I am using Entity Framework Code First - I am getting the following message in deleting any of the tables data - like CaseNov, ViolationsNov and ViolationTypeNov are three tables which are to handle many to many relationships between Case-Nov, Violation-Nov and ViolationType-Nov, I am getting error messages even if I trying to delete the detailed tables like: CaseNov, ViolationsNov, ViolationTypeNov or row directly from NOV table, I am getting the similar type of message - any help please? I am using Entity Framework Code First for deleting it
The operation failed: The relationship could not be changed because one or more of the foreign-key
properties is non-nullable. When a change is made to a relationship, the related foreign-key
property is set to a null value. If the foreign-key does not support null values, a new relationship
must be defined, the foreign-key property must be assigned another non-null value or the unrelated
object must be deleted.
And here is my Code for delete operation:
public bool Delete(NOV nov, bool performCommit = true)
{
System.Data.Entity.DbContextTransaction dbOperation = null;
if (performCommit)
dbOperation = UnitOfWork.BeginTransaction();
try
{
//deleting all OneToMany references to NOV
List<ViolationTypeNOV> novRels = UnitOfWork.ViolationTypeNOVRepository
.GetAll().Where(x => x.NOVId == nov.NOVId).ToList();
foreach (ViolationTypeNOV o in novRels)
{
nov.ViolationTypeNOVs.Remove(o);
this.UnitOfWork.ViolationTypeNOVRepository.Delete(o.ViolationTypeNOVId);
}
novRels.RemoveAll(x => x.NOVId == nov.NOVId);
List<ViolationNOV> violationNOVs = UnitOfWork.ViolationNOVRepository
.GetAll().Where(x => x.NOVId == nov.NOVId).ToList();
foreach (ViolationNOV o in violationNOVs)
{
nov.ViolationNOVs.Remove(o);
this.UnitOfWork.ViolationNOVRepository.Delete(o.ViolationNOVId);
}
violationNOVs.RemoveAll(x => x.NOVId == nov.NOVId);
List<CaseNOV> caseNOVs = UnitOfWork.CaseNOVRepository
.GetAll().Where(x => x.NOVId == nov.NOVId).ToList();
foreach (CaseNOV o in caseNOVs)
{
nov.CaseNOVs.Remove(o);
this.UnitOfWork.CaseNOVRepository.Delete(o.CaseNOVId);
}
caseNOVs.RemoveAll(x => x.NOVId == nov.NOVId);
UnitOfWork.NOVRepository.Delete(nov.NOVId);
if (dbOperation != null)
dbOperation.Commit();
LogHandler.LogInfo(2521, "Deleted NOV " + nov.NOVNumber);
return true;
}
catch (Exception ex)
{
LogHandler.LogError(2523, "Commit Fail in NOV Delete", ex);
if (dbOperation != null)
dbOperation.Rollback();
throw ex;
}
}
Unit of Work Code:
public DataAccessUnitOfWork UnitOfWork { get; set; }
public RoleManager<ApplicationRole> RoleManager { get; set; }
public UserManager<ApplicationUser> UserManager { get; set; }
public ApplicationUser CurrentUser { get; set; }
public DomainLogicManager(DataAccessUnitOfWork unitOfWork)
{
this.UnitOfWork = unitOfWork;
this.RoleManager = new RoleManager<ApplicationRole>(new RoleStore<ApplicationRole>(UnitOfWork.Context));
this.UserManager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(UnitOfWork.Context));
}
Delete method in one of the repository classes is as follows:
public bool Delete(IdT id)
{
T item = this.DbSet.Find(id);
var entry = this.Context.Entry(item);
entry.State = EntityState.Deleted;
this.DbSet.Attach(item);
this.DbSet.Remove(item);
this.Context.SaveChanges();
BuildMetaData(item, false, false);
return true;
}
Related
I am getting changed entity from fronted, mapping it on backend side and simply want to update it in database.
Update is performing like this:
[HttpPut("{id}")]
public IActionResult Update(string id, [FromBody]Worker worker)
{
using (var dbContext= new MyDbContext())
{
dbContext.ChangeTracker.QueryTrackingBehavior = QueryTrackingBehavior.NoTracking;
var entity = dbContext.Workers.FirstOrDefault(r => r.Id == worker.Id);
if (entity == null) return BadRequest();
dbContext.Workers.Update(worker);
dbContext.SaveChanges();
return Ok();
}}
Before this action, i am getting the list of users and sending it to frontend.
Although I set QueryTrackingBehavior to NoTracking, i am getting exception:
System.InvalidOperationException: 'The instance of entity type 'Contract' cannot be tracked because another instance with the key value 'Id:4' is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached.'
Where Contract is related entity for Worker which is updated...
Any idea what i am doing wrong here?
UPDATE:
Worker - Contract relation:
public class Worker: IId
{
public int Id { get; set; }
public ICollection<Contract> Contracts{ get; set; }
}
public class Contract: IId
{
public int Id { get; set; }
public int WorkerId { get; set; }
public Worker Worker { get; set; }
}
Okay! got the problem in your code. You didn't map the updated entity to the existing entity that you pulled from the database. You have to map the updated entity to the existing entity. To do so you can use AutoMapper or explicit mapping as follows:
You can solve the problem as follows:
[HttpPut("{id}")]
public IActionResult Update(string id, [FromBody]Worker worker)
{
using (var dbContext= new MyDbContext())
{
var entityToBeUpdated = dbContext.Workers.AsNoTracking().FirstOrDefault(r => r.Id == worker.Id);
if (entity == null) return BadRequest();
entityToBeUpdated.Property1 = worker.Property1;
entityToBeUpdated.Property2 = worker.Property2;
// Do the same for the other changed properties as well
dbContext.Workers.Update(entityToBeUpdated);
dbContext.SaveChanges();
return Ok();
}
}
Alternatively you can try as follows:
[HttpPut("{id}")]
public IActionResult Update(string id, [FromBody]Worker worker)
{
using (var dbContext= new MyDbContext())
{
var entityToBeUpdated = dbContext.Workers.FirstOrDefault(r => r.Id == worker.Id);
if (entity == null) return BadRequest();
entityToBeUpdated.Property1 = worker.Property1;
entityToBeUpdated.Property2 = worker.Property2;
// Do the same for the other changed properties as well.
dbContext.SaveChanges();
return Ok();
}
}
I'm writing an MVC app in ASP.NET with the help of EF and I'm trying to seed my database. I have the following model:
public class Team
{
[ScaffoldColumn(false)]
public int Id { get; set; }
[ForeignKey("ParentTeam")]
public int? ParentTeamId { get; set; }
[Required(ErrorMessage = "Cannot create a Team without a name")]
[Index(IsUnique = true)]
[MaxLength(30)]
public string Name { get; set; }
public IEnumerable<string> Members { get; set; }
public virtual Team ParentTeam { get; set; }
public Team() { }
public Team(string name)
{
Name = name;
}
}
My migration says:
var team = new Team("Admin");
var team2 = new Team("Test Team");
var team3 = new Team("Test Team 2");
context.Teams.AddOrUpdate(t => t.Name, team, team2, team3);
context.SaveChanges();
And then, when I run Update-Database, I get:
System.Data.SqlClient.SqlException: Cannot insert duplicate key row in
object 'dbo.Teams' with unique index 'IX_Name'. The duplicate key
value is (Admin).
It's a little confusing - I thought I told AddOrUpdate to identify rows to update by their names, but this does not happen. I cannot add Name to Team's primary key, because it has a self-referencing foreign key (I could add ParentTeamName as a property, but I don't feel that it should be necessary). Am I misunderstanding the behaviour of AddOrUpdate? Did I specify the condition wrong?
I had the exact same reason. In my case, it was working fine, until I needed to use an Unique Index, when it broke.
My solution was to create a CustomAddOrUpdate method where I try to find the existing instance first based on a Where predicate. If I find it, I just update the properties and if not, it is added to the context.
However, before updating the instance, I had to copy the key values from the original instance to the new instance, to avoid an EF exception telling you cannot change key properties.
Here are the code snippets:
1) First the code in the context class
public void CustomAddOrUpdate<TEntity>(Expression<Func<TEntity, bool>> whereExpression, TEntity entity) where TEntity : class
{
var entitySet = this.EntitySet<TEntity>();
var foundInstance = entitySet.Where(whereExpression).FirstOrDefault();
if (foundInstance != null)
{
CopyKeyProperties<TEntity>(foundInstance, entity);
Entry(foundInstance).CurrentValues.SetValues(entity);
}
else
{
entitySet.Add(entity);
}
}
private void CopyKeyProperties<TEntity>(TEntity source, TEntity target) where TEntity : class
{
string[] keys = this.GetKeyNames<TEntity>();
foreach(var keyName in keys)
{
Entry(target).Property(keyName).CurrentValue = Entry(source).Property(keyName).CurrentValue;
}
}
2) Then on my seed code:
var entityList = new List<MyExempleEntity>()
{
new MyExampleEntity { Prop1 = "a p1", Prop2 = "a p2" },
new MyExampleEntity { Prop1 = "b p1", Prop2 = "b p2" },
new MyExampleEntity { Prop1 = "c p1", Prop2 = "c p2" },
}
foreach(var item in entityList)
{
context.CustomAddOrUpdate<MyExampleEntity>(x => x.Prop1 == item.Prop1 && x.Prop2 == item.Prop2, item);
}
context.SaveChanges()
3) And to wrap up, here you are the code to get the KeyProperties from an entity:
using System.Data.Entity.Core.Metadata.Edm;
using System.Data.Entity.Infrastructure;
using System.Linq;
namespace System.Data.Entity
{
public static class DbContextExtensions
{
public static string[] GetKeyNames<TEntity>(this DbContext context)
where TEntity : class
{
return context.GetKeyNames(typeof(TEntity));
}
public static string[] GetKeyNames(this DbContext context, Type entityType)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
MetadataWorkspace metadata = ((IObjectContextAdapter)context).ObjectContext.MetadataWorkspace;
// Get the mapping between CLR types and metadata OSpace
var objectItemCollection = ((ObjectItemCollection)metadata.GetItemCollection(DataSpace.OSpace));
// Get metadata for given CLR type
var entityMetadata = metadata
.GetItems<EntityType>(DataSpace.OSpace)
.Single(e => objectItemCollection.GetClrType(e) == entityType);
return entityMetadata.KeyProperties.Select(p => p.Name).ToArray();
}
}
}
The above code was grabbed from this blog:
https://romiller.com/2014/10/07/ef6-1-getting-key-properties-for-an-entity/
I started a db schema using EF and ran into multiple issues when tring to mannually modify the CLR's and/or db tables. First was a "Employee_ID" column that EF placed in a table. I deleted it, the dbo.EdmMetaData and the dbo.__MigrationHistory tables and fumbled through the run-time errors that insued. Now, I'm grapling with the following error:
A dependent property in a ReferentialConstraint is mapped to a store-generated column. Column: 'EmployeeID'.
My implementation uses a TimeCardEntity CLR that has 3 computed columns. These columns just so happens to map to another table's Primary Key. This other table is EmployeeRecord.
GOAL) I don't WANT EF to auto map thse 3 columns. I intend to fill them myself due to the complications EF offers, but I can't tell EF to stop creating navigation relationships and/or referential constraints.
Point #1) I have a EmployeeRecord table that has a Guid ID primary key, it maps to CLR class EmployeeRecord
Point #2) I have a TimeCardEntity table that has has 3 computed columns called EmployeeID, ManagerID, DivisionManagerID that relate back to EmployeeRecord. All are NULL declared but EmployeeID is required, obviously, because you can't have a time card without declaring the employee. The ManagerID and DivisionManagerID get filled later.
Point #3) Please don't ask me "Why are these computed?", because there is a reason. I alos feel it is illrelevant to the issue. In short, computed EmployeeID's (whether employee, manager or division mananger), are stored in an xml property with the data of approval and signature of employee - which provides non reputiation.
Point #4) I have 3 stored functions called fxGetEmployeeID(xml), fxGetManagerID(xml), and getDivisonManagerID(xml). Each of these are used in the computed columns EmployeeID, ManagerID and DivisionManagerID respectively.
Here is the class declarations simplified for brevity:
public enum TimeCardEmployeeTypeEnum {
Employee,
Manager,
DivisionManager
}
[DataContract]
[Serializable]
[Table("EmployeeRecord", Schema = "TimeCard")]
public class EmployeeRecord {
#region Exposed Propert(y|ies)
[DataMember]
public Guid ID { get; set; }
/// <summary>
/// Customers internal company employee ID. Can be null, SSN, last 4, or what ever...
/// I included it just in case it was part of my pains...
/// </summary>
[CustomValidation(typeof(ModelValidator), "EmployeeRecord_EmployeeID", ErrorMessage = "Employee ID is not valid.")]
public string EmployeeID { get; set; }
#endregion
}
[DataContract]
[Serializable]
[Table("TimeCardEntry", Schema = "TimeCard")]
public class TimeCardEntry {
#region Member Field(s)
[NonSerialized]
XDocument m_TimeEntries;
#endregion
#region Con/Destructor(s)
public TimeCardEntry() {
this.m_TimeEntries = "<root />".ToXDocument();
}
public TimeCardEntry(Guid employeeID) {
if (employeeID == Guid.Empty)
throw new ArgumentNullException("employeeID");
this.m_TimeEntries = "<root />".ToXDocument();
this.EmployeeID = employeeID;
}
#endregion
#region Exposed Propert(y|ies)
[NotMapped]
[IgnoreDataMember]
public XDocument TimeEntries {
get {
if (this.m_TimeEntries == null) {
if (!string.IsNullOrEmpty(this.TimeEntriesXml))
this.m_TimeEntries = this.TimeEntriesXml.ToXDocument();
}
return this.m_TimeEntries;
}
set {
this.m_TimeEntries = value;
if (this.m_TimeEntries != null)
this.TimeEntriesXml = this.m_TimeEntries.ToString();
else
this.TimeEntriesXml = null;
this.OnPropertyChanged("TimeEntriesXml");
this.OnPropertyChanged("TimeEntries");
}
}
[DataMember]
[EditorBrowsable(EditorBrowsableState.Never)]
[Required]
public string TimeEntriesXml {
get {
if (this.m_TimeEntries == null)
return null;
return this.m_TimeEntries.ToString();
}
set {
this.m_TimeEntries = value.ToXDocument();
this.OnPropertyChanged("TimeEntriesXml");
this.OnPropertyChanged("TimeEntries");
}
}
[IgnoreDataMember]
[DatabaseGenerated(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Computed)]
public Guid? EmployeeID {
get {
var attribute = this.m_TimeEntries.Root.Attribute("EmployeeID");
if (attribute != null)
return (Guid)attribute;
return null;
}
set {
if (this.ValidateSignature(TimeCardEmployeeTypeEnum.Manager))
throw new ArgumentException("Property cannot be changed once the manager signature has been set.", "EmployeeID");
if (value != null && value.Value != Guid.Empty)
this.m_TimeEntries.Root.SetAttributeValue("EmployeeID", value);
else {
var attribute = this.m_TimeEntries.Root.Attribute("EmployeeID");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("EmployeeID");
}
}
public virtual EmployeeRecord Employee { get; set; }
[NotMapped]
[IgnoreDataMember]
public DateTime? EmployeeApprovalDate {
get {
var attribute = this.m_TimeEntries.Root.Attribute("EmployeeApprovalDate");
if (attribute != null)
return (DateTime)attribute;
return null;
}
set {
if (this.ValidateSignature(TimeCardEmployeeTypeEnum.Manager))
throw new ArgumentException("Property cannot be changed once the manager signature has been set.", "EmployeeApprovalDate");
if (value.HasValue)
this.m_TimeEntries.Root.SetAttributeValue("EmployeeApprovalDate", value);
else {
var attribute = this.m_TimeEntries.Root.Attribute("EmployeeApprovalDate");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("EmployeeApprovalDate");
}
}
[NotMapped]
[IgnoreDataMember]
public byte[] EmployeeSignature {
get {
var attribute = this.m_TimeEntries.Root.Attribute("EmployeeSignature");
if (attribute != null)
return Convert.FromBase64String((string)attribute);
return null;
}
set {
if (this.ValidateSignature(TimeCardEmployeeTypeEnum.Manager))
throw new ArgumentException("Property cannot be changed once the manager signature has been set.", "EmployeeSignature");
if (value != null) {
if (value.Length > 1024)
throw new ArgumentException("Signature cannot be larger than 1KB.", "EmployeeSignature");
this.m_TimeEntries.Root.SetAttributeValue("EmployeeSignature", Convert.ToBase64String(value));
} else {
var attribute = this.m_TimeEntries.Root.Attribute("EmployeeApprovalDate");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("EmployeeSignature");
}
}
[IgnoreDataMember]
[DatabaseGenerated(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Computed)]
public Guid? ManagerID {
get {
var attribute = this.m_TimeEntries.Root.Attribute("ManagerID");
if (attribute != null)
return (Guid)attribute;
return null;
}
set {
if (this.ValidateSignature(TimeCardEmployeeTypeEnum.DivisionManager))
throw new ArgumentException("Property cannot be changed once the division manager signature has been set.", "ManagerID");
if (value.HasValue) {
if (value.Value == Guid.Empty)
throw new ArgumentNullException("ManagerID");
this.m_TimeEntries.Root.SetAttributeValue("ManagerID", value);
} else {
var attribute = this.m_TimeEntries.Root.Attribute("ManagerID");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("ManagerID");
}
}
public virtual EmployeeRecord Manager { get; set; }
[NotMapped]
[IgnoreDataMember]
public DateTime? ManagerApprovalDate {
get {
var attribute = this.m_TimeEntries.Root.Attribute("ManagerApprovalDate");
if (attribute != null)
return (DateTime)attribute;
return null;
}
set {
if (this.ValidateSignature(TimeCardEmployeeTypeEnum.DivisionManager))
throw new ArgumentException("Property cannot be changed once the division manager signature has been set.", "ManagerApprovalDate");
if (value.HasValue)
this.m_TimeEntries.Root.SetAttributeValue("ManagerApprovalDate", value);
else {
var attribute = this.m_TimeEntries.Root.Attribute("ManagerApprovalDate");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("ManagerApprovalDate");
}
}
[NotMapped]
[IgnoreDataMember]
public byte[] ManagerSignature {
get {
var attribute = this.m_TimeEntries.Root.Attribute("ManagerSignature");
if (attribute != null)
return Convert.FromBase64String((string)attribute);
return null;
}
set {
if (this.ValidateSignature(TimeCardEmployeeTypeEnum.DivisionManager))
throw new ArgumentException("Property cannot be changed once the division manager signature has been set.", "ManagerSignature");
if (value != null) {
if (value.Length > 1024)
throw new ArgumentException("Signature cannot be larger than 1KB.", "ManagerSignature");
this.m_TimeEntries.Root.SetAttributeValue("ManagerSignature", Convert.ToBase64String(value));
} else {
var attribute = this.m_TimeEntries.Root.Attribute("ManagerSignature");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("ManagerSignature");
}
}
[IgnoreDataMember]
[DatabaseGenerated(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Computed)]
public Guid? DivisionManagerID {
get {
var attribute = this.m_TimeEntries.Root.Attribute("DivisionManagerID");
if (attribute != null)
return (Guid)attribute;
return null;
}
set {
if (value.HasValue) {
if (value.Value == Guid.Empty)
throw new ArgumentNullException("DivisionManagerID");
this.m_TimeEntries.Root.SetAttributeValue("DivisionManagerID", value);
} else {
var attribute = this.m_TimeEntries.Root.Attribute("DivisionManagerID");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("DivisionManagerID");
}
}
public virtual EmployeeRecord DivisionManager { get; set; }
[NotMapped]
[IgnoreDataMember]
public DateTime? DivisionManagerApprovalDate {
get {
var attribute = this.m_TimeEntries.Root.Attribute("DivisionManagerApprovalDate");
if (attribute != null)
return (DateTime)attribute;
return null;
}
set {
if (value.HasValue)
this.m_TimeEntries.Root.SetAttributeValue("DivisionManagerApprovalDate", value);
else {
var attribute = this.m_TimeEntries.Root.Attribute("DivisionManagerApprovalDate");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("DivisionManagerApprovalDate");
}
}
[NotMapped]
[IgnoreDataMember]
public byte[] DivisionManagerSignature {
get {
var attribute = this.m_TimeEntries.Root.Attribute("DivisionManagerSignature");
if (attribute != null)
return Convert.FromBase64String((string)attribute);
return null;
}
set {
if (value != null) {
if (value.Length > 1024)
throw new ArgumentException("Signature cannot be larger than 1KB.", "DivisionManagerSignature");
this.m_TimeEntries.Root.SetAttributeValue("DivisionManagerSignature", Convert.ToBase64String(value));
} else {
var attribute = this.m_TimeEntries.Root.Attribute("DivisionManagerSignature");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("DivisionManagerSignature");
}
}
#endregion
}
This is the db context declaration
public sealed class DatabaseContext : DbContext {
public DatabaseContext(bool autoDetectChangesEnabled = false, bool lazyLoadingEnabled = false, bool proxyCreationEnabled = false, bool validateOnSaveEnabled = false) {
this.Configuration.AutoDetectChangesEnabled = autoDetectChangesEnabled;
this.Configuration.LazyLoadingEnabled = lazyLoadingEnabled;
this.Configuration.ProxyCreationEnabled = proxyCreationEnabled;
this.Configuration.ValidateOnSaveEnabled = validateOnSaveEnabled;
}
public DbSet<EmployeeRecord> EmployeeRecords { get; set; }
public DbSet<TimeCardEntry> TimeCards { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder) {
modelBuilder.Conventions.Remove<System.Data.Entity.Infrastructure.IncludeMetadataConvention>();
}
}
UPDATE
I have to add another observed behavior of EF. When I add the "NotMappedAttribute" to the EmployeeID column of TimeCardEntry, I get another issue. The EF addes a "Employee_ID" column back to the auto-gen schema. See the TSQL Profile Trace below:
exec sp_executesql N'SELECT
[Limit1].[C1] AS [C1],
[Limit1].[ID] AS [ID],
[Limit1].[TimeEntriesXml] AS [TimeEntriesXml],
[Limit1].[ManagerID] AS [ManagerID],
[Limit1].[DivisionManagerID] AS [DivisionManagerID],
[Limit1].[CreatedBy] AS [CreatedBy],
[Limit1].[Created] AS [Created],
[Limit1].[UpdatedBy] AS [UpdatedBy],
[Limit1].[Updated] AS [Updated],
[Limit1].[Employee_ID] AS [Employee_ID]
FROM ( SELECT TOP (2)
[Extent1].[ID] AS [ID],
[Extent1].[TimeEntriesXml] AS [TimeEntriesXml],
[Extent1].[ManagerID] AS [ManagerID],
[Extent1].[DivisionManagerID] AS [DivisionManagerID],
[Extent1].[CreatedBy] AS [CreatedBy],
[Extent1].[Created] AS [Created],
[Extent1].[UpdatedBy] AS [UpdatedBy],
[Extent1].[Updated] AS [Updated],
[Extent1].[Employee_ID] AS [Employee_ID],
1 AS [C1]
FROM [TimeCard].[TimeCardEntry] AS [Extent1]
WHERE [Extent1].[ID] = #p0
) AS [Limit1]',N'#p0 uniqueidentifier',#p0='10F3E723-4E12-48CD-8750-5922A1E42AA3'
EF is trying to declare Employee_ID in the database because it needs column for foreign key to Employee table. It cannot use your EmployeeID property and its columns as foreign key because it is declared as computed - foreign keys in EF must not be declared as computed or identity (it is not supported).
Solution for your model either requires abandoning navigation properties and work with IDs only (and loading related employees manually) or abandoning those computed columns - I can imagine that both options may be quite annoying.
I wrote a Silverlight MVVM (SimpleMVVM toolkit) Ria Services App with EntityFramework Model generated from exsisting DB.
At first ViewModel of Page which display list parent entities I load parents, after selecting one, I can further go to edition page, where I do menagent of child entities. Before that, I pass parent Entity by pageDataHelper - key value pair Dictionary, which it holds, to ViewModel of Edition Page, and refresh it from database.
Next, I can load by entity primary key, it's childs to ListBox. By this, i can do CRUD's of childs. Anfortunatly, when I want to update one one of them, I got:
The UPDATE statement conflicted with the FOREIGN KEY constraint
"FK_Pozycje_Kosztorysy" The conflict occurred in database
"D:...\APP_DATA\EMS.MDF", table "dbo.Kosztorysy", column 'KosID'.
Aplication makes updates in DB, but entityframework always throws exception, which I handle...
Both tables in db have set On Update/Delete Cascade.
Entities looks:
internal sealed class KosztorysMetadata
{
public int KosID { get; set; }//Primary Key
public EntityCollection<Pozycja> Pozycje { get; set; } //Childs
}
}
internal sealed class PozycjaMetadata
{
public int KosID { get; set; }// Foreign Key
public int PozID { get; set; }//Primary Key
}
}
In App.Web, functins to get entities:
public IQueryable<Kosztorys> GetKosztorysByID(int id)
{
var query = from k in this.ObjectContext.Kosztorysy
where k.KosID==id
select k;
return query;
}
public IQueryable<Pozycja> GetPozycjeGlowne(Int32 id)
{
var query = from k in this.ObjectContext.Pozycje
where k.KosID == id && (k.NadPozID == null || k.TypRMS == 0 || k.TypRMS == TypRMSBVals.Dzial)
select k;
return query;
}
In ViewModel;
class KosztorysViewModel{
public Kosztorys WybranyKosztorys
{
get { return wybranyKosztorys; }
set{ WybranyKosztorys = value;}}
private ObservableCollection<Kosztorys> kosztorysy;
public ObservableCollection<Kosztorys> Kosztorysy{}}
public void OdsiwezKosztorys()//Refresh parent
{ this.serviceAgent.PobKosztorys(WybranyKosztorys.KosID, (encje, ex) => { kosztorysOdswiezony(encje, blad); });
}
void kosztorysOdswiezony(List<Kosztorys> encje, Exception exc) //Refreshed Parent
{ Kosztorysy = new ObservableCollection<Kosztorys>(encje);
WybranyKosztorys = Kosztorysy[0];}
public void PobDzialy()
{
if (WybranyKosztorys != null)
{
this.serviceAgent.PobGlownePozycje(WybranyKosztorys.KosID, (encje, ex) => dzialyPobrane(encje, ex));
}
}
void dzialyPobrane(List<Pozycja> encje, Exception exc) //callback
{
Dzialy.Clear();
Dzialy = new ObservableCollection<Pozycja>(encje);
}}
What's wrong? I use ;EF4.3, Silverlight 5, MS SQL Server 2008R
I'm a newbie with Entity Framework, and I have looked at the questions with the same title, but I haven't found a satisfying answer yet.
Here is my class:
public class MyUser
{
public string FirstName { get; set; }
public virtual ICollection<ProfileSkillEdu> Skills { get; set; }
}
And in the controller I have:
[HttpPost]
public ActionResult EditProfile(MyUser user, string emailAddress)
{
try
{
if (ModelState.IsValid)
{
_unitOfWork.GetMyUserRepository().Update(user);
_unitOfWork.Save();
return View(user);
}
}
catch (DataException)
{
//Log the error
ModelState.AddModelError("", "Unable to save changes. Try again, and if the problem persists see your system administrator.");
}
return View(user);
}
In my user repository:
public virtual void Update(TEntity entityToUpdate)
{
dbSet.Attach(entityToUpdate);
context.Entry(entityToUpdate).State = EntityState.Modified;
}
I keep getting An object with the same key already exists in the ObjectStateManager. The ObjectStateManager cannot track multiple objects with the same key. at dbSet.Attach(entityToUpdate). I watched the variables and I found that if MyUser has only 1 Skill object, it's fine because when it does Attach, the key is unique (value is 0). But if MyUser has 2 skill objects, both primary key have the value of 0 and therefore the error.
Can someone explain why all the Skill object's primary key have the values of 0? Also, is there a simple solution to this problem? I thought it's supposed to be straight forward but I have been struggling with this for hours.
Edit:
I wonder if the problem is because of how I use the context.
In the controller definition I have:
public class MyAccountController : Controller
{
IUnitOfWork _unitOfWork;
public ActionResult EditProfile()
{
if (_user == null)
{
MembershipUser currentUser = Membership.GetUser();
if (currentUser == null)
{
return RedirectToAction("Logon", "Account");
}
Guid currentUserId = (Guid)currentUser.ProviderUserKey;
MyUserService svc = new MyUserService();
MyUser user = svc.GetUserLoaded(currentUserId); //this uses include/eager loading to get the Skills too.
if (user == null)
{
return RedirectToAction("Logon", "Account");
}
else
_user = user;
}
return View(_user);
}
}
In my UnitOfWork I have:
public class UnitOfWork:IUnitOfWork
{
private GlobalContext context = new GlobalContext();
private GenericRepository<MyUser> myUserRepository;
private GenericRepository<Skill> skillRepository;
.. and implementation of Save() and Dispose()
}