then I am planning to show the user the values from DB and ask him to retry
//In short Store Wins Strategy
//Code in this block is not complete so dont Stackies don't start commenting about this section and plague the question...
// Get the current entity values and the values in the database
var entry = ex.Entries.Single();
var currentValues = entry.CurrentValues;
var databaseValues = entry.GetDatabaseValues();
// Choose an initial set of resolved values. In this case we
// make the default be the values currently in the database.
var resolvedValues = databaseValues.Clone();
// Update the original values with the database values and
// the current values with whatever the user choose.
entry.OriginalValues.SetValues(databaseValues);
entry.CurrentValues.SetValues(resolvedValues);
}
catch (Exception ex)
{
if (ex.InnerException != null)
throw ex.InnerException;
throw;
}
finally
{
if (context != null) context.Dispose();
if (globalMasterContext != null) globalMasterContext.Dispose();
}
return success;
}

Entity framework it's not doing anything special about concurrency until you (as developer) configure it to check for concurrency problems.
You are trying to catch DbUpdateConcurrencyException, the documentation for this exception says: "Exception thrown by DbContext when it was expected that SaveChanges for an entity would result in a database update but in fact no rows in the database were affected. ", you can read it here
In a database first approach, you have to set the property 'Concurrency Mode' for column on 'Fixed' (the default is None). Look at this screenshot:
The column Version is a SQL SERVER TIMESTAMP type, a special type that is automatically updated every time the row changes, read about it here.
With this configuration, you can try with this simple test if all is working as expected:
try
{
using (var outerContext = new testEntities())
{
var outerCust1 = outerContext.Customer.FirstOrDefault(x => x.Id == 1);
outerCust1.Description += "modified by outer context";
using (var innerContext = new testEntities())
{
var innerCust1 = innerContext.Customer.FirstOrDefault(x => x.Id == 1);
innerCust1.Description += "modified by inner context";
innerContext.SaveChanges();
}
outerContext.SaveChanges();
}
}
catch (DbUpdateConcurrencyException ext)
{
Console.WriteLine(ext.Message);
}
In the example above the update from the inner context will be committed, the update from the outer context will thrown a DbUpdateConcurrencyException, because EF will try to update the entity using 2 columns as a filters: the Id AND the Version column.
Hope this helps!

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.

How to use Clutch for debugging SQL statements executed by the Entity Framework?

I am very new to the Entity Framework. Tried to save an object and it fails with the message
error in saving entities which do not make foreign key properties available
As something wrong happens when EF tries writing to the database, I wanted to see the actual query it is trying to execute. I am not yet using EF 6, so I can't use context.Database.Log. Some search told me that there is a library called Clutch Diagnostics which will help me.
I installed it from NuGet and set it up as described in this blog post. Basically, it involved adding the methods
public void CommandFailed(DbTracingContext context)
{
Debug.WriteLine("\nFAILED\n " + context.Command.CommandText);
// or Trace.WriteLine("\nFAILED\n " + context.Command.CommandText);
}
public void CommandExecuted(DbTracingContext context)
{
Debug.WriteLine("\nExecuted\n " + context.Command.CommandText);
// or Trace.WriteLine("\nExecuted\n " + context.Command.CommandText);
}
to a class which implements the IDbTracingListener interface, and adding
// Enable Tracing queries
DbTracing.Enable();
// Adding the listener (implementation of IDbTracingListener)
DbTracing.AddListener(new DbTracingListener());
to the application start method in Global.asax.
I expected to now see the SQL queries in my Debug window. But instead I got
What am I doing wrong? Did I miss something? Are my expectations wrong? Is the debug output the wrong place to look for the query? Is the listener meant to work for saving objects to the database?
My method for saving to the database is very simple,
if (keyword.ExtractedKeywords_ID == 0)
{
context.ExtractedKeywords.Add(keyword);
}
else
{
ExtractedKeyword dbEntry = context.ExtractedKeywords.Find(keyword.ExtractedKeywords_ID);
if (dbEntry != null)
{
dbEntry.CorrectSpelling = keyword.CorrectSpelling;
dbEntry.Embryonen = keyword.Embryonen;
dbEntry.ExcelNumber = keyword.ExcelNumber;
dbEntry.IsCell = keyword.IsCell;
dbEntry.IsOrgan = keyword.IsOrgan;
dbEntry.IsRecombinase = keyword.IsRecombinase;
dbEntry.IsReporter = keyword.IsReporter;
dbEntry.IsResearchTopic = keyword.IsResearchTopic;
dbEntry.ModificationStatus = keyword.ModificationStatus;
dbEntry.OriginalSpelling = keyword.OriginalSpelling;
dbEntry.Synonym = keyword.Synonym;
}
}
context.SaveChanges();
I have only tried it with brand-new objects (the if part gets executed), because I don't yet have any entries in the database table for going into the else part.

Entity Framework Update Problem

I am using Entity Framework & LINQ to retrieve data. I am having a problem with the following:
var customer= db.customers.where(c=>c.id==1);
customer.name=santhosh;
customer.city=hyd;
The fields are changing in the database before I call:
db.SaveChanges();
How do I avoid this?

As others have said, I believe that you are using your context in another place as well and that other location is calling savechanges and updating everything. Try doing what #Evan suggested with a using statment to make sure you have a fresh context.
AsNoTracking will not ensure that you get a entity that is not cached in the database, its purpose is to not put the objects inside the context. If you use AsNoTracking and then change the entities returned in the query you will need to attach them as modified to the context before calling savechanges or else they won't be updated.
var customer= db.customers.AsNoTracking().Single(c=>c.id==1);
customer.name=santhosh;
customer.city=hyd;
ctx.customers.Attach(customer);
ctx.ObjectStateManager.ChangeObjectState(customer, System.Data.EntityState.Modified);
I would have just commented on the other posts but don't have enough rep yet.

Check whether you are passing the db object to some other method, and SaveChanges() is called there?
Or check whether you have a catch block of an exception and you might be using SaveChanges() in the catch block to log error message?
(These are common programming mistakes)

The fields are changing in the database before I call
If you mean changing as in changing outside of application, changes in SQL Management Studio for example. Entity Framework cannot detect those changes, so as a result you might get stale objects that was cached by Entity Framework. To prevent receiving cached object and get the up-to-date values from database, use AsNoTracking.
Try putting AsNoTracking():
var customer= db.customers.AsNoTracking().where(c=>c.id==1);
customer.name=santhosh;
customer.city=hyd;
db.SaveChanges();
Or if your problem is to detect concurrent updates(unfortunate terminology, it doesn't apply to UPDATE only) to same row, use rowversion(aka timestamp) field type; then on your .NET code add Timestamp attribute on the property. Example: http://www.ienablemuch.com/2011/07/entity-framework-concurrency-checking.html
public class Song
{
[Key]
public int SongId { get; set; }
public string SongName { get; set; }
public string AlbumName { get; set; }
[Timestamp]
public virtual byte[] Version { get; set; }
}
UPDATE (after your comment):
If you really has no intent to persist your object changes to database. Try detaching the object.
Try this:
var customer= db.customers.where(c=>c.id==1);
db.Entry(customer).State = System.Data.EntityState.Detached; // add this
customer.name=santhosh;
customer.city=hyd;
db.SaveChanges();
That won't save your changes on name and city to database.
If you want something more robust(the above will fail an exception if the object was not yet attached), create a helper:
private static void Evict(DbContext ctx, Type t,
    string primaryKeyName, object id)
{           
    var cachedEnt =
        ctx.ChangeTracker.Entries().Where(x =>  
            ObjectContext.GetObjectType(x.Entity.GetType()) == t)
            .SingleOrDefault(x =>
        {
            Type entType = x.Entity.GetType();
            object value = entType.InvokeMember(primaryKeyName,
                                System.Reflection.BindingFlags.GetProperty,
null, x.Entity, new object[] { });
 
            return value.Equals(id);
        });
 
    if (cachedEnt != null)
        ctx.Entry(cachedEnt.Entity).State = EntityState.Detached;
}
To use: Evict(yourDbContextHere, typeof(Product), "ProductId", 1);
http://www.ienablemuch.com/2011/08/entity-frameworks-nhibernate.html

Can you give a little more of the surrounding code? Might be a little difficult without seeing how you are constructing your context.
This is how I typically handle updates (I hope it might give some insight):
using (var ctx = new myModel.myEntities())
{
int pollID = 1;
var poll = (from p in ctx.Polls
where p.PollID == pollID
select p).FirstOrDefault();
poll.Question = txtPoll.Text.Trim();
ctx.SaveChanges();
}

Jack Woodward, yours did not work for me.
I had to change it up a little for SQL Compact.
var customer= db.customers.AsNoTracking().Single(c=>c.id==1);
db.customers.Attach(customer);
customer.name=santhosh;
customer.city=hyd;
db.ObjectStateManager.ChangeObjectState(customer, System.Data.EntityState.Modified);
db.SaveChanges();
db.Dispose();
This worked alot better.