I'm developing a multitenant application and would like to have to option to remove a tenant. This however seems to be less trivial than one would assume.
My goal is to delete all references to the tenant everywhere in the database. I understand that Tenant is Soft-Delete, but I since I don't want my database to fill up with old meaningless data I've tried disabling the soft-delete filter.
Here is some code that I've tried:
using (_unitOfWorkManager.Current.DisableFilter(AbpDataFilters.SoftDelete))
{
await TenantRepository.DeleteAsync(x => x.Id == tenantId);
}
This did not work. The tenant is marked as "IsDeleted" but not removed.
Then I figured that maybe it has something to do with UnitOfWork so I made sure no UnitOfWork was active and then manually controlled it:
using (var unitOfWork = _unitOfWorkManager.Begin())
{
// the codeblock above went here
unitOfWork.Complete();
}
This did not work, same result. And this is just the AbpTenant table. I'm also trying to delete from all other tables. For example AbpSettings and AbpLanguages. It's very unclear to me how to do that at all - the "managers" doesn't contain any Delete functions.
I tried creating IRepository for these entities but it does not work. The error reads
The type Abo.Configuration.Setting cannot be used as a type parameter TEntity in the generic type or method IRepository. There is no implicit reference conversion from Abp.Configuration.Setting to Abo.Domain.Entities.IEntity.
That leaves me with the option to use the DataContext directly:
using (EntityFramework.MyDbContext db = new EntityFramework.MyDbContext())
{
List<PermissionSetting> perms = await db.Permissions.Where(x => x.TenantId == tenantId).ToListAsync();
for (int i=0; i<perms.Count(); i++)
{
db.Permissions.Remove(perms[i]);
}
// I also tried deleting them in bulk at first
// ((DbSet<PermissionSetting>)db.Permissions).RemoveRange(db.Permissions.Where(x => x.TenantId == tenantId));
await db.SaveChangesAsync();
}
I tried that with and without UnitOfWork.
But it simply does not get deleted from the database. I'm getting no errors or Exceptions.
Why does it not get deleted? How can I delete it? Surely it must be possible?
since I don't want my database to fill up with old meaningless data I've tried disabling the soft-delete filter.
From the question on Disable SoftDelete for AbpUserRole:
protected override void CancelDeletionForSoftDelete(EntityEntry entry)
{
if (IsSoftDeleteFilterEnabled)
{
base.CancelDeletionForSoftDelete(entry);
}
}
The type Abo.Configuration.Setting cannot be used as a type parameter TEntity in the generic type or method IRepository. There is no implicit reference conversion from Abp.Configuration.Setting to Abo.Domain.Entities.IEntity.
Inject IRepository<Setting, long> instead of IRepository<Setting>.
That leaves me with the option to use the DataContext directly
...
But it simply does not get deleted from the database. I'm getting no errors or Exceptions.
From the documentation on Data Filters:
using (_unitOfWorkManager.Current.DisableFilter(AbpDataFilters.MayHaveTenant))
{
using (var db = new ...)
{
// ...
}
}
That said, there is no way to easily delete related tenant data completely. Consider writing SQL.
Related
So am using AspNetCore 1.0 with EFCore 1.0, both latest releases as far as I am aware.
Executing a query to delete an object using the FromSql method on a DbSet throws an exception. Both the code and exception are below.
public void DeleteColumn(int p_ColumnID)
{
int temp = p_ColumnID;
string query = "DELETE FROM Columns WHERE ID = {0}";
var columnsList = m_context.Columns.FromSql(query, p_ColumnID).ToList();
foreach (Columns c in columnsList)
{
m_context.Columns.Remove(c);
}
m_context.SaveChanges();
}
After executing the FromSql call, I get the following exception
An exception of type 'System.NotSupportedException' occurred in Remotion.Linq.dll but was not handled in user code
Additional information: Could not parse expression 'value(Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1[ASPNET5_Scrum_Tool.Models.Columns]).FromSql("DELETE FROM Columns WHERE ID = {0}", __p_0)': This overload of the method 'Microsoft.EntityFrameworkCore.RelationalQueryableExtensions.FromSql' is currently not supported.
I have no clue how to fix this error and from Googling I have come across no similar problems.
I am also wondering, if the query/code was successful it would return an 'IQueryable object. Would that solely contain the results of the query, in this case the specific Column object to delete?
FromSql is intended to allow you to compose a custom SQL SELECT statement that will return entities. Using it with a DELETE statement is not appropriate here, since your goal is to load the records you want to delete and then delete them using the default Entity Framework mechanism. A Delete statement generally does not return the records deleted (though there are ways to accomplish that). Even if they did, the records will already be deleted and so you won't want to iterate over them and do a Remove on them.
The most straightforward way to do what you want might be to use the RemoveRange method in combination with a Where query.
public void DeleteColumn(int p_ColumnID)
{
m_context.Columns.RemoveRange(m_context.Columns.Where(x => x.ID == p_ColumnID))
m_context.SaveChanges();
}
Alternately, if you want to load your entities and iterate manually through them to
public void DeleteColumn(int p_ColumnID)
{
columnList = m_context.Columns.Where(x => x.ID == p_ColumnID);
foreach (Columns c in columnsList)
{
m_context.Columns.Remove(c);
}
m_context.SaveChanges();
}
If you really want to issue the Delete statement manually, as suggested by Mike Brind, use an ExecuteSqlCommand method similar to:
public void DeleteColumn(int p_ColumnID)
{
string sqlStatement = "DELETE FROM Columns WHERE ID = {0}";
m_context.Database.ExecuteSqlCommand(sqlStatement, p_ColumnID);
}
I had the same exception in a case where I did not use delete statement. Turns out I was using the In-Memory Database. Since it is not a real database you can't use FromSQL.
I was able to follow the instruction on adding data, that part was easy and understandable. But when I tried to follow instructions for editing data, I'm completely lost.
I am following the todo sample, which works quite well, but when I tried to add to my own project using the same principle, nothing works.
in my controller, I have the following:
function listenForPropertyChanged() {
// Listen for property change of ANY entity so we can (optionally) save
var token = dataservice.addPropertyChangeHandler(propertyChanged);
// Arrange to remove the handler when the controller is destroyed
// which won't happen in this app but would in a multi-page app
$scope.$on("$destroy", function () {
dataservice.removePropertyChangeHandler(token);
});
function propertyChanged(changeArgs) {
// propertyChanged triggers save attempt UNLESS the property is the 'Id'
// because THEN the change is actually the post-save Id-fixup
// rather than user data entry so there is actually nothing to save.
if (changeArgs.args.propertyName !== 'Id') { save(); }
}
}
The problem is that any time I change a control on the view, the propertyChanged callback function never gets called.
Here's the code from the service:
function addPropertyChangeHandler(handler) {
// Actually adds any 'entityChanged' event handler
// call handler when an entity property of any entity changes
return manager.entityChanged.subscribe(function (changeArgs) {
var action = changeArgs.entityAction;
if (action === breeze.EntityAction.PropertyChange) {
handler(changeArgs);
}
});
}
If I put a break point on the line:
var action = changeArgs.entityAction;
In my project, it never reaches there; in the todo sample, it does! It completely skips the whole thing and just loads the view afterwards. So none of my callback functions work at all; so really, nothing is subscribed.
Because of this, when I try to save changes, the manager.hasChanges() is always false and nothing happens in the database.
I've been trying for at least 3 days getting this to work, and I'm completely dumbfounded by how complicated this whole issue has been for me.
Note: I'm using JohnPapa's HotTowel template. I tried to follow the Todo editing functionality to a Tee.. and nothing is working the way I'd like it to.
Help would be appreciated.
The whole time I thought the problem was in the javascript client side end of things. Turned out that editing doesn't work when you created projected DTOs.
So in my server side, I created a query:
public IQueryable<PersonDTO> getPerson(){
return (from _person in ContextProvider.Context.Queries
select new PersonDTO
{
Id = _person.Id,
FirstName = _person.FirstName,
LastName = _person.LastName
}).AsQueryable();
}
Which just projected a DTO to send off to the client. This did work with my app in fetching data and populating things. So this is NOT wrong. Using this, I was able to add items and fetch items, but there's no information that allowed the entitymanager to know about the item. When I created an item, the entitymanager has a "createEntity" which allowed me to tell the entitymanager which item to use.. in my case:
manager.createEntity(person, initializeValues);
Maybe if there was a "manager.getEntity" maybe that would help?
Anyways, I changed the above query to get it straight from the source:
public IQueryable<Person> getPeople(){
return ContextProvider.Context.People;
}
Note ContextProvider is:
readonly EFContextProvider<PeopleEntities> ContextProvider =
new EFContextProvider<PeopleEntities>();
So the subscribe method in the javascript checks out the info that's retrieved straight from the contextual object.. interesting. Just wish I didn't spend 4 days on this.
Background:
From another question here at SO I have a Winforms solution (Finance) with many projects (fixed projects for the solution).
Now one of my customers asked me to "upgrade" the solution and add projects/modules that will come from another Winforms solution (HR).
I really don't want to keep these projects as fixed projects on the existing finance solution. For that I'm trying to create plugins that will load GUI, business logic and the data layer all using MEF.
Question:
I have a context (DbContext built to implment the Generic Repository Pattern) with a list of external contexts (loaded using MEF - these contexts represent the contexts from each plugin, also with the Generic Repository Pattern).
Let's say I have this:
public class MainContext : DbContext
{
public List<IPluginContext> ExternalContexts { get; set; }
// other stuff here
}
and
public class PluginContext_A : DbContext, IPluginContext
{ /* Items from this context */ }
public class PluginContext_B : DbContext, IPluginContext
{ /* Items from this context */ }
and within the MainContext class, already loaded, I have both external contexts (from plugins).
With that in mind, let's say I have a transaction that will impact both the MainContext and the PluginContext_B.
How to perform update/insert/delete on both contexts within one transaction (unity of work)?
Using the IUnityOfWork I can set the SaveChanges() for the last item but as far as I know I must have a single context for it to work as a single transaction.
There's a way using the MSDTC (TransactionScope) but this approach is terrible and I'd reather not use this at all (also because I need to enable MSDTC on clients and server and I've had crashes and leaks all the time).
Update:
Systems are using SQL 2008 R2. Never bellow.
If it's possible to use TransactionScope in a way that won't scale to MSDTC it's fine, but I've never achieved that. All the time I've used TransactionScope it goes into MSDTC. According to another post on SO, there are some cases where TS will not go into MSDTC: check here. But I'd really prefer to go into some other way instead of TransactionScope...
If you are using multiple contexts each using separate connection and you want to save data to those context in single transaction you must use TransactionScope with distributed transaction (MSDTC).
Your linked question is not that case because in that scenario first connection do not modify data so it can be closed prior to starting the connection where data are modified. In your case data are concurrently modified on multiple connection which requires two-phase commit and MSDTC.
You can try to solve it with sharing single connection among multiple contexts but that can be quite tricky. I'm not sure how reliable the following sample is but you can give it a try:
using (var connection = new SqlConnection(connnectionString))
{
var c1 = new Context(connection);
var c2 = new Context(connection);
c1.MyEntities.Add(new MyEntity() { Name = "A" });
c2.MyEntities.Add(new MyEntity() { Name = "B" });
connection.Open();
using (var scope = new TransactionScope())
{
// This is necessary because DbContext doesnt't contain necessary methods
ObjectContext obj1 = ((IObjectContextAdapter)c1).ObjectContext;
obj1.SaveChanges(SaveOptions.DetectChangesBeforeSave);
ObjectContext obj2 = ((IObjectContextAdapter)c2).ObjectContext;
obj2.SaveChanges(SaveOptions.DetectChangesBeforeSave);
scope.Complete();
// Only after successful commit of both save operations we can accept changes
// otherwise in rollback caused by second context the changes from the first
// context will be already accepted = lost
obj1.AcceptAllChanges();
obj2.AcceptAllChanges();
}
}
Context constructor is defined as:
public Context(DbConnection connection) : base(connection,false) { }
The sample itself worked for me but it has multiple problems:
First usage of contexts must be done with closed connection. That is the reason why I'm adding entities prior to opening the connection.
I rather open connection manually outside of the transaction but perhaps it is not needed.
Both save changes successfully run and Transaction.Current has empty distributed transaction Id so it should be still local.
The saving is much more complicated and you must use ObjectContext because DbContext doesn't have all necessary methods.
It doesn't have to work in every scenario. Even MSDN claims this:
Promotion of a transaction to a DTC may occur when a connection is
closed and reopened within a single transaction. Because the Entity
Framework opens and closes the connection automatically, you should
consider manually opening and closing the connection to avoid
transaction promotion.
The problem with DbContext API is that it closes and reopens connection even if you open it manually so it is a opened question if API always correctly identifies if it runs in the context of transaction and do not close connection.
#Ladislav Mrnka
You were right from the start: I have to use MSDTC.
I've tried multiple things here including the sample code I've provided.
I've tested it many times with changed hare and there but it won't work. The error goes deep into how EF and DbContext works and for that to change I'd finally find myself with my very own ORM tool. It's not the case.
I've also talked to a friend (MVP) that know a lot about EF too.
We have tested some other things here but it won't work the way I want it to. I'll end up with multiple isolated transactions (I was trying to get them together with my sample code) and with this approach I don't have any way to enforce a full rollback automatically and I'll have to create a lot of generic/custom code to manually rollback changes and here comes another question: what if this sort of rollback fails (it's not a rollback, just an update)?
So, the only way we found here is to use the MSDTC and build some tools to help debug/test if DTC is enabled, if client/server firewalls are ok and all that stuff.
Thanks anyway.
=)
So, any chance this has changed by October 19th? All over the intertubes, people suggest the following code, and it doesn't work:
(_contextA as IObjectContextAdapter).ObjectContext.Connection.Open();
(_contextB as IObjectContextAdapter).ObjectContext.Connection.Open();
using (var transaction = new TransactionScope(TransactionScopeOption.Required, new TransactionOptions{IsolationLevel = IsolationLevel.ReadUncommitted, Timeout = TimeSpan.MaxValue}))
{
_contextA.SaveChanges();
_contextB.SaveChanges();
// Commit the transaction
transaction.Complete();
}
// Close open connections
(_contextA as IObjectContextAdapter).ObjectContext.Connection.Close();
(_contextB as IObjectContextAdapter).ObjectContext.Connection.Close();
This is a serious drag for implementing a single Unit of Work class across repositories. Any new way around this?
To avoid using MSDTC (distributed transaction):
This should force you to use one connection within the transaction as well as just one transaction. It should throw an exception otherwise.
Note: At least EF6 is required
class TransactionsExample
{
static void UsingExternalTransaction()
{
using (var conn = new SqlConnection("..."))
{
conn.Open();
using (var sqlTxn = conn.BeginTransaction(System.Data.IsolationLevel.Snapshot))
{
try
{
var sqlCommand = new SqlCommand();
sqlCommand.Connection = conn;
sqlCommand.Transaction = sqlTxn;
sqlCommand.CommandText =
#"UPDATE Blogs SET Rating = 5" +
" WHERE Name LIKE '%Entity Framework%'";
sqlCommand.ExecuteNonQuery();
using (var context =
new BloggingContext(conn, contextOwnsConnection: false))
{
context.Database.UseTransaction(sqlTxn);
var query = context.Posts.Where(p => p.Blog.Rating >= 5);
foreach (var post in query)
{
post.Title += "[Cool Blog]";
}
context.SaveChanges();
}
sqlTxn.Commit();
}
catch (Exception)
{
sqlTxn.Rollback();
}
}
}
}
}
Source:
http://msdn.microsoft.com/en-us/data/dn456843.aspx#existing
Psssst...!
Read on, by all means. But I can tell you here that the problem had nothing to do with the DataContext, but with Dependency Injection. I have left the question up, as it documents one possible issue with the "row not found or changed error" that has nothing to do with real world concurrency conflicts.
It seems the problems have been caused by badly written dependency injection. Or rather, I am beginning to believe, by default lifecycle management by the DI container I used.
The problem was that I used a DataContext as a constructor argument that was supplied by Ninject. It seems that the default behaviour was to cache this DataContext, leading to all manner of unexpected behaviour. I will ask a separate question about this.
Anyway, what follows is my original question, which as you will see, misses the real cause of the issue by a mile...
The Problem
I am getting a number of errors that imply that the DataContext, or rather, the way I am using the DataContext is getting out of synch.
The error occurs on db.SubmitChanges() where db is my DataContext instance. The error is:
Row not found or changed.
The problem only occurs intermitently, for example, adding a row then deleting it. If I stop the dev server and restart, the added row is there and I can delete it no problem.
Ie, it seems that the problem is related to the DataContext losing track of the rows that have been added.
IMPORTANT:
Before anyone votes to close this thread, on the basis of it being a duplicate, I have checked the sql server profiler and there is no "Where 0 = 1" in the SQL.
I have also recreated the dbml file, so am satisfied that the database schema is in synch with the schema represented by the dbml file.
Ie, no cases of mismatched nullable/not nullable columns, etc.
My Diagnosis (for what it is worth):
The problem seems (to me) related to how I am using the DataContext. I am new to MVC, Repositories and Services patterns, so suspect that I have wired things up wrong.
The Setup
Simple eLearning app in its early stages. Pupils need to be able to add and delete courses (Courses table) to their UserCourses.
To do this, I have a service that gets a specific DataContext instance Dependency Injected into its constructor.
Service Class Constructor:
public class SqlPupilBlockService : IPupilBlockService
{
DataContext db;
public SqlPupilBlockService(DataContext db)
{
this.db = db;
CoursesRepository = new SqlRepository<Course>(db);
UserCoursesRepository = new SqlRepository<UserCourse>(db);
}
// Etc, etc
}
The CoursesRepository and UserCoursesRepository are both private properties of the service class that are of type IRepository (just a simple generic repository interface).
SqlRepository Code:
public class SqlRepository<T> : IRepository<T> where T : class
{
DataContext db;
public SqlRepository(DataContext db)
{
this.db = db;
}
#region IRepository<T> Members
public IQueryable<T> Query
{
get { return db.GetTable<T>(); }
}
public List<T> FetchAll()
{
return Query.ToList();
}
public void Add(T entity)
{
db.GetTable<T>().InsertOnSubmit(entity);
}
public void Delete(T entity)
{
db.GetTable<T>().DeleteOnSubmit(entity);
}
public void Save()
{
db.SubmitChanges();
}
#endregion
}
The two methods for adding and deleting UserCourses are:
Service Methods for Adding and Deleting UserCourses:
public void AddUserCourse(int courseId)
{
UserCourse uc = new UserCourse();
uc.IdCourse = courseId;
uc.IdUser = UserId;
uc.DateCreated = DateTime.Now;
uc.DateAmended = DateTime.Now;
uc.Role = "Pupil";
uc.CourseNotes = string.Empty;
uc.ActiveStepIndex = 0;
UserCoursesRepository.Add(uc);
UserCoursesRepository.Save();
}
public void DeleteUserCourse(int courseId)
{
var uc = (UserCoursesRepository.Query.Where(x => x.IdUser == UserId && x.IdCourse == courseId)).Single();
UserCoursesRepository.Delete(uc);
UserCoursesRepository.Save();
}
Ajax
I am using Ajax via Ajax.BeginForm
I don't think that is relevant.
ASP.NET MVC 3
I am using mvc3, but don't think that is relevant: the errors are related to model code.
The problem only occurs intermitently,
for example, adding a row then
deleting it. If I stop the dev server
and restart, the added row is there
and I can delete it no problem.
Your code does not show what the link is between the Added Row and the Delete/Update. Your Add() doesn't return an object reference.
I'm thinking you are missing a Refresh (ie reload the object after Insert). Is your IdCourse also the PK in the Table?
Edit:
Further research has revealed that the problem is with the dependency injection.
The problem was related to how Dependency Injection manages the items it creates. Google for 'lifecycle management' in IoC or DI. Essentially, DI cached a DataContext constructor argument that I injected.
For a way to solve this using the Factory Pattern, see this thread:
Ninject caching an injected DataContext? Lifecycle Management?
The accepted answer solved it all.
am getting this error on this code (this is an MVC project into which I am trying to integrate Entity Framework):
List<string> consultantSchoolList = new List<string>();
// districts managed by consultant
IQueryable<string> consultClients = rc.consultantDistrictsRepository.districtsForConsultant(userID);
// schools managed by consultant
if (consultClients != null)
{
consultantSchoolList = (from c in rc.clientsRepository.Clients
where (consultClients.Contains(c.cdsCode.Substring(0, 7)))
select c.cdsCode).ToList();
}
on the "consultantSchoolList = " line.
This is an MVC project and I am using a context object that is stored in the HttpContext.Current object. Each repository has a private variable that stores the context object, but each one should point to the same object in the HttpContext.Current Items collection. Would this be considered two different contexts even though they point to the same thing?
Stepping through the code in the debugger shows that the context objects for the two repositories, consultantDistrictsRepository and clientsRepository, do point to the same object in the HttpContext.Current object.
UPDATE Here's how I define the context objects in each repository:
private SchedulerContext context;
public EFConsultantDistricts()
{
context = ContextHelper.GetContext();
}
and GetContext is as follows:
public static SchedulerContext GetContext()
{
if (!HttpContext.Current.Items.Contains("_db_context"))
{
HttpContext.Current.Items.Add("_db_context", new SchedulerContext());
}
return (SchedulerContext)HttpContext.Current.Items["_db_context"];
}
I found the problem -- I was caching the frequently-requested clients list in a Session variable in the Clients repository:
if (HttpContext.Current.Session["clientList"] == null)
{
HttpContext.Current.Session["clientList"] = from c in context.Clients
where (c.Year == fiscalYear)
select c;
}
return (IQueryable<Client>)HttpContext.Current.Session["clientList"];
Since the Session object persists over requests, I guess it was using a previous context object. I thought the client list would be separated from the context object, but I guess not if I'm using IQueryable.
I hate to hit the database every time for this, but I guess I have no choice ... at least for the moment until I get everything straightened out.