i tried this method that I created but it prompts me an error:
Realms.RealmInvalidObjectException:This object is detached. Was it deleted from the realm?'
public void deleteFromDatabase(List<CashDenomination> denom_list)
{
using (var transaction = Realm.GetInstance(config).BeginWrite())
{
Realm.GetInstance(config).Remove(denom_list[0]);
transaction.Commit();
}
}
what is the proper coding for deleting records from database in realm in C# type of coding?
You are doing it the right way. The error message you are getting indicates that the object was removed already. Are you sure it still exists in the realm?
UPDATE:
I decided to update this answer because my comment on the other answer was a bit hard to read.
Your original code should work fine. However, if you want deleteFromDatabase to accept lists with CashDenomination instances that either have been removed already or perhaps were never added to the realm, you would need to add a check. Furthermore, note that you should hold on to your Realm instance and use it in the transaction you created. In most cases, you want to keep it around even longer, though there is little overhead to obtaining it via GetInstance.
public void deleteFromDatabase(List<CashDenomination> denom_list)
{
if (!denom_list[0].IsValid) // If this object is not in the realm, do nothing.
return;
var realm = Realm.GetInstance(config);
using (var transaction = realm.BeginWrite())
{
realm.Remove(denom_list[0]);
transaction.Commit();
}
}
Now, if you want to use identifiers, you could look it up like you do, but still just use Remove:
public void deleteFromDatabase(int denom_id)
{
var realm = Realm.GetInstance(config);
var denom = realm.All<CashDenomination>().FirstOrDefault(c => c.denom_id == denom_id);
if (denom == null) // If no entry with this id exists, do nothing.
return;
using (var transaction = realm.BeginWrite())
{
realm.Remove(denom);
transaction.Commit();
}
}
Finally, if your CashDenomination has denom_id marked as PrimaryKey, you could look it up like this:
public void deleteFromDatabase(int denom_id)
{
var realm = Realm.GetInstance(config);
var denom = realm.ObjectForPrimaryKey<CashDenomination>(denom_id);
if (denom == null) // If no entry with this id exists, do nothing.
return;
using (var transaction = realm.BeginWrite())
{
realm.Remove(denom);
transaction.Commit();
}
}
public void deleteFromDatabase(Realm realm, long cashDenominatorId)
{
realm.Write(() =>
{
var cashDenominator = realm.All<Person>().Where(c => c.Id == cashDenominatorId);
Realm.RemoveRange<CashDenomination>(((RealmResults<CashDenomination>)cashDenominator));
});
}
Which you would call as
Realm realm = Realm.GetInstance(config);
var denom_list = ...
// ...
deleteFromDatabase(realm, denom_list[0].id);
I already made it having this code :) thanks to #EpicPandaForce 's answer.
public void deleteFromDatabase(int denom_ID, int form_ID)
{
//Realm realm;
//and
//RealmConfiguration config = new RealmConfiguration(dbPath, true);
//was initialized at the top of my class
realm = Realm.GetInstance(config);
realm.Write(() =>
{
var cashflow_denom = realm.All<CashDenomination>().Where(c => c.denom_id == denom_ID);
var cashflow_form = realm.All<CashForm>().Where(c => c.form_id == form_ID);
realm.RemoveRange(((RealmResults<CashDenomination>)cashflow_denom));
realm.RemoveRange(((RealmResults<CashForm>)cashflow_form));
});
}
it is now deleting my data without exception :)
Related
I've seen a lot of posts about this, but I'm still not quite sure what the answer is. I inherited some code that is handling items one by one. It does a bunch of stuff (it's somewhat CPU intensive), then needs to save data to the database, and update the status of the item. It uses EF.
Here is the existing method:
private void CheckForThingsToDo(IContainer container)
{
var finished = false;
while (!finished)
{
using (var scope = container.BeginLifetimeScope("Console Request"))
{
var queries = scope.Resolve<IQueries>();
var commands = scope.Resolve<ICommands>();
var context = scope.Resolve<IContext>();
var nextItem = queries.GetNextItem();
finished = (nextItem == null);
if (finished) continue;
using (var transaction = context.BeginTransaction())
{
if (nextItem == null) return;
try
{
commands.ProcessItem(nextItem.Id); // this is somewhat CPU intensive
transaction.Commit();
}
catch(Exception ex)
{
_logger.Error(ex.Message, ex);
}
}
}
}
}
I would like to be able to run these in parallel because it's maxing out one core and the rest of the server is sitting there.
private void CheckForThingsToDoParallel(IContainer container)
{
using (var scope = container.BeginLifetimeScope("Console Request"))
{
var context0 = new EntityFrameworkRecordkeepingContext();
var queries = new AccountTransactionQueries(context0, mapper);
var items = queries.GetItems();
Parallel.ForEach(items,
new ParallelOptions { MaxDegreeOfParallelism = 4 },
() => new EntityFrameworkRecordkeepingContext(),
(item, parallelLoopState, context) =>
{
try
{
var queries = new Queries(context);
var repo = new Repository(context);
var commands = new Commands(repo, queries);
using (var transaction = context.BeginTransaction())
{
commands.ProcessItem(nextBatchItem);
transaction.Commit();
}
}
catch (Exception ex)
{
_logger.Error(ex.Message, ex);
}
return context;
},
(context) =>
{
context.Dispose();
});
}
}
Should something like that work? It works some of the time. But I end up getting this error:
DbUpdateConcurrencyException: Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded
Each item is a separate thing, so any inserts done in relation to one item should not impact another set of inserts from a different item.
I feel like I might be missing something obvious. Some of the parallel code is me trying to figure stuff out. Any thoughts? I need a push in the right direction.
In my method below which is written using c# in asp.net core, I am getting error when executing any of the below update statements. What is the issue with using await SaveContextAsync(); I have noticed I dont get error when only using SaveContext();
The error that I am getting is as follows
Cannot access a disposed object. A common cause of this error is disposing a context that was resolved from dependency injection
and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling Dispose()
on the context, or wrapping the context in a using statement. If you are using dependency injection, you should let the dependency
injection container take care of disposing context instances.
Object name: 'FXDB1Context'.
I am not sure why I am getting this error.
public async Task<IdentityResult> ApproveUserChangeRequest(UserChangeRequest userChangeRequest, string approvedByAuthUserName, string authApplicationName)
{
var userChangeRequestRepository = UserChangeRequestRepository.GetAllAsList();
var userChangeRequestApprovalRepository = UserChangeRequestApprovalRepository.GetAllAsList();
var appSettingRepository = AppSettingRepository.GetAllAsList();
var clientCompanyContactRepository = ClientCompanyContactRepository.GetAllAsList();
var applicationUserRepo = ApplicationUserRepo.GetAllAsList();
int approvedByAuthUserID = GetApprovedByUserId(authApplicationName, approvedByAuthUserName);
// Check if UserChangeRequest is still Pending
bool isUserChangeRequestPending = userChangeRequestRepository.Any(x => x.Id == userChangeRequest.Id && x.ChangeStatus == "Pending");
if (isUserChangeRequestPending && approvedByAuthUserID > 0)
{
// Inserting record in the UserChangeRequestApproval table
InsertUserChangeRequestApproval(userChangeRequest);
await SaveContextAsync();
using (var userTransaction = Context.Database.BeginTransaction())
{
using (var securityTransaction = _securityContext.Database.BeginTransaction())
{
try
{
//Get the Number of approval required for Internal and External Users
int? internalApprovalsRequired = GetApprovals("InternalUserChangeRequestApprovalsRequired", appSettingRepository);
int? externalApprovalsRequired = GetApprovals("ExternalUserChangeRequestApprovalsRequired", appSettingRepository);
//Get the name of the application the auth user belongs to
var authUserApplicationName = GetApplicationName(userChangeRequest.AuthUserId);
//Get the Number of approvals for the request
var numberOfAprovals = userChangeRequestApprovalRepository.Where(x => x.UserChangeRequestId == userChangeRequest.Id).Count();
//If the number of approvals is equal or greater than the Approvals required then Update AppUser or Contact details
if ((authUserApplicationName == "ArgentexTrader" && numberOfAprovals >= internalApprovalsRequired) || (authUserApplicationName == "ArgentexClient" && numberOfAprovals >= externalApprovalsRequired))
{
//Updating the clientcontact table
UpdateClientContact(userChangeRequest, clientCompanyContactRepository);
//Updating the auth user table
UpdateAuthUser(userChangeRequest);
//Updating the IdentityDB user table
UpdateIdentityDBUser(userChangeRequest, applicationUserRepo);
//Updating the UserChangeRequest table
userChangeRequest.ChangeStatus = "Approved";
UserChangeRequestRepository.Update(userChangeRequest);
await SaveContextAsync();
userTransaction.Commit();
securityTransaction.Commit();
return IdentityResult.Success;
}
}
catch (Exception ex)
{
userTransaction.Rollback();
securityTransaction.Rollback();
_logger.Error(ex);
return IdentityResult.Failed(new IdentityError { Description = ex.Message });
}
}
}
}
return null;
}
The error says that a resolved context is been trying to made Disposable.
For More Information: Using Statements in C#
using statement is a scope only process, so this error means that your program tries to use the same instances of "context" in somewhere else, which it cant use it, because as I mentioned it is a "scope only" process.
In your example:
using (var userTransaction = Context.Database.BeginTransaction())
{
using (var securityTransaction = _securityContext.Database.BeginTransaction())
{
}
}
You can make it simple and dont use a using scope or you can be sure that, the context is just used in those using scopes.
When I try to update this object in EF6 I get an error stating more than 1 entity has this primary key. Looking at this DB I know this to be untrue(from what I can see).
I need to be able to update a second object based on one of the properties on the posted object. The code below produces the error. I have left in commented out pieces that I have tried to get this to work.
public async Task<ActionResult> Edit(PricingRule pricingRule)
{
if(ModelState.IsValid)
{
var currentUser = await serv.UserManager.FindByIdAsync(User.Identity.GetUserId());
var company = currentUser.Company;
//var entityRule = serv.PricingService.PricingRules.Get(pricingRule.PricingRuleId);
//If this is the first rule, set it to the company default
var rulesCount = company.PricingRules.Count;
if (rulesCount <= 1 || company.DefaultPricingRule == null)
pricingRule.DefaultPricingRule = true;
//Make sure no other rules are marked as default, and update the company with this rule as default
if (pricingRule.DefaultPricingRule)
{
if (company.DefaultPricingRule != null)
{
var oldRule = serv.PricingService.PricingRules.Get(company.DefaultPricingRule.PricingRuleId);
oldRule.DefaultPricingRule = false;
//serv.PricingService.PricingRules.Update(oldRule);
}
company.DefaultPricingRule = pricingRule;
serv.CoreService.Companies.Update(company);
}
serv.PricingService.PricingRules.Update(pricingRule);
await serv.SaveAllChangesAsync();
return RedirectToAction("Index");
}
return View(pricingRule);
}
Whether or not it is the best practice or how it should technically be done, this is how I solved my problem.
The edited object I was passing in, needed to be marked as modified first, before doing any other operations. I am assuming this is because the context could then grab it and all other operations regarding it would be done "within context". Other wise I think it was trying to add a new object if I tried to attach it to company.DefaultPricingRule.
public async Task<ActionResult> Edit(PricingRule pricingRule)
{
if(ModelState.IsValid)
{
serv.PricingService.PricingRules.Update(pricingRule);
var currentUser = await serv.UserManager.FindByIdAsync(User.Identity.GetUserId());
var company = currentUser.Company;
//If this is the first rule, set it to the company default
var rulesCount = company.PricingRules.Count;
if (rulesCount <= 1 || company.DefaultPricingRule == null)
pricingRule.DefaultPricingRule = true;
//Make sure no other rules are marked as default, and update the company with this rule as default
if (pricingRule.DefaultPricingRule)
{
if (company.DefaultPricingRule != null)
{
var oldRule = serv.PricingService.PricingRules.Get(company.DefaultPricingRule.PricingRuleId);
oldRule.DefaultPricingRule = false;
serv.PricingService.PricingRules.Update(oldRule);
}
company.DefaultPricingRule = pricingRule;
serv.CoreService.Companies.Update(company);
}
await serv.SaveAllChangesAsync();
return RedirectToAction("Index");
}
return View(pricingRule);
}
If Anyone has a comment on if this is best practice or if there is a better way to do it, I gladly take criticism.
I am new at Entity Framework Code first and I am building a small app to get used to it.When the site runs for the first time I access existing catalog values inside the database and display this in a drop down using razor.
public void GetCats()
{
using (context = new RecipeContext())
{
try
{
var query = (from r in context.Catalogues
select r).Distinct().ToList();
catalogues = query.Select(t => t.CatalogueName.ToString()).ToList();
catalogues.Sort();
}
catch (Exception exe)
{
labMessage = exe.Message;
}
}
}
Now when I try to add Catalogue values to the context I get the above error.
public void AddCatalogue(string catalogueName)
{
using(context = new RecipeContext())
{
try
{
catalogueName = catalogueName.ToLower();
var catalogue = new RecipeCatalogue { CatalogueName = catalogueName };
if (context.Catalogues.Where(t => t.CatalogueName == catalogueName).Count() > 0)
{
labMessage = "The value already exists";
CatalogueNameAdded = false;
return;
}
context.Catalogues.Add(catalogue);
context.SaveChanges();
catalogueNameAdded = true;
labMessage = "a new catalogue record was added";
}
catch (Exception exe)
{
catalogueNameAdded = false;
labMessage = exe.Message;
}
}
}
The values are being added to the database however but still get the above exception.
Advice perhaps as to why I get this error. This is my Controller method which calls the above method.
[HttpPost]
public JsonResult AddNewCatalogue(string catalogueName)
{
ViewModel model = new ViewModel();
model.AddCatalogue(catalogueName);
return Json(new { ViewModel = model });
}
Is context a field in your model?
I think you shouldn't assign to a field in a using statement. At the closing brace of the using context will be disposed. If you access that field in another place (without re-assigning) you are accessing a disposed object that might raise the exception you are getting.
Try changing your using statetments like this using (var context = new RecipeContext()).
(note var before context) and drop the field.
Your context is being disposed when the using block where you're performing your query is exited. That's the whole point of the using statement:
using(context = new RecipeContext()) {
// ...
}
// context has been disposed at this point
Instead of a using statement, give your class a field to hold a reference to it.
private RecipeContext _context;
public void GetCats() {
_context = new RecipeContext();
// ...
}
public void AddCatalogue(string catalogueName) {
// Use _context here
}
Just make sure that at some point, you call _context.Dispose(). Also, it's probably better to create the context in the constructor or someplace else that's only called once, prior to performing any operations with it.
Just my 2 cents:
The above answers are correct! If you're using some pattern like a repository, I sugest to implement it as a singleton! This way your objects will not be detached, and you're context will not be disposed!
Ok here is the deal. using my Model to raise the Child_Update() Method. I know it is not good but im just learing right now. Now i given my Business class as Parameter to Change the already given rows.
It's doin everything fine without any error Messages and there is also no null variable but it's not changing anything in the database.
here i'm using the selectedIndex to choose the right items to update
public void ExecuteAngestellte(object obj)
{
try
{
_selectedIndex.Child_Update(new Farbe { FarbauswahlNr = SelectedIndex.FarbauswahlNr, Kurztext = SelectedIndex.Kurztext, Ressource = SelectedIndex.Ressource, Vari1 = SelectedIndex.Vari1, Vari2 = SelectedIndex.Vari2 });
}
catch (Exception e)
{
MessageBox.Show(e.ToString());
}
}
and here's the child update
public void Child_Update(Farbe data)
{
using (var ctx =Csla.Data.ObjectContextManager<TestDBEntities>.GetManager(EntitiesDatabase.Name))
{
var objectStateManager = ctx.ObjectContext.ObjectStateManager;
var _data = new Datenbank.Farbe();
_data.FarbauswahlNr = data.FarbauswahlNr;
_data.Kurztext = data.Kurztext;
_data.Ressource = data.Ressource;
_data.Var1 = data.Vari1;
_data.Vari2 = data.Vari2;
ctx.ObjectContext.SaveChanges();
}
}
thx for help
as far as I can tell, your _data is not part of the datacontext
I am not sure what the variables all mean so here is a simple update I use for a single record with entity framework
public void UpdateTable(int idRecord, YourContext Context)
{
MyRecord = Context.MyTable.Find(idRecord);
myRecord.Column = "New Value";
Context.SaveChanges();
}
so I think you need to do:
var MyData = ctx.ObjectContext.TableName.Find(id)
I am assuming you are using entity framework. Does this help?