using .net 4.5.2, MVC5, Entity framework 6 and visual studio 2015.
I have a repository pattern set up with Ninject as my DI here is the common file.
private static void RegisterServices(IKernel kernel)
{
kernel.Bind<ApplicationDbContext>().ToSelf().InRequestScope();
kernel.Bind<IUserBlueRayLists>().To<UserBlueRayListRepository>().InRequestScope();
kernel.Bind<IBlueRays>().To<BlueRaysRepository>().InRequestScope();
}
my Context
public ApplicationDbContext()
: base("DefaultConnection", throwIfV1Schema: false)
{
}
public static ApplicationDbContext Create()
{
return new ApplicationDbContext();
}
public IDbSet<UserBlueRayList> UserBlueRayLists { get; set; }
public IDbSet<BlueRays> BlueRays { get; set; }
public new void SaveChanges()
{
base.SaveChanges();
}
}
public interface IDevTestContext
{
IDbSet<UserBlueRayList> UserBlueRayLists { get; set; }
IDbSet<BlueRays> BlueRays { get; set; }
void SaveChanges();
}
Then my Repository update method.
public bool Update(UserBlueRayList item)
{
var userBRList = _db.UserBlueRayLists.FirstOrDefault(x => x.Id == item.Id);
if(userBRList != null)
{
userBRList = item;
//_db.Entry(userBRList).State = EntityState.Modified;
_db.SaveChanges();
return true;
}
return false;
}
Now when i save via my controller and call the repository update method, nothing is updated.
So i use
_db.Entry(userBRList).State = EntityState.Modified;
But i get an error,
Additional information: Attaching an entity of type 'myapp.Models.UserBlueRayList' failed because another entity of the same type already has the same primary key value. This can happen when using the 'Attach' method or setting the state of an entity to 'Unchanged' or 'Modified' if any entities in the graph have conflicting key values... etc
Many to many models, userlist model.
public class UserBlueRayList
{
public UserBlueRayList()
{
this.BlueRays = new HashSet<BlueRays>();
}
[Key]
public int Id { get; set; }
[Required]
public string Name { get; set; }
[Required]
public string Description { get; set; }
[Required]
public string UserId { get; set; }
public virtual ICollection<BlueRays> BlueRays { get; set; }
}
And the
public class BlueRays
{
public BlueRays()
{
this.UserBlueRayList = new HashSet<UserBlueRayList>();
}
[Key]
public int Id { get; set; }
[Required]
public string Name { get; set; }
[Required]
public string Description { get; set; }
public virtual ICollection<UserBlueRayList> UserBlueRayList { get; set; }
}
Question is why this wont update, and why it errors if i try to set state to modified.
Since you are using EF6, you may try to use auto property mapping built into EF6
public bool Update(UserBlueRayList item)
{
var userBRList = _db.UserBlueRayLists.FirstOrDefault(x => x.Id == item.Id);
if(userBRList != null)
{
_dbContext.Entry(userBRList).CurrentValues.SetValues(item);
return return _dbContext.SaveChanges() > 0;
}
return false;
}
Cheers
First Solution you have to update like that
public bool Update(UserBlueRayList item)
{
var userBRList = _db.UserBlueRayLists.FirstOrDefault(x => x.Id == item.Id);
if(userBRList != null)
{
userBRList.Name = item.Name;
//value assign to other entity
_db.Entry(userBRList).State = EntityState.Modified;
_db.SaveChanges();
return true;
}
return false;
}
if this will not solve your problem you Find method instead of FirstorDefault()
public bool Update(UserBlueRayList item)
{
var userBRList = _db.UserBlueRayLists.Find(x => x.Id == item.Id);
if(userBRList != null)
{
userBRList.Name = item.Name;
//value assign to other entity
_db.Entry(userBRList).State = EntityState.Modified;
_db.SaveChanges();
return true;
}
return false;
}
Related
I'm trying to create a update for EF Core 6 many-to-many on SQL Server but I am really confused. I have stock.cs class and location.cs class
public class Stock : BaseModel
{
public Stock()
{
this.Locations = new List<Location>();
}
[Key]
public int Id { get; set; }
public string Name { get; set; } = string.Empty;
public string Guid { get; set; } = string.Empty;
public string RackBarNumber { get; set; } = string.Empty;
public string ShelveNumber { get; set; } = string.Empty;
public string ShelveName { get; set; } = string.Empty;
public virtual List<Location>? Locations { get; set; }
}
public class Location : BaseModel
{
public Location()
{
this.Stocks = new List<Stock>();
}
[Key]
public int Id { get; set; }
public string Name { get; set; } = string.Empty;
public string? Description { get; set; }
public virtual List<Stock>? Stocks { get; set; }
}
I use this as my DTO for getting all my current locations
public class StockLocations
{
public Stock Stock { get; set; }
public virtual ICollection<Location> currentLocations { get; set; }
}
Now the StockController is the piece of code which updates the fields, I am able to create and delete in the StockLocation table that EF Core creates. But when I try many updates at once it just goes haywire.
This is my last attempt:
[HttpPut("{id}")]
public async Task<IActionResult> PutStock(int id, StockLocations stockLocation)
{
await _userService.ConfirmUser(User);
stockLocation.Stock.UpdatedAt = DateTime.Now;
List<Location> removedLocations = new List<Location>();
if (id != stockLocation.Stock.Id)
{
return BadRequest();
}
_context.Entry(stockLocation.Stock).State = EntityState.Modified;
try
{
await _context.SaveChangesAsync();
// Add new items to the database
foreach (var item in stockLocation.Stock.Locations)
{
if (!stockLocation.currentLocations.Any(x => x.Id == item.Id))
{
_context.Entry(item).State = EntityState.Modified;
await _context.SaveChangesAsync();
}
}
// Create a list of removed locations to be removed from the database
foreach (Location location in stockLocation.currentLocations)
{
if (!stockLocation.Stock.Locations.Any(x => x.Id == location.Id))
{
removedLocations.Add(location);
}
}
foreach (var item in removedLocations)
{
/*
Stock stock = _context.Stocks.Include(x => x.Locations).Single(x => x.Id == id);
Location locationToDelete = stock.Locations.Find(x => x.Id == item.Id);
stock.Locations.Remove(locationToDelete);
await _context.SaveChangesAsync();
*/
}
}
catch (DbUpdateConcurrencyException)
{
return NoContent();
}
return NoContent();
}
Anyone who is willing to tell me how I can approach this properly?
Since you need to update StockLocations I will recommend that tyou just pull the record from the database such as:
var record = await _context.StockLocations
.Include(a=>a.Location).Include(a=>a.Stock)
.FirstOrDefaultAsync(a=>a.id == id);
if(record == null) {
thrown new NotFoundException();
}
stockLocation.Stock.UpdatedAt = DateTime.Now;
await _context.SaveChangesAsync();
// other code
// add new location to the db if they don't exist
var locations = stockLocation.Location;
foreach(var loc in locations) {
var findLocation =
_context.Locations.FirstOrDefault(a=>a.Name.ToLower() ==
loc.Name.ToLower()) ;
if(findLocation == null){
// does not exist and can be added
}
}
I have the following models in my API:
namespace API.Models
{
public class StudentDetailsViewModel
{
[Key]
public int StudentId { get; set; }
public AddressViewModel Address { get; set; }
public List<CoursesViewModel> Courses { get; set; }
}
public class AddressViewModel
{
public int AddressId { get; set; }
public int StudentId { get; set; }
public string Address { set; set; }
}
public CoursesViewModel
{
public int CourseId { get; set; }
public int StudentId { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public string Grade { get; set; }
}
}
I am writing a PUT method for StudentDetailsViewModel. The list in this model could have a number of records removed or added or a number of fields in one of the records updated. For example, grade for one of the courses updated or a course added or dropped.
What is the best approach in updating a model containing an object list like the above? Is it best to delete the entire list and re-add them?
I have the following thus far:
[ResponseType(typeof(void))]
public async Task<IHttpActionResult> PutStudenDetailsViewModel(StudentDetailsViewModel studentDetailsViewModel)
{
if(!ModelState.IsValid)
return BadRequest(ModelState);
var address = new DataAccess.Address
{
AddressID = studentDetailsViewModel.Address.AddessId,
StudentID = studentDetailsViewModel.Address.StudentId,
Address = studentDetailsViewModel.Address.Address
};
_context.Entry(address).State = EntityState.Modified;
// TODO: This is where the list Course entity needs to be updated
try
{
await _context.SaveChangesAsync();
}
catch(DbUpdateConcurrencyException)
{
if(!AddressViewModelExists(address.AddressID))
return NotFound();
throw;
}
return StatusCode(HttpStatusCode.NoContent);
}
Just an example from MS documentation for EF Core
public static void InsertOrUpdateGraph(BloggingContext context, Blog blog)
{
var existingBlog = context.Blogs
.Include(b => b.Posts)
.FirstOrDefault(b => b.BlogId == blog.BlogId);
if (existingBlog == null)
{
context.Add(blog); //or 404 response, or custom exception, etc...
}
else
{
context.Entry(existingBlog).CurrentValues.SetValues(blog);
foreach (var post in blog.Posts)
{
var existingPost = existingBlog.Posts
.FirstOrDefault(p => p.PostId == post.PostId);
if (existingPost == null)
{
existingBlog.Posts.Add(post);
}
else
{
context.Entry(existingPost).CurrentValues.SetValues(post);
}
}
}
context.SaveChanges();
}
after i set the AuditReport on my Audit and save it, (in Debugger it is filled with a Proxy) there is still no Entry in the Database and I have no Idea why. Here are the relevant classes:
public class AuditReport
{
[Key]
[ForeignKey("Audit")]
[Column("AuditReport_ID")]
public int ID { get; set; }
[Required]
public virtual Audit Audit { get; set; }
}
public class Audit
{
[Key]
public int GeneratedID { get; set; }
[Index("Audit_ID", IsUnique = true)]
public int Audit_ID { get; set; }
public virtual AuditReport AuditReport { get; set; }
}
And the method in that the new AuditReport is Created
public async override Task SaveChangesAsync()
{
using (var dbAccess = new DatabaseAccess())
{
var foundAudit = dbAccess.Audits.Include("AuditReport").Include("AuditReport.Stellungnahmen").SingleOrDefault(_ => _.Audit_ID == Audit.Audit_ID);
if (foundAudit != null)
{
if (foundAudit.AuditReport == null)
{
foundAudit.AuditReport = dbAccess.AuditReports.Create();
foundAudit.AuditReport.Audit = foundAudit;
}
else
foundAudit.AuditReport.Stellungnahmen.ToList().ForEach(_ => dbAccess.Entry(_).State = EntityState.Deleted);
foreach (var item in Stellungnahmen.Where(_ => _.IsChecked == true))
foundAudit.AuditReport.Stellungnahmen.Add(dbAccess.Stellungnahmen.SingleOrDefault(_ => _.KeyWord == item.KeyWord));
}
await dbAccess.SaveChangesAsync();
}
}
As i already said, I've already debugged it and everything looks fine.
Try to remove [Key] on ID since you already have [ForeignKey] atrribute.
I'm using EF code first with the following model:
public class Root
{
public ChildA A { get; set; }
public ChildB B { get; set; }
public ChildC C { get; set; }
}
Suppose you have a controller
public class RecordController
{
...
public void Save(Root root)
{
...
}
...
}
and your Root controller has received a model from client that contains the following changes: property A is totally new it has not yet been added to database and needs to be created, property B already exists in database and needs to be updated, property C not changed.
Action Save is not aware of what the property changes are, it just needs to update the Record properly and create missing or update existing sub models, it is also possible that some Child classes may also have their own nested changes, so I need a method that will somehow recurse through the model compare new model to existing one and will apply appropriate changes. So how do I do that?
I've ended up with concatenating each of my model and ViewModel classes with EntityState property, so now when I change some property I set the EntityState to changed state, when I create one I set the property to state Added, initially models are initialised with Unchanged state, basically it looks something like the following:
[Table("City")]
[KnownType(typeof(Country))]
public class City
{
public City()
{
Airports = new List<Airport>();
LastUpdate = DateTime.Now;
}
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public Int32 Id { get; set; }
public Int32? CountryId { get; set; }
[StringLength(50)]
public String Name { get; set; }
[Range(-12, 13)]
public Int32? TimeZone { get; set; }
public Boolean? SummerTime { get; set; }
public DateTime? LastUpdate { get; set; }
[ForeignKey("CountryId")]
public virtual Country Country { get; set; }
[NotMapped]
public EntityState? EntityState { get; set; } // <----------- Here it is
}
Then on server I do the following
[HttpPost, HttpGet]
public HttpResponseMessage SaveRecord(RecordViewModel record)
{
var model = Mapper.Map<Record>(record);
if (!ModelState.IsValid)
{
return Request.CreateErrorResponse(HttpStatusCode.BadRequest, ModelState);
}
db.Attach(model);
try
{
db.SaveChanges();
}
catch (DbUpdateConcurrencyException ex)
{
return Request.CreateErrorResponse(HttpStatusCode.NotFound, ex);
}
return Request.CreateResponse(HttpStatusCode.OK);
}
Here is implementation for Attach method:
public void Attach(City entity)
{
if (entity != null)
{
Attach(entity.Country);
AttachAndMarkAs(entity, entity.EntityState ?? EntityState.Added, instance => instance.Id);
}
}
public void Attach(Country entity)
{
if (entity != null)
{
AttachAndMarkAs(entity, entity.EntityState ?? EntityState.Added, instance => instance.Id);
}
}
AttachAndMarkAs has the following implementation:
public void AttachAndMarkAs<T>(T entity, EntityState state, Func<T, object> id) where T : class
{
var entry = Entry(entity);
if (entry.State == EntityState.Detached)
{
var set = Set<T>();
T attachedEntity = set.Find(id(entity));
if (attachedEntity != null)
{
var attachedEntry = Entry(attachedEntity);
attachedEntry.CurrentValues.SetValues(entity);
}
else
{
entry.State = state;
}
}
}
I need to delete a record of an entity but keep all the records of another entity that is related with it:
Entity record to remove is:
public class Ask
{
// Primary properties
public int Id { get; set; }
public string Title { get; set; }
public string Message { get; set; }
public DateTime DateCreated { get; set; }
}
The related records that I want to keep after deleting an Ask record is of type MessageAsk :
public class Message
{
// Primary properties
public int Id { get; set; }
public string NameFrom { get; set; }
public string EmailFrom { get; set; }
public string TelephoneFrom { get; set; }
public string Title { get; set; }
public string MessageText { get; set; }
public bool? Approved { get; set; }
public DateTime? DateCreated { get; set; }
public DateTime? DateRead { get; set; }
// Navigation properties
public Member MemberFrom { get; set; }
public Member MemberTo { get; set; }
public MessageType MessageType { get; set; }
public Message MessageParent { get; set; }
}
public class MessageAsk : Message
{
public Ask Ask { get; set; }
}
Resuming, I want to delete an Ask and keep all related MessageAsk's.
EDIT:
I use the service Delete:
private readonly IRepository<Ask> _askRepository;
private readonly IRepository<MessageAsk> _messageAskRepository;
public bool Delete(int askId)
{
try
{
Ask askToDelete = _askRepository.GetById(askId);
IList<MessageAsk> relatedMessageAsks = _messageAskRepository.Query.Where(m => m.Ask.Id == askId).ToList();
_askRepository.Delete(askToDelete);
_askRepository.Save();
}
catch
{
return false;
}
return true;
}
And I use a repository to Delete the Entity:
public class Repository<T> : IRepository<T> where T : class
{
protected DbContext _dataContext;
protected DbSet<T> _dbSet;
public Repository(DbContext context)
{
_dataContext = context;
_dbSet = _dataContext.Set<T>();
}
public T NewEntityInstance()
{
return _dbSet.Create();
}
public void Delete(T entity)
{
if (_dataContext.Entry(entity).State == EntityState.Detached)
{
_dbSet.Attach(entity);
}
_dbSet.Remove(entity);
}
public virtual void Delete(object id)
{
T entity = _dbSet.Find(id);
Delete(entity);
}
public T GetById(int id)
{
return _dbSet.Find(id);
}
public virtual IQueryable<T> Query
{
get
{
return _dbSet.AsNoTracking(); <------ SOURCE OF THE PROBLEM - I HAD TO REMOVE THE ASNOTRACKING OPTION TO SOLVE THE PROBLEM
}
}
}
Error I get now:
"The DELETE statement conflicted with the REFERENCE constraint "FK_Messages_Asks". The conflict occurred in database "Heelp", table "dbo.Messages", column 'Ask_Id'.
Thanks
If your relationship is optional (that is, the foreign key from MessageAsk table to Ask table allows NULL values), you can do it this way:
using (var context = new MyContext())
{
var askToDelete = context.Asks.Single(a => a.Id == askToDeleteId);
var relatedMessageAsks = context.MessageAsks
.Where(m => m.Ask.Id == askToDeleteId)
.ToList();
// or just: context.MessageAsks.Where(m => m.Ask.Id == askToDeleteId).Load();
context.Asks.Remove(askToDelete);
// or DeleteObject if you use ObjectContext
context.SaveChanges();
}
(or context.Messages.OfType<MessageAsk>()... instead of context.MessageAsks... if you don't have a set for the derived type in your context)
You don't need to set the MessageAsk.Ask property to null explicitly here. EF will do that automatically when the askToDelete is removed and update the MessageAsk with FK = NULL in the database.
It does not work if the relationship is required (no NULLs for the FK are allowed) as you would violate a referential foreign key constraint in the database when the principal (askToDelete) would be deleted. In that case you need to assign the relatedMessageAsks to another Ask before you delete the askToDelete.