I'm using ASP.NET Zero. Project Version: 5.1.0 and .NET Core 2.0 template. I'm trying to enable Entity History for my entity so that I can see the deleted and old column values for the table.
Entity class:
[Table("TestingEntity")]
[Audited]
public class TestingEntity : AuditedEntity , IMayHaveTenant
{
public int? TenantId { get; set; }
public virtual string Code { get; set; }
}
ApplicationModule class:
public class MyCompanyApplicationModule : AbpModule
{
public override void PreInitialize()
{
// ...
Configuration.EntityHistory.IsEnabledForAnonymousUsers = true;
Configuration.EntityHistory.Selectors.Add(new NamedTypeSelector("Abp.AuditedEntities", type => typeof(IAudited).IsAssignableFrom(type)));
}
// ...
}
Running the following queries give no results.
SELECT * FROM [AbpEntityChangeSets]
SELECT * FROM [AbpEntityPropertyChanges]
SELECT * from [AbpEntityChanges]
Reference: https://aspnetboilerplate.com/Pages/Documents/Entity-History
Update
It is not giving proper results when I'm deleting an entity item.
It's inserting records for each property with old and new values the same in [AbpEntityPropertyChanges] table.
And there is no clear information that this entity item is deleted, its deletion time, and DeletedBy.
Is this due to using AuditedEntity in my entity class? I'm using hard delete, so I thought not to add these columns to the table: is deleted, its deletion time, and DeletedBy.
Entity History is disabled in ASP.NET Zero. You can enable it:
Configuration.EntityHistory.IsEnabled = true;
Update
It is not giving proper results when I'm deleting an entity item.
It's inserting records for each property with old and new values the same in [AbpEntityPropertyChanges] table.
That has been resolved in PR #2977, which will be released with ABP v3.5.
And there is no clear information that this entity item is deleted, its deletion time, and DeletedBy.
Is this due to using AuditedEntity in my entity class? I'm using hard delete, so I thought not to add these columns to the table: is deleted, its deletion time, and DeletedBy.
You won't find those in AbpEntityPropertyChanges table, since those aren't property changes.
information that this entity was deleted: EntityChange.ChangeType
its deletion time: EntityChangeSet.CreationTime
DeletedBy: EntityChangeSet.UserId
Additional information
relationship between AbpEntityChangeSets and AbpEntityChanges tables: EntityChange.cs
public class EntityChange : Entity<long>, IMayHaveTenant
{
/// <summary>
/// Gets/sets change set id, used to group entity changes.
/// </summary>
public virtual long EntityChangeSetId { get; set; }
// ...
}
possible values of EntityChange.ChangeType: EntityChangeType.cs
public enum EntityChangeType : byte
{
Created = 0,
Updated = 1,
Deleted = 2
}
Do we have a plan to add UI for this feature? So that we can see Entity History from UI.
This has been added in ASP.NET Zero 5.4.0.
I have solved the issue by doing the below change in file ProjectName.EntityFrameworkCore\EntityFrameworkCore\ProjectNameEntityFrameworkCoreModule.cs by setting the following value to true, You need to enable Entity History.
Configuration.EntityHistory.IsEnabled = true;
You can refer https://github.com/aspnetzero/aspnet-zero-core/issues/818#issuecomment-365250173.
I've got an object that has a key stored as a GUID as well as a friendlyID, like this:
public class Job {
[Key]
public Guid Id { get; set; }
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int FriendlyId { get; set; }
public string Description { get; set; }
}
However when I try to update description using my update method:
public void Update(Job job, Job jobParam) {
if (job == null) {
throw new AppException("Job does not exist");
}
//Update job properties
job.Description = jobParam.Description;
_context.Job.Update(job);
_context.SaveChanges();
}
I get an error stating:
System.Data.SqlClient.SqlException: Cannot update identity column
'FriendlyId'
I've made sure that the correct object is trying to be updated, but I can't understand why friendlyID would try to get updated when it has not been changed. When looking online I can see that there was a bug in EF core 1.1 that would cause this issue to occur, but nothing about 2.0 or about a value that isn't a key.
The exact behavior of the generated properties in EF Core is still in a process of tweaking. EF Core 2.0 introduced two new property metadata properties - BeforeSaveBehavior and AfterSaveBehavior. There is no data annotation/fluent API for setting them and by default they are implied from value generating strategy and whether the property is part of the key. At the same time they affect the behavior of the tracking operations.
The problem here is that for identity columns (i.e. ValueGeneratedOnAdd) which are not part of a key, the AfterSaveBehavior is Save, which in turn makes Update method to mark them as modified, which in turn generates wrong UPDATE command.
To fix that, you have to set the AfterSaveBehavior like this (inside OnModelCreating override):
modelBuilder.Entity<Job>()
.Property(e => e.FriendlyId)
.ValueGeneratedOnAdd()
.Metadata.AfterSaveBehavior = PropertySaveBehavior.Throw; // <--
Update: In EF Core 3.0+ many metadata properties have been replaced with Get/Set methods, so just use the corresponding method:
.Metadata.SetAfterSaveBehavior(PropertySaveBehavior.Throw);
I have a simple code in Entity Framework (EF) v4.1 code first:
PasmISOContext db = new PasmISOContext();
var user = new User();
user.CreationDate = DateTime.Now;
user.LastActivityDate = DateTime.Now;
user.LastLoginDate = DateTime.Now;
db.Users.Add(user);
db.SaveChanges();
user.Avatar = new Avatar() { Link = new Uri("http://myUrl/%2E%2E/%2E%2E") };
db.SaveChanges();
db.Users.Add(new User() { Avatar = new Avatar() { Link = new Uri("http://myUrl/%2E%2E/%2E%2E") } });
db.SaveChanges();
The problem is that I get an error
An error occurred while saving entities that do not expose foreign key
properties for their relationships. The EntityEntries property will
return null because a single entity cannot be identified as the source
of the exception. Handling of exceptions while saving can be made
easier by exposing foreign key properties in your entity types. See
the InnerException for details.
at
db.Users.Add(new User() { Avatar = new Avatar() { Link = new Uri("http://myUrl/%2E%2E/%2E%2E") } });
db.SaveChanges();
I don't understand why the similar operation works. Is there something wrong with my model, or with ef-code-first?
public class Avatar
{
[Key]
public int Id { get; set; }
[Required]
public string LinkInString { get; set; }
[NotMapped]
public Uri Link
{
get { return new Uri(LinkInString); }
set { LinkInString = value.AbsoluteUri; }
}
}
public class User
{
[Key]
public int Id { get; set; }
public string UserName { get; set; }
public string Email { get; set; }
public string Password { get; set; }
public Avatar Avatar { get; set; }
public virtual ICollection<Question> Questions { get; set; }
public virtual ICollection<Achievement> Achievements { get; set; }
public DateTime CreationDate { get; set; }
public DateTime LastLoginDate { get; set; }
public DateTime LastActivityDate { get; set; }
}
For those of you who would still have this error with all keys properly defined, have a look at your entities and make sure you don't leave a datetime field with a null value.
This error message can be thrown for any kind of reason. The 'InnerException' property (or its InnerException, or the InnerException of that, etc) contains the actual primary cause of the problem.
It would of course be useful to know something about where the problem occurred - which object(s) in the unit of work is causing the problem? The exception message would normally tell you in the 'EntityEntries' property, but in this case, for some reason, that can't be done. This diagnostic complication - of the 'EntityEntries' property being empty - is apparently because some Entities 'do not expose foreign key properties for their relationships.'
Even if the OP gets the error because of failing to initialize DateTimes for the second instance of User, they get the diagnostic complication - 'EntityEntries' being empty, and a confusing top-level message ... because one of their Entity's doesn't 'expose foreign key properties'. To fix this, Avatar should have a public virtual ICollection<User> Users { get; set; } property defined.
The issue was resolved by adding an FK property.
In my case the following situation was giving me the same Exception:
Imagine a code first EF model where you have a Garage entity that has a collection of Car entities. I needed to remove a car from the garage so I ended up with code that looked like this:
garageEntity.Cars.Remove(carEntity);
Instead, it should've been looked like this:
context.Cars.Remove(carEntity);
Just for others who might have similar problems. I had the same error, but for a different reason. In one of the child objects I defined the [Key] as being a value which was the same for different saves. A stupid mistake on my part, but the error message does not instantly lead you to the problem.
In my case the exeception was thrown because EF had created a migration incorrectly.
It missed setting the identity: true on the second table. So go into the migrations which created the relevant tables and check if it missed to add identity.
CreateTable(
"dbo.LogEmailAddressStats",
c => new
{
Id = c.Int(nullable: false, identity: true),
EmailAddress = c.String(),
})
.PrimaryKey(t => t.Id);
CreateTable(
"dbo.LogEmailAddressStatsFails",
c => new
{
Id = c.Int(nullable: false), // EF missed to set identity: true!!
Timestamp = c.DateTime(nullable: false),
})
.PrimaryKey(t => t.Id)
.ForeignKey("dbo.LogEmailAddressStats", t => t.Id)
.Index(t => t.Id);
An Id column should have identity (i.e. auto-incrementing!) so this must be a EF bug.
You could add identity manually with SQL directly to the database but I prefer using Entity Framework.
If you run in to the same problem I see two easy solutions:
Alt 1
reverse the incorrectly created migration with
update-database -target:{insert the name of the previous migration}
Then add the identity: true manually to the migration code and then update-database again.
Alt 2
you create a new migration that adds identity. If you have no changes in the models and you run
add-migration identity_fix
it will create an empty migration. Then just add this
public partial class identity_fix : DbMigration
{
public override void Up()
{
AlterColumn("dbo.LogEmailAddressStatsFails", "Id", c => c.Int(nullable: false, identity: true));
}
public override void Down()
{
AlterColumn("dbo.LogEmailAddressStatsFails", "Id", c => c.Int(nullable: false));
}
}
This problem can also arise from reversed key declarations. If you're using fluent to configure the relationship, make sure the left and right keys are mapped to the correct entity.
I hade same probleme. in my case, it was due to datetime field with a null value. I had to passe a value to datetime and evrythings went fine
Another answer:
I used this:
public List<EdiSegment> EdiSegments { get; set; }
instead of this:
public virtual ICollection<EdiSegment> EdiSegments { get; set; }
and got the error message noted above.
I had the same error and in my case the problem was that I added a relationship object which had already been loaded "AsNoTracking". I had to reload the relation property.
BTW, Some suggest using "Attach" for relations that already exist in db, I haven't tried that option though.
In my case, the problem was that I renamed a column improperly, so the migration made two columns, one called "TeamId" and one called "TeamID". C# cares, SQL doesn't.
Yet another different case here.
A query was cast to a list and while doing that, it created entities by their constructor for comparison in the linq expression right after the ToList(). This created entities that gotten into the deleted state after the linq expression finished.
However! There was a small adjustment that created another entity in the constructor, so that this new entity got linked to an entity that was marked as Deleted.
Some code to illustrate:
query.Except(_context.MyEntitySetSet()
.Include(b => b.SomeEntity)
.Where(p => Condition)
.ToList() // This right here calls the constructor for the remaining entities after the where
.Where(p => p.Collection.First(b => Condition).Value == 0)
.ToList();
The constructor of MyEntity:
public partial class MyEntity
{
protected MyEntity()
{
// This makes the entities connected though, this instance of MyEntity will be deleted afterwards, the instance of MyEntityResult will not.
MyEntityResult = new MyEntityResult(this);
}
}
My solution was to make sure the entire expression was done inside the IQueryable so that there won't be any objects created.
I'm not entirely sure that it's going to help in your case because I'm setting up my tables using Fluent API, however, as far I can tell, the issue arises regardless whether the schema is set up using data annotations (attributes) or Fluent API (configuration).
There seems to be a bug in EF (v. 6.1.3) as it omits certain changes to the schema when updating the DB to the next migration. The quickest route around it is (during the development stage) to remove all the tables from the DB and runt migrations from init stage again.
If you're already in production, the quickest solution I've found was to manually change the schema in the DB or, if you want to have version control of the changes, manually manipulate the methods Up() and Down() in your migration.
Today I faced this issue and tried the possible solutions posted above but none of them helped me. I had UnitOfWork pattern implemented and system was committing the data in last after adding all the records.
In my case system was combining the two models and querying the DB
Invalid object name 'dbo.RoleModelUserModel'.
where these were two different models actually.
I fixed this by reordering the insert statements and adding the parent entity first. In this case added the user first and issue resolved.
After a bit of investigation I found that whilst .Net supports a minimum date (DateTime.MinValue) of 01/01/0001 00:00:00 and a maximum (DateTime.MaxValue) of 31/12/9999 23:59:59 in SQL Server Compact Edition minimum date is 01/01/1753 00:00:00.
When I entered a date greater than 01/01/1753 00:00:00, this error disappeared.
Is your application or website being accessed from some third party application when this error is coming? If yes, then please check the access rights of the account which is sending the request to your application.
In our case, it was ServiceNow MID server service which was the culprit. It is a Windows service. If you want to know more about it then please read this link. So basically, you need to check two things:
Under the context of which account the calling service should run to access your application?
What all access rights are needed for the service's log on account to do all allowed operations in your application?
As per this article of ServiceNow we had to give Log on as a service right to the MID Server service's log on account. You can do it via in Local Security Policies console (Refer screenshot).
After we gave the proper access rights to the logon account, the Entity Framework issue went away. Please remember that the access rights and the log on account to be used will be specific to your application.
Problem
I have a situation whereby I need to use Entity Framework 6, Code First, with a legacy database structure which cannot be changed. The database has a very generic table which stores text based data alongside some non key data which can be used to relate the record back to another table.
To illustrate:
Assume the Notes table has a model as follows:
[Table("Notes")]
public class Notes
{
[Key]
public int RecordId { get; set; }
[Required]
public string RelatedTableName { get; set; }
[Required]
public int RelatedTableRecordId { get; set; }
[Required]
public string NotesText { get; set; }
}
I then have another model which could look like so:
[Table("Drivers")]
public class Drivers
{
[Key]
public int RecordId { get; set; }
[Required]
public string DriverName { get; set; }
public ICollection<Notes> DriverNotes { get; private set; }
}
There is no foreign key which links the tables. The Drivers table is linked to the Notes table by way of the RelatedTableName and RelatedTableRecordId fields.
I do not have a problem reading data from the database and hydrating the models using entity framework.
The problem I have is that I want to be able to save a new Driver and its newly created Notes in one transaction and have the RelatedTableRecordId field set to the primary key of the Driver.
If a foreign key existed entity framework would know to back fill the property but in this case it doesn't know about the relationship.
Key Points
Database Structure must not change.
Must use Entity Framework 6 Code First
Must be able to use an Execution Strategy.
Require a relationship between non key fields.
Need to be able to persist all data in a single transaction.
What I've Tried
I had a similar issue with Audit type data and solved it by doing something similar to the following (note that this is very pseudo here):
public override int SaveChanges()
{
int changes = 0;
//Disable the current execution strategy as the default ones do not support user instantiated transactions.
this.ContextConfiguration.SuspendExecutionStrategy();
try
{
//Wrap a whole transaction inside an execution strategy so that auditing can be combined with regular saving of changes.
this.ExecutionStrategy.Execute(
() =>
{
using (var transaction = this.Database.BeginTransaction())
{
//Reset the change count so that it doesn't increase each time the transaction fails.
changes = 0;
//Remove any audit records created by previous failed transactions.
this.AuditTableChanges.Local.Clear();
//Evaluate the change tracker to identify entities which will potentially require an audit trail.
var insertedEntities = this.ChangeTracker.Entries().Where(entryEntity => entryEntity.State == EntityState.Added).ToList();
//Save all changes to get identities.
changes = base.SaveChanges();
//Create the audit trail for inserted entities. This step must occur after the initial call to SaveChanges() so that the identities are set.
foreach (DbEntityEntry entryEntity in insertedEntities)
{
//For each inserted record, get the audit record entries and add them
foreach (AuditTableChange auditTableChange in GetAuditRecords(entryEntity, AuditTableChangeType.Insert).Result)
this.AuditTableChanges.Add(auditTableChange);
}
//Save the audit trail for inserted entities.
changes += base.SaveChanges();
//Commit all changes to the database
transaction.Commit();
}
});
}
finally
{
//Re-enable the execution strategy so that other calls can benefit from the retry policy.
this.ContextConfiguration.UnSuspendExecutionStrategy();
}
return changes;
}
This worked fine for the Audit data as the implementation was hidden away in the framework. I do not want my development team to have to do all of the above each time they persist records.
In its simplistic form this is as much as I'd want people to be doing:
public void CreateDriver()
{
using (MyContext context = new MyContext())
{
Drivers driver = new Drivers();
driver.DriverName = "Joe Bloggs";
Notes driverNote = new Notes();
driverNote.RelatedTableName = "Drivers";
driverNote.NotesText = "Some very long text";
driver.DriverNotes.Add(driverNote);
context.Drivers.Add(driver);
context.SaveChanges();
}
}
In a way I want a foreign key which exists in code but not in the database so that entity framework knows to fill in the RelatedTableRecordId field. I've read some articles on hacking the EDMX but this project is purely Code First only.
There are older questions on stack overflow which are similar but relate to older versions of entity framework and don't help much or have as much detail as the above.
I'm hoping that someone may have experienced a similar problem and has an answer which may involve perhaps some custom mapping/metadata or some overrides to entity framework logic.
Any help would be appreciated.
Thanks,
Greg
There are a few questions out there on this topic, but my question is very specific to true self referencing. All the examples for other questions are circular references and that doesn't help me in this case.
Lets say I have this model:
public class User
{
[Key]
public int Id { get; set; }
...
public int CreatedByUserId { get; set; }
}
and this map:
public class UserMap : EntityTypeConfiguration<User>
{
public UserMap()
{
this.HasRequired(a => a.CreatedByUser)
.WithMany()
.HasForeignKey(u => u.CreatedByUserId);
}
}
After migrations generates a database with this code I can manually add a User in SQL Management Studio with Id = 1, and CreatedByUserId = 1 so that tells me that self references like this can work.
However when using EF to create a user, I run into a "unable to determine a valid ordering for dependent operations" issue. There are a lot of questions on the matter that involve a new entity that refers another new entity that has a foreign key on the first entity, which is a circular reference. The solution in those cases is either save one of entities first or to have a nullable id on the circular entity foreign key. I can not do either of those because the first would be impossible and the second is a external constraint that I cannot have nullable ids.
So, seeing how I can achieve this by adding a entry manually I can assume it's a limitation of EF5. What are the work arounds?
You can still satisfy your interface and do the save first then set method by adding another property to act as a nullable backer for CreatedByUserId:
public class User : ICreatable
{
[Key]
public int Id { get; set; }
...
public int CreatedByUserId
{
get
{
if (!_CreatedByUserId.HasValue)
//throw new exception, something went wrong.
return _CreatedByUserId;
}
set
{
_CreatedByUserId = value;
}
}
int? _CreatedByUserId { get; set; }
}
You may want to rethink the possibility that a user can create him or herself...
However if you really want to do this then there is a solution. Your main problem is the fact that your column is an IDENTITY column which means that EF doesn't specify the Id, SQL server is giving each row an auto-incrementing Id. Any value you set as the Id is ignored. You don't necessarily know when executing the INSERT what the next Id is going to be so you can't create a reference to a row that doesn't exist yet.
Change your mapping code to something like the following:
this.Property(x => x.Id)
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);
this.HasRequired(x => x.CreatedByUser)
.WithMany();
You don't need to specify the foreign key if the name pattern matches (eg. CreatedByUser and CreatedByUserId).
Now when you insert a User you can specify the Id and the CreatedById. Although note that you must now always specify the Id to insert a new User. This is common practice if you are using GUIDs as Ids because you can just generate a new GUID without having to first query for the next "available" Id before creating a new object.