I'm kinda new to MVC entity framework core and I've been struggeling with this exception and I don't know what's causing it.
I always get the same error: System.InvalidOperationException: 'No suitable constructor found for entity type 'Rating'. The following parameters could not be bound to properties of the entity: 'date', 'message', 'suggestion'.'
The error is thrown in the GetAll() method:
public class RatingRepository : IRatingRepository {
private readonly ApplicationDbContext _context;
public RatingRepository(ApplicationDbContext context) {
_context = context;
}
public void Add(Rating rating) {
var any = _context.Ratings.Any(r => r.RatingId == rating.RatingId);
if (!any) {
_context.Add(rating);
}
}
public IEnumerable<Rating> GetAll() {
return _context.Ratings.ToList();
}
public IEnumerable<Rating> GetFirst(int amount) {
return GetAll().Take(amount).ToList();
}
public void Remove(Rating rating) {
var any = _context.Ratings.Any(r => r.RatingId == rating.RatingId);
if (any) {
_context.Remove(rating);
}
}
public void SaveChanges() {
_context.SaveChanges();
}
}
This is the interface the repository implements:
public interface ICodeRepository {
IEnumerable<string> GetAll();
void Remove(string code);
void SaveChanges();
}
This is my Rating class:
public class Rating {
#region Fields
private double _foodRating;
private double _atmosphereRating;
#endregion
#region Properties
public int RatingId { get; set; }
public double FoodRating {
get {
return _foodRating;
}
private set {
if (value < 0.0 || value > 5.0) {
throw new ArgumentException("Give a score between 0 and 5 please.");
}
_foodRating = value;
}
}
public double AtmosphereRating {
get {
return _atmosphereRating;
}
private set {
if (value < 0.0 || value > 5.0) {
throw new ArgumentException("Give a score between 0 and 5 please.");
}
_atmosphereRating = value;
}
}
public string PersonalMessage { get; set; } //not mandatory
public string Suggestions { get; set; } //not mandatory
#endregion
#region Constructors
public Rating(double foodRating, double atmosphereRating, DateTime date, string message = null, string suggestion = null) {
FoodRating = foodRating;
AtmosphereRating = atmosphereRating;
PersonalMessage = message;
Suggestions = suggestion;
}
#endregion
}
This is how I mapped it to the database:
public class RatingConfiguration : IEntityTypeConfiguration<Rating> {
public void Configure(EntityTypeBuilder<Rating> builder) {
builder.ToTable("Rating");
builder.HasKey(r => r.RatingId);
builder.Property(r => r.PersonalMessage)
.HasMaxLength(250)
.IsRequired(false);
builder.Property(r => r.Suggestions)
.HasMaxLength(250)
.IsRequired(false);
}
}
In my ApplicationDb have I forseen a DbSet and in the OnModelCreating have I given the RatingConfiguration with.
I need to bind this to a form result so here is my RatingViewModel:
public class RatingViewModel {
#region Properties
[Required]
[DataType(DataType.Text)]
[Display(Name = "How would you rate the food?")]
public double FoodRating { get; set; }
[Required]
[DataType(DataType.Text)]
[Display(Name = "How would you rate the atmosphere?")]
public double AtmosphereRating { get; set; }
[Display(Name = "Personal message")]
[DataType(DataType.Text)]
[StringLength(250, ErrorMessage = "Suggestion is needs to be between 250 and 0 characters")]
public string PersonalMessage { get; set; }
[Display(Name = "Any suggestions for next time?")]
[DataType(DataType.Text)]
[StringLength(250,ErrorMessage = "Suggestion is needs to be between 250 and 0 characters")]
public string Suggestions { get; set; }
#endregion
#region Constructor
public RatingViewModel() {
}
public RatingViewModel(Rating rating) : this() {
FoodRating = rating.FoodRating;
AtmosphereRating = rating.AtmosphereRating;
PersonalMessage = rating.PersonalMessage;
Suggestions = rating.Suggestions;
}
#endregion
}
Now if any of you can find why this exception is thrown please let me know. If you need anything else from my code, also let me know!
Entity framework will load data and tries to create the mapped objects. However if you specify a constructor, EF will try to use it, but it does not know how to handle your parameters. To fix this, simply add an empty constructor.
Related
I have these two classes:
public class LeadPerformanceItem
{
public string name { get; set; }
public int visitors { get; set; }
public decimal visitorspercentoftotal
{
get
{
// ?
}
}
}
public class LeadPerformanceItemCollection
{
public List<LeadPerformanceItem> items {get;set;}
public int totalvisitors
{
get
{
return items.Sum(x => x.visitors);
}
}
}
Is there anyway my visitorspercentoftotal property could be automatically calculated as items are added and removed from the collection?
public class LeadPerformanceItem
{
public string name { get; set; }
public int Visitors { get; set; }
private int _totalVisitors = 0;
public void UpdateTotalVisitors(int total)
{
this._totalVisitors = total;
}
public decimal Visitorspercentoftotal => _totalVisitors != 0
? Convert.ToDecimal(Math.Round(((double) (Visitors * 100)) / _totalVisitors))
: 0;
}
public class LeadPerformanceItemCollection
{
public List<LeadPerformanceItem> Items { get; set; }
public void AddToItems(LeadPerformanceItem item)
{
Items.Add(item);
var total = Items.Sum(x => x.Visitors);
Items.AsParallel().ForAll(i => i.UpdateTotalVisitors(total));
}
public int totalvisitors
{
get { return Items.Sum(x => x.Visitors); }
}
}
[TestFixture]
public class Class1
{
[Test]
public void Test()
{
var leadPerformanceItemCollection = new LeadPerformanceItemCollection();
leadPerformanceItemCollection.Items=new List<LeadPerformanceItem>();
leadPerformanceItemCollection.AddToItems(new LeadPerformanceItem()
{
name = "test",
Visitors = 10
});
leadPerformanceItemCollection.AddToItems(new LeadPerformanceItem()
{
name = "test2",
Visitors = 25
});
Console.WriteLine(leadPerformanceItemCollection.Items[0].Visitorspercentoftotal);
Console.WriteLine(leadPerformanceItemCollection.Items[1].Visitorspercentoftotal);
}
}
result:
29%
71%
One way would be to inherit from List and hide the Add method and create your own and do the calculation there.
public class LeadPerformanceItemCollection : List<LeadPerformanceItem>
{
public new void Add(LeadPerformanceItem item)
{
//calculate percent of total here
base.Add(item);
}
}
I use AutoMapper 8.1.0 in a asp.net core project. I have an Automapper mapping that doesn't work as I expected. I reproduced the configuration so you can test it by yourself. So I have an ExpenseReport with a collection of ExpenseReportItem and this one with another collection. I have to keep the data of eTaxCollection after the mapping, but they are lost in the process.
So the question is why values of eTaxCollections are lost after calling _mapper.Map(vmodel, model) and how can I keep them?
The ignore attribute don't work. I also tried UseDestinationValue(). I lost 2 days trying to figure it out and I'm exhausted.
public void WeatherForecasts()
{
int[] excludeTaxes = new int[] { 2 };
var vmodel = new ExpenseReportCreateEditModel();
vmodel.Expenses.Add(new ExpenseReportItemModel()
{
ExcludeTaxIds = excludeTaxes,
Total = 12,
Id = 1
});
// fetch from bd
var model = new ExpenseReport();
// values will be lost after _mapper.Map...
var eTaxCollections = new HashSet<ExcludeExpenseReportItemTax>();
eTaxCollections.Add(new ExcludeExpenseReportItemTax()
{
TaxId = 1,
ExpenseReportItemId = 1
});
model.Items.Add(new ExpenseReportItem()
{
ExcludeTaxes = eTaxCollections,
ExpenseReportId = 1,
Id = 9
});
_mapper.Map(vmodel, model);
}
public class ExpenseReportCreateEditModelProfile : Profile
{
public ExpenseReportCreateEditModelProfile()
{
CreateMap<ExpenseReportCreateEditModel, ExpenseReport>()
.ForMember(d => d.Items, s => s.MapFrom(m => m.Expenses));
}
}
public class ExpenseReportItemModelProfile : Profile
{
public ExpenseReportItemModelProfile()
{
CreateMap<ExpenseReportItemModel, ExpenseReportItem>()
.ForMember(d => d.ExcludeTaxes, s => s.Ignore()); // <<<==== data are lost
}
}
public class ExpenseReportCreateEditModel
{
public int Id { get; set; }
public ICollection<ExpenseReportItemModel> Expenses { get; set; }
public ExpenseReportCreateEditModel()
{
Expenses = new HashSet<ExpenseReportItemModel>();
}
}
public class ExpenseReportItemModel
{
public int Id { get; set; }
public ICollection<int> ExcludeTaxIds { get; set; }
public decimal Total { get; set; }
public ExpenseReportItemModel()
{
ExcludeTaxIds = new HashSet<int>();
}
}
public class ExpenseReport
{
public int Id { get; set; }
public virtual ICollection<ExpenseReportItem> Items { get; set; }
public ExpenseReport()
{
Items = new HashSet<ExpenseReportItem>();
}
}
public class ExpenseReportItem
{
public int Id { get; set; }
public int ExpenseReportId { get; set; }
public virtual ICollection<ExcludeExpenseReportItemTax> ExcludeTaxes { get; set; }
public ExpenseReportItem()
{
ExcludeTaxes = new HashSet<ExcludeExpenseReportItemTax>();
}
}
public class ExcludeExpenseReportItemTax
{
public int ExpenseReportItemId { get; set; }
public virtual ExpenseReportItem ExpenseReportItem { get; set; }
public int TaxId { get; set; }
}
Thank you for any help
Edit
I execute the execution plan and perhaps this is the problem:
$typeMapDestination = ($dest ?? .New WebApplication1.Controllers.SampleDataController+ExpenseReportItem());
This is only way I can lost the values.
I have to find a solution now
Here the complete execution plan :
.If ($src == null) {
.Default(WebApplication1.Controllers.SampleDataController+ExpenseReportItem)
} .Else {
.Block() {
$typeMapDestination = ($dest ?? .New WebApplication1.Controllers.SampleDataController+ExpenseReportItem());
.Try {
.Block(System.Int32 $resolvedValue) {
.Block() {
$resolvedValue = .If (
$src == null || False
) {
.Default(System.Int32)
} .Else {
$src.Id
};
$typeMapDestination.Id = $resolvedValue
}
}
} .Catch (System.Exception $ex) {
.Block() {
.Throw .New AutoMapper.AutoMapperMappingException(
"Error mapping types.",
$ex,
.Constant<AutoMapper.TypePair>(AutoMapper.TypePair),
.Constant<AutoMapper.TypeMap>(AutoMapper.TypeMap),
.Constant<AutoMapper.PropertyMap>(AutoMapper.PropertyMap));
.Default(System.Int32)
}
};
$typeMapDestination
}
}
Entity and Component has one-to-many relationship. Entity stored in db correctly, with all components. But when I trying load it back this Entity in Child method Components not loads. If i try use lazy loading, code failing on entity.GetComponent because of Entity.Components isn't initialized. After exception Components are initialized and has zero elements. If I disable lazy loading, Components are initialized and has zero elements. I wrote example for building one-to-many relationship and using lazy initialization, and it works fine.
public static void Main(string[] args)
{
Parent();
Child();
}
private static void Child()
{
using (var db = new EntitiesContext())
{
var entities = from entity in db.Entities
select entity;
foreach (Entity entity in entities)
{
Position pos = entity.GetComponent<Position>();
Core core = entity.GetComponent<Core>();
}
}
}
private static void Parent()
{
Entity entity = new Entity();
entity.AddComponent(new Position(10, 10));
entity.AddComponent(new ObjectName("Entity" + 1));
entity.AddComponent(new Core(100));
using (var db = new EntitiesContext())
{
db.Entities.Add(entity);
db.SaveChanges();
}
}
public class EntitiesContext : DbContext
{
public DbSet<TypeMaskPair> MappedTypes { get; set; }
public DbSet<Entity> Entities { get; set; }
public EntitiesContext()
: base("EntitiesDb")
{
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Entity>()
.HasMany(entity => entity.Components)
.WithRequired(component => component.EntityObj)
.HasForeignKey(component => component.EntityId)
.WillCascadeOnDelete();
//this.Configuration.LazyLoadingEnabled = false;
}
}
public abstract class Component
{
[Key]
public int Id { get; set; }
[Required]
public int EntityId { get; set; }
[Required]
public virtual Entity EntityObj { get; set; }
private static DbMasksMapper componentsMap;
static Component()
{
componentsMap = new DbMasksMapper(typeof(Component));
}
public TypeMask GetMask()
{
return componentsMap.GetMask(this.GetType());
}
public static TypeMask GetMask<T>() where T : Component
{
return componentsMap.GetMask(typeof(T));
}
}
public class Entity
{
[Key]
public int Id { get; set; }
public virtual List<Component> Components { get; set; }
[NotMapped]
public TypeMask Mask { get; private set; }
public string TypeMaskString
{
get{ return Mask.ToString(); }
set{ Mask = new TypeMask(value); }
}
public Entity()
{
Components = new List<Component>();
Mask = new TypeMask();
}
public void AddComponent(Component component)
{
Components.Add(component);
component.EntityObj = this;
Mask |= component.GetMask();
}
public void DeleteComponent(TypeMask componentMask)
{
if (ContainsComponent(componentMask))
{
int removeIndex = Components.FindIndex(c => c.GetMask() == componentMask);
Components.RemoveAt(removeIndex);
Mask &= ~componentMask;
}
}
public Component GetComponent(TypeMask componentMask)
{
return Components.Find(c => c.GetMask() == componentMask);
}
public T GetComponent<T>() where T : Component
{
return (T) GetComponent(Component.GetMask<T>());
}
public bool ContainsComponent<T>() where T : Component
{
return ContainsComponent(Component.GetMask<T>());
}
public bool ContainsComponent(TypeMask componentMask)
{
return (Mask & componentMask) == componentMask;
}
}
class Position : Component
{
public Position(int x = 0, int y = 0)
{
X = x;
Y = y;
}
public int X { get; set; }
public int Y { get; set; }
}
class Cargo : Component
{
public Cargo(int capacity = 0)
{
Capacity = capacity;
}
public int Capacity { get; set; }
}
class Core : Component
{
public Core(int power = 0)
{
Power = power;
}
public int Power { get; set; }
}
class ObjectName : Component
{
public ObjectName(string name = "")
{
Name = name;
}
public string Name { get; set; }
}
I saw similar questions, but didn't found any answer.
Where is a mistake?
Solution
All works after I wrote default constructor for inherited components. But, I don't understand why constructor with default arguments doesn't suitable. Without any argument it should work like default constructor. Can anyone explain it? Seems I doing it wrong
What should I be calling the "BFactory" below. Its not really a Factory since there is no selection of a concrete class happening, and its not necessarily creating an object each time. Its kind of a Pool but the users do not return the Bs they get to the pool after they are done with them. It could be called a Cache but performance is not the primary intention. The intention is that everyone who is using the same BFactory will get the same B when they pass the same A which starts to sound kind of like a singleton-ish.
public class A
{
public int MyProperty { get; set; }
}
public class B
{
public B(A wrapped)
{
Wrapped = wrapped;
}
public A Wrapped { get; set; }
}
public class BFactory
{
private Dictionary<A,B> _created = new Dictionary<A,B>();
public B GetB(A a)
{
if (_created.ContainsKey(a) == false)
{
_created[a] = new B(a);
}
return _created[a];
}
}
here is a slightly more real example:
The value from MyModel is shown in several locations in the app by binding a TextBlock to the ValueString property of MyViewModel. The user can select to present the value as a percent or a decimal and it should be updated in all locations if it is updated in one.
public class MyModel
{
public int Value { get; set; }
}
public class MyViewModel
{
private readonly MyModel _model;
public MyViewModel(MyModel model)
{
_model = model;
}
public string ValueString
{
get { return string.Format(FormatString, _model.Value); }
}
public string FormatString { get; set; }
}
public class MyViewModelFactory
{
private readonly Dictionary<MyModel, MyViewModel> _created = new Dictionary<MyModel, MyViewModel>();
public MyViewModel GetViewModel(MyModel model)
{
if (_created.ContainsKey(model) == false)
{
_created[model] = new MyViewModel(model);
}
return _created[model];
}
}
[Serializable]
public class ModelResource:ISerializable
{
public Int64 Ore { get; private set; }
public Int64 Crystal { get; private set; }
public Int64 Hydrogen { get; private set; }
//needs to be ignored
public Int64 Total { get { return Ore + Hydrogen + Crystal; } }
public string ResourceType { get; private set; }
public Int64 HerculesNeeded { get { return Total / 25000; } }
public Int64 AtlasNeeded { get { return Total / 5000; } }
public bool IsPlanet { get { return ResourceType == "Planet"; } }
//causes serializer to stackoverflow
public ModelResource MakeChild {get{return new ModelResource(Ore/2,Crystal/2,Hydrogen/2);}}
public string ToJson()
{
var jss = new System.Web.Script.Serialization.JavaScriptSerializer(new SimpleTypeResolver());
return jss.Serialize(this); //throws recursion limit exceed exception
}
#region ISerializable Members
public void GetObjectData(SerializationInfo info, StreamingContext context)
{
info.AddValue("Ore", Ore);
info.AddValue("Crystal", Crystal);
info.AddValue("Hydrogen", Hydrogen);
info.AddValue("ResourceType", ResourceType);
}
private ModelResource(SerializationInfo si, StreamingContext context)
{
Ore = si.GetInt64("Ore");
Crystal = si.GetInt64("Crystal");
Hydrogen = si.GetInt64("Hydrogen");
ResourceType = si.GetString("ResourceType");
}
#endregion
}
Normally I would suggest telling it to ignore parent properties (which create cycles) - in this case by adding [ScriptIgnore] - but I can't see anything other than basic members - is this class by itself enough to cause the error?