This is my class in Entity Framework Code-Firts (I made it smaller in question):
public class dslam
{
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int id { get; set; }
[ForeignKey("center")]
public int centerId { get; set; }
public center center { get; set; }
[MaxLength(50)]
[DisplayName("Title")]
public string title { get; set; }
[MaxLength(20)]
[DisplayName("Type")]
public string type { get; set; }
[MaxLength(5)]
[DisplayName("Port")]
public string port { get; set; }
[MaxLength(20)]
[DisplayName("Host")]
public string host { get; set; }
}
This is client side code:
detailHub.client.setDSLAMInfo = function (liDslams) {
alert('test');
}
If I use dslam class like this, alert('test'); will trigger in my client side:
List<dslam> liDSLAMS = new List<dslam>();
liDSLAMS.Add(new dslam { title = "1", Type= "2", Port= "3" });
var foo = JsonConvert.SerializeObject(liDSLAMS);
Clients.Client(hubConnectionId).setDSLAMInfo(foo);
But I can't use ToList(), it seems ToList() will break something and alert('test'); will not trigger:
List<dslam> liDSLAMS = new List<dslam>();
liDSLAMS = ed.dslams.Where(x => x.centerId == 1).ToList();
//this line will not work properly I guess ToList(); broke something
//var foo = JsonConvert.SerializeObject(liDSLAMS);
Clients.Client(hubConnectionId).setDSLAMInfo(foo);
Edit:
liDSLAMS is not null:
Ok, problem was with Navigation Properties.
It seems objects with navigation property are not able to be sent to client side. Also they are not convertible to JSON. Just select needed properties except navigation properties.
var liDSLAM = ed.dslams.Where(x => x.centerId == 1).Select(x => new { x.id, x.title }).ToList();
Clients.Client(hubConnectionId).setDSLAMInfo(liDSLAM);
Related
I am trying to hide the real Ids of the objects in a database using Automapper's value converters, however they are not called when projecting one to the other.
Nothing special, I would like to use Hashids to convert the int ID to a random string ID (DB->DTO) and vice versa. I want to do this for every object and every ID, but instead of my converter getting called the id's in the database simply get converted strings (so 1 would become "1" instead of for example "sd2+a!F").
My Class:
public class Category
{
public Category(string name)
{
Name = name;
}
public int Id { get; set; }
public string Name { get; set; }
public int? ParentCategoryId { get; set; }
public Category? ParentCategory { get; set; }
public ICollection<Foodstuff> Foodstuffs { get; } = new List<Foodstuff>();
public ICollection<int> FoodstuffIds { get; } = new List<int>();
public byte[] RowVersion { get; set; }
}
My DTO:
public record class Category : IGenerateETag
{
public Category(string name)
{
Name = name;
}
public string Id { get; init; }
[Required(ErrorMessage = "Category name is required.", AllowEmptyStrings = false)]
public string Name { get; init; }
public string? ParentCategoryId { get; init; }
public byte[] RowVersion { get; set; }
}
My converters:
public class HideIdConverter : IValueConverter<int, string>
{
public string Convert(int sourceMember, ResolutionContext context)
{
var hashids = new Hashids();
var shadow = hashids.Encode(sourceMember);
return shadow;
}
}
public class UnhideIdConverter : IValueConverter<string, int>
{
public int Convert(string sourceMember, ResolutionContext context)
{
var hashids = new Hashids();
var plain = hashids.Decode(sourceMember);
return plain[0]; // TODO check this;
}
}
Aaand my Automapper config:
CreateMap<Dal.Entities.Category, Category>()
.ForMember(dest => dest.Id, opt => opt.ConvertUsing(new HideIdConverter(), src => src.Id))
.ReverseMap()
.ForMember(dest => dest.Id, opt => opt.ConvertUsing(new UnhideIdConverter(), src => src.Id));
It turns out that it this is not possible, because I was using LINQ expressions, especially ProjectTo(). It is stated that:
Value converters are only used for in-memory mapping execution. They will not work for ProjectTo.
Source.
I guess I will have to map the objects after I queried them from my database.
I'm trying to map objects with AutoMapper. I've created the HTTP POST controller method, which should create the new Part object to database. It should add data to both entities, Part and PartAvailabilites. Database is already existing and is scaffolded by EF Core. The error I'm receiving is:
AutoMapper created this type map for you, but your types cannot be mapped using the current configuration Part -> PartDto (Destination member list)PartManagement.Entities.Part -> PartManagement.Dto.PartDto (Unmapped properties:Balance)"
Does anyone know what could be the problem with this mapping? I tried to do the mapping in several ways but none of them is working.
Here is my mapping:
CreateMap<PartDto, PartEntity>()
.ForMember(dest => dest.FkPartAvailability,
opts => opts.MapFrom(src => new PartAvailabilities
{
Balance = src.Balance
}));
Example JSON request:
{
"name": "testPart",
"catalogNumber": 12345,
"balance": 10
}
Here are my entity classes:
public class Part
{
public long Id { get; set; }
public int PartNumber { get; set; }
public string Name { get; set; }
public PartAvailabilities FkPartAvailability { get; set; }
}
public class PartAvailabilities
{
public PartAvailabilities()
{
Parts = new HashSet<Part>();
}
public long Id { get; set; }
public decimal Balance { get; set; }
public ICollection<Part> Parts { get; set; }
}
public class PartDto
{
public string Name { get; set; }
public int PartNumber { get; set; }
public decimal Balance { get; set; }
}
This is Create method in the ManagementService class:
public async Task<PartDto> Create(PartDto request)
{
var part = _mapper.Map<PartDto, PartEntity>(request);
var createdPart = partRepository.Add(part);
await partRepository.UnitOfWork.SaveChangesAsync();
return _mapper.Map<PartDto>(createdPart);
}
And here is HttpPost method from controller:
[HttpPost]
public async Task<IActionResult> Part_Create([FromBody] PartDto request)
{
PartDto createdPart;
try
{
if (request != null)
{
createdPart = await _partManagementService.Create(request);
return Ok(request);
}
}
catch(Exception ex)
{
return BadRequest(ex.Message);
}
return Ok(new string[] { "Part created" });
}
The message is trying to tell you that there is no map between Part and PartDto. AM will create a map for you, but that map is not valid, because PartDto.Balance cannot be mapped. So you have to create the map and tell AM how to map Balance. Things might be easier to understand if you set CreateMissingTypeMaps to false.
I get an error when I try to insert a value in my Table.
_dltype is an object of type BRIDownloadType.
using (var db = new BRIDatabase())
{
foreach (var client in db.BRIClients)
{
var todo = new BRIToDo
{
BRIClient = client,
BRIDownloadType = _dltype,
};
db.BRIToDos.Add(todo);
}
db.SaveChanges();
}
Now I get the error:
An Explict Value can't be inserted in the Idendity Column in the BRIDownloadTypes-Table when IDENTITY_INSERT is OFF.
My 2 Tables are
BRIDownloadType
public class BRIDownloadType
{
[Key]
public int DlTypeId { get; set; }
[Required]
[StringLength(15)]
public string DlType { get; set; }
public string Username { get; set; }
public string Password { get; set; }
public virtual ICollection<BRIToDo> BRIToDo { get; set; }
}
BRITodo
public class BRIToDo
{
[Key]
public int ToDoId { get; set; }
[ForeignKey("BRIClient")]
public int ClientId { get; set; }
[ForeignKey("BRITask")]
public int TaskId { get; set; }
public virtual BRIClient BRIClient { get; set; }
public virtual BRITask BRITask { get; set; }
[ForeignKey("BRIDownloadType")]
public int DlTypeId { get; set; }
public virtual BRIDownloadType BRIDownloadType { get; set; }**
}
The interesting thing is, if I do something with my _dltype object, I can use it.
The following code is working and I don't understand why, I'm inserting the exact same object.
using (var db = new BRIDatabase())
{
var dl = db.BRIDownloadTypes.FirstOrDefault(c => c.DlTypeId == _dltype.DlTypeId);
foreach (var client in db.BRIClients)
{
var todo = new BRIToDo
{
BRIClient = client,
BRIDownloadType = _dltype,
};
db.BRIToDos.Add(todo);
}
db.SaveChanges();
}
Can anybody explain to me, why the last approach is working and the first is throwing that error? I just added the line
var dl = db.BRIDownloadTypes.FirstOrDefault(c => c.DlTypeId == _dltype.DlTypeId)
But I'm still inserting the same object. If I insert the Id of the object instead of the object it is also working fine. I have no idea whats going on there.
I want to remove a row in database and insert it again with the same Id, It sounds ridiculous, but here is the scenario:
The domain classes are as follows:
public class SomeClass
{
public int SomeClassId { get; set; }
public string Name { get; set; }
public virtual Behavior Behavior { get; set; }
}
public abstract class Behavior
{
public int BehaviorId { get; set; }
}
public class BehaviorA : Behavior
{
public string BehaviorASpecific { get; set; }
}
public class BehaviorB : Behavior
{
public string BehaviorBSpecific { get; set; }
}
The entity context is
public class TestContext : DbContext
{
public DbSet<SomeClass> SomeClasses { get; set; }
public DbSet<Behavior> Behaviors { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
modelBuilder.Entity<SomeClass>()
.HasOptional(s => s.Behavior)
.WithRequired()
.WillCascadeOnDelete(true);
}
}
Now this code can be executed to demonstrate the point
(described with comments in the code below)
using(TestContext db = new TestContext())
{
var someClass = new SomeClass() { Name = "A" };
someClass.Behavior = new BehaviorA() { BehaviorASpecific = "Behavior A" };
db.SomeClasses.Add(someClass);
// Here I have two classes with the state of added which make sense
var modifiedEntities = db.ChangeTracker.Entries()
.Where(entity => entity.State != System.Data.Entity.EntityState.Unchanged).ToList();
// They save with no problem
db.SaveChanges();
// Now I want to change the behavior and it causes entity to try to remove the behavior and add it again
someClass.Behavior = new BehaviorB() { BehaviorBSpecific = "Behavior B" };
// Here it can be seen that we have a behavior A with the state of deleted and
// behavior B with the state of added
modifiedEntities = db.ChangeTracker.Entries()
.Where(entity => entity.State != System.Data.Entity.EntityState.Unchanged).ToList();
// But in reality when entity sends the query to the database it replaces the
// remove and insert with an update query (this can be seen in the SQL Profiler)
// which causes the discrimenator to remain the same where it should change.
db.SaveChanges();
}
How to change this entity behavior so that delete and insert happens instead of the update?
A possible solution is to make the changes in 2 different steps: before someClass.Behavior = new BehaviorB() { BehaviorBSpecific = "Behavior B" }; insert
someClass.Behaviour = null;
db.SaveChanges();
The behaviour is related to the database model. BehaviourA and B in EF are related to the same EntityRecordInfo and has the same EntitySet (Behaviors).
You have the same behaviour also if you create 2 different DbSets on the context because the DB model remains the same.
EDIT
Another way to achieve a similar result of 1-1 relationship is using ComplexType. They works also with inheritance.
Here an example
public class TestContext : DbContext
{
public TestContext(DbConnection connection) : base(connection, true) { }
public DbSet<Friend> Friends { get; set; }
public DbSet<LessThanFriend> LessThanFriends { get; set; }
}
public class Friend
{
public Friend()
{Address = new FullAddress();}
public int Id { get; set; }
public string Name { get; set; }
public FullAddress Address { get; set; }
}
public class LessThanFriend
{
public LessThanFriend()
{Address = new CityAddress();}
public int Id { get; set; }
public string Name { get; set; }
public CityAddress Address { get; set; }
}
[ComplexType]
public class CityAddress
{
public string Cap { get; set; }
public string City { get; set; }
}
[ComplexType]
public class FullAddress : CityAddress
{
public string Street { get; set; }
}
Stuck on a strange issue, that works using my get method but fails when returning iqueryable. Some limitation when using projection or iqueryable?
My code looks like below, simplified:
public class SimpleEntity
{
public long Id { get; set; }
public string Name { get; set; }
public virtual SimpleEntity Parent { get; set; }
public virtual ICollection<SimpleEntity> Children { get; set; }
public SimpleEntity()
{
Children = new List<SimpleEntity>();
}
}
public class SimpleEntityResponseDTO
{
public long Id { get; set; }
public string Name { get; set; }
public NameValueItem ParentReferral { get; set; }
public IEnumerable<NameValueItem> ChildReferrals { get; set; }
public NavigationFolderResponseDTO()
{
ChildReferrals = new List<NameValueItem>();
}
}
public class NameValueItem
{
public long Value { get; set; }
public string Name { get; set; }
}
The web api actions:
[HttpGet, Queryable]
public IQueryable<SimpleEntityResponseDTO> List()
{
//Generic crudservice returning an iqueryable based on Set<SimpleEntity>
return _crudService.QueryableList().Project().To<SimpleEntityResponseDTO>();
}
[HttpGet]
public HttpResponseMessage Get(long id)
{
SimpleEntity result = _crudSrv.Get(id);
if (result != null)
return Request.CreateResponse<SimpleEntityResponseDTO>(HttpStatusCode.OK, Mapper.Map<SimpleEntity , SimpleEntityResponseDTO>(result));
else
return Request.CreateResponse(HttpStatusCode.NotFound);
}
And now the mapping:
Mapper.CreateMap<SimpleEntity, SimpleEntityResponseDTO>()
.ForMember(to => to.ParentReferral, opt => opt.MapFrom(from => new NameValueItem { Name = from.Parent.Name, Value = from.Parent.Id }))
.ForMember(to => to.ChildReferrals, opt => opt.MapFrom(from => from.Children.Select(o => new NameValueItem {Name = o.Name, Value = o.Id}).ToList() ));
The parent mapping works no matter what. But the Children mapping is causing below issue.
When retrieving an object through the get method everything works, no matter wich entity i retrieve. When using List i get "Object reference not set to an instance of an object", "d__b.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n". Tried for example adding $filter=Id eq 5 (or whatever id) but results in same issue. Perhaps someone can hint me to what goes wrong here?