I have tried DataAnnotation as described here, but it does not work for me.
I have a table with the following structure
Table - Category
id int (pk not null)
CategoryName varchar(100) (null)
I already created my edmx file and all.
I have created the Category.cs file also like below.
[MetadataType(typeof(CategoryMetaData))]
public partial class Category
{
}
public class CategoryMetaData
{
[Required(ErrorMessage = "Category Name is required.")]
public object CategoryName;
}
But my validations are not working.
Is there anything I've missed?
I have found that ObjectContext does not work with DataAnnotations. You have to switch to using DbContext, then it works. Download the EF 4.x DbContext T4 file and try it on your model. Not sure why this is true, was hoping an expert would chime in.
UPD
Solution here.
Before validating, you need to manually register the metadata class
==================
I suppose this problem is related to proxy classes, which EF generates for your entities. You can check this easily in runtime: just see GetType().FullName.
If attribute is marked as non-inheritable, it won't be applied in inherited class. And proxy classes derive from entity classes, so non-inheritable attributes are lost.
I'm trying to use DataAnnotations in WebForms project by checking attributes by hand. But neither
System.ComponentModel.DataAnnotations.Validator.TryValidateObject(entity, new ValidationContext(value, null, null), results, true);
nor
PropertyInfo[] properties = value.GetType()
.GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance);
var validationProperties = properties.Select(prop => new
{
Property = prop,
ValidationAttributes = Attribute.GetCustomAttributes(prop, typeof(ValidationAttribute), true)
}).Where(valProp => valProp.ValidationAttributes.Any());
doesn't work.
I've tried these code with simple class not related to EF, and all DataAnnotations attributes were found and checked correctly.
[MetadataType(typeof(TestValidObject_Metadata))]
public class TestValidObject
{
public string IdName { get; set; }
}
public class TestValidObject_Metadata
{
[Required, DisplayName("Id name")]
public object IdName { get; set; }
}
RequiredAttribute's definition is
[AttributeUsageAttribute(AttributeTargets.Property|AttributeTargets.Field|AttributeTargets.Parameter, AllowMultiple = false)]
public class RequiredAttribute : ValidationAttribute
and by default it becomes inheritable attribute. And I don't know why
Attribute.GetCustomAttributes(prop, typeof(ValidationAttribute), true)
// true specifies to also search the ancestors of element for custom attributes.
doesn't catch it.
Any ideas are welcome.
CategoryName in CateogryMetaData should be a property and has the same type as the original property. Try this:
public class CategoryMetaData
{
[Required(ErrorMessage = "Category Name is required.")]
public string CategoryName {get;set;}
}
Related
I have entities set up something like this:
public class MyThing
{
public int Id { get; set; }
public virtual MyOtherThing { get;set; }
}
public class MyOtherThing
{
public int Id { get; set; }
public virtual MyThing MyThing { get; set; }
}
My intention is that 'MyThing' can have one or none of MyOtherThing, and I also want a navigation link from MyOtherThing to it's parent.
I have configured the following EntityBaseConfiguration for the 'MyOtherThing' entity:
this.HasOptional(x => x.MyThing)
.WithOptionalPrincipal(x => x.MyOtherThing);
I can assign and modify MyOtherThing to MyThing no problem, but when I want to unassign 'MyOtherThing' from 'MyThing', how do I do this?
I tried the following:
myThing.MyOtherThing = null;
and then editing the entity by setting the EntityState.Modified state, but this didn't remove the association between the entities.
I tried adding the following to my MyThing entity, but this resulted in an EF 'Multiplicity is not valid' error when updating my database model:
public int? MyOtherThingId{ get; set; }
Thanks in advance!
I tried the following:
myThing.MyOtherThing = null;
If you want to remove an optional dependent entity (here: MyOtherThing) from a principal entity (here MyThing) by setting it to null, you have to pull the entity from the database with the dependent entity included, for example:
var mything = context.MyThings.Include(m => m.MyOtherThing)
.Single(t => t.Id == idValue);
(It's also OK when the belonging MyOtherThing is loaded into the context later, for example by lazy loading).
Without Include, myThing.MyOtherThing already is null and EF doesn't detect any change. Note that the statement myThing.MyOtherThing = null; doesn't execute lazy loading, which is a bit confusing because with collections the behavior is different.
By the way, the dependent entity can also be removed from the database directly, which is more efficient.
var ot = context.Set<MyOtherThing>().Find(idValue);
context.Set<MyOtherThing>().Remove(ot);
context.SaveChanges();
I have an entity that owns another entity
public class Entity1
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public virtual int ID { get; set; }
public string Property { get; set; }
public Entity2 Description { get; set; }
}
public class Entity2
{
public string Test { get; set; }
}
and I need to create an index on Entity1.Property and Entity2.Test. The configuration is like this
builder.OwnsOne(pt => pt.Description);
builder.HasIndex(p => new { p.Property, p.Description.Test }).IsUnique();
//builder.HasIndex("Property", "Description_Test").IsUnique();
I tried both of the above code but they do not work. The first says
The properties expression 'p => new <>f__AnonymousType3`7(Property = p.DeviceClassId,
Test = p.Description.Test)' is not valid. The expression should represent a property
access: 't => t.MyProperty'. When specifying multiple properties use an anonymous type:
't => new { t.MyProperty1, t.MyProperty2 }'.
Parameter name: propertyAccessExpression
and the second one says:
The property 'Description_test' cannot be added to the type 'Entity1' because there was no
property type specified and there is no corresponding CLR property or field. To add a
shadow state property the property type must be specified.
Can this be achieved without modifying the migration manually?
Apparently EF Core doesn't support this feature yet.
See this issue on GitHub:
https://github.com/aspnet/EntityFrameworkCore/issues/11336
There is also a workaround offered, which I have not tested myself.
A workaround that solved for me, was deleting in the migration's directory the autogenerated file DataContextModelSnapshot.cs and running again the migration it was regenerated, had some databases already referenced in the migration file that was just deleting and was done...
Might not be the most elegant solution, but it does work.
Just for reference, it happened with the EF Core 6.0 twice.
I haven't been able to find someone else with this issue specifically so here goes.
I have a simple model where one entity simply references another as a parent-child or one-to-many relationship defined like this:
public class Parent
{
public int ID { get; private set; }
public string Name { get; private set; }
}
public class Child
{
public int ID { get; private set; }
public string Name { get; private set; }
public virtual Parent Parent { get; private set; }
}
I am creating speicific mapping files for each, which work great for all the normal properties except for the related entity. It is always coming up null. No matter whether i have the virtual/private accessors on the property it will not load UNLESS i pull a copy of the parent separately from the context first. My mapping looks like this:
HasRequired(t => t.Parent).WithMany().Map(t => t.MapKey("ParentID")).WillCascadeOnDelete();
Is there anything I am doing wrong with this? I cannot for the life of me figure this out. Just so I cover all the bases, I am loading the entity like this:
Context.Set<Child>().FirstOrDefault(x => x.ID == 1);
And lastly here are some constraints I have:
I cannot have the foreign keys in my model as properties.
I cannot have a collection of children from the parent.
I finally figured it out. After much trial and error I noticed that having a parameterless constructor marked as internal, EF cannot create its dynamic proxy class of your type and therefore disables all lazy loading. I have two contructors, one for EF to hydrate objects, and another with parameters requires for callers to create my entity. Once I changed the signature to protected internal it started working. So I changed this:
internal Child() {}
to
protected internal Child() {}
May be you hasn't enable lazy loading .Try this,
Context.Set<Child>().FirstOrDefault(x => x.ID == 1).Include(c=>c.Parent);
A little new to EF, so please bear with me if the answer to this is obvious. I'm doing a tutorial that uses EF, and two DbSets are defined like this:
public DbSet<BrokerageAccount> BrokerageAccounts { get; set; }
public DbSet<Customer> Customers { get; set; }
The customer class looks like this-- it's a POCO (some code cut for brevity):
public class Customer
{
public Customer()
{
BrokerageAccounts = new HashSet<BrokerageAccount>();
}
// Primitive properties
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
// Navigation properties
public ICollection<BrokerageAccount> BrokerageAccounts { get; set; }
}
}
The BrokerageAccount class is a POCO as well, very similar in design to Customer.
So far so good. The code I have a question about is below. There is an association made in the main program between Customer and BrokerageAccount that I don't follow. The code reads like this:
public Customer GetCustomer(string custId)
{
using (var context = DataContext)
{
return context.Customers
.Include("BrokerageAccounts").SingleOrDefault(c => c.CustomerCode == custId);
}
}
I can't figure out how the association/join is made between Customer and BrokerageAccount. I don't see any config or other files in my VS 2010 project that tells what associates the two DbSets, what foreign key column to use, etc.
Perhaps I'm missing something obvious or a mapping file of some sort, but just because Customer has an ICollection of BrokerageAccount along with a comment above that says "Navigation Properties", doesn't make it so. In EF, how are those associations established?
The normal way of setting up the navigation properties is to use the ModelBuilder, This gives you a fluent api to set up the associations, take a look at this for some in depth stuff about how you go about this.
http://xhalent.wordpress.com/2011/01/21/configuring-entity-framework-4-codefirst/
Entity framework will guess at what you meant if you dont set up the nav properties manually, in the above case it will probably set up your nav properties as expected as you only have a single 1-* relationship between customer and BrokerageAccount which appears to be named sensibly.
There is also an attribute method that you can use to set up the navigation properties.
VS 2010 Beta 2, .NET 4.
In my ASP.NET MVC 2 application, when I submit a form to an action method that accepts an object created by the entity framework, I get the following error:
Exception Details: System.Data.ConstraintException: This property cannot be set to a
null value.
Source Error:
Line 4500: OnTextChanging(value);
Line 4501: ReportPropertyChanging("Text");
Line 4502: _Text = StructuralObject.SetValidValue(value, false);
Line 4503: ReportPropertyChanged("Text");
Line 4504: OnTextChanged();
The property is called "Text" and is of type "text NOT NULL" in MS SQL 2008.
My action will check if the value is nullorempty, if it is, a model error will be added, but I get the error as soon as I submit the form.
Are you binding directly to the entity? Sure looks like it. So you have two choices:
Write a custom model binder which translates null -> empty string.
Bind to an edit model which allows nulls instead, and then change this to empty string when you copy the values to the entity in the action.
I'd choose #2, personally. I think you should always use view/edit models, and this is a great example of why.
I was having the same problem. I looked around and found a work around here. It describes the problem as being caused by the EF validation taking place before the Required field validation. It also shows how we can work around this problem by using a [DisplayFormat] Tag. Hope this will help you.
Here's the link to the question and the workaround:
Server-side validation of a REQUIRED String Property in MVC2 Entity Framework 4 does not work
Is this an issue with the MVC2 and Entity Framework 4 or is this by design? It appears that validation of EF properties works fine for datetime non-nullable (required) fields and data type validation of numeric versus string fields is working without having to use ViewModels.
I recreated the issue using with a simple FOOBAR table using a single, non-nullable varchar(50) column called barName in slq 2008. I generated the EF model from that database and quickly added a controller and a CREATE view for the FOOBAR entity. If I try to POST to the CREATE action without entering in a value for the property barName, VS steps into an exception within the designer.cs file of the model (just like the one above). When, I try to step past the exception, the validation message shows up on the form and the field is highlighted in pink.
It seems like something is not firing in the correct sequence. Because the exception occurs before VS steps into the HTTPPOST CREATE method.
I found the code from the ASP.Net MvcMusicStore sample helpful. http://mvcmusicstore.codeplex.com/releases/view/44445#DownloadId=119336
It appears that binding to the ViewModel fixes the issue.
namespace MvcMusicStore.ViewModels
{
public class StoreManagerViewModel
{
public Album Album { get; set; }
public List<Artist> Artists { get; set; }
public List<Genre> Genres { get; set; }
}
}
........
namespace MvcMusicStore.Models
{
[MetadataType(typeof(AlbumMetaData))]
public partial class Album
{
// Validation rules for the Album class
[Bind(Exclude = "AlbumId")]
public class AlbumMetaData
{
[ScaffoldColumn(false)]
public object AlbumId { get; set; }
[DisplayName("Genre")]
public object GenreId { get; set; }
[DisplayName("Artist")]
public object ArtistId { get; set; }
[Required(ErrorMessage = "An Album Title is required")]
[StringLength(160)]
public object Title { get; set; }
[DisplayName("Album Art URL")]
[StringLength(1024)]
public object AlbumArtUrl { get; set; }
[Required(ErrorMessage = "Price is required")]
[Range(0.01, 100.00, ErrorMessage="Price must be between 0.01 and 100.00")]
public object Price { get; set; }
}
}
}
Ashish Shakya's answer helped me. I added this attribute to the property and now it works.
[DisplayFormat(ConvertEmptyStringToNull = false, NullDisplayText="")]
So it looks like this:
[EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)]
[DataMemberAttribute()]
[DisplayFormat(ConvertEmptyStringToNull = false, NullDisplayText="")]
public global::System.String MyProperty
{
get
{
return _MyProperty;
}
set
{
OnMyPropertyChanging(value);
ReportPropertyChanging("MyProperty");
_MyProperty = StructuralObject.SetValidValue(value, false);
ReportPropertyChanged("MyProperty");
OnMyPropertyChanged();
}
}
Import the namespace:
using System.ComponentModel.DataAnnotations;
And add the attribute property [Required]
[Required]
public global::System.String MyProperty
{
get
{
return _MyProperty;
}
set
{
OnMyPropertyChanging(value);
ReportPropertyChanging("MyProperty");
_MyProperty = StructuralObject.SetValidValue(value, false);
ReportPropertyChanged("MyProperty");
OnMyPropertyChanged();
}
}
Thus ModelState.IsValid equals false, showing error message in the validation and will not fail on the server with Null.
I had the same problem and fixed it by making false to true like this:
Line 4502:
_Text = StructuralObject.SetValidValue(value, false);
I just had the same problem myself, and came here to find the solution. However, the answer can be enhanced.
Svavar's and HackITMngr were on the right track, however combining both gives the best outcome. You don't want to go decorating the generated classes, as you risk losing your custom changes upon modifications to the EF model.
[MetadataType(typeof(MyTableMetaData))]
public partial class MyTable
{
// Validation rules for the Album class
public class MyTableMetaData
{
[DisplayFormat(ConvertEmptyStringToNull = false, NullDisplayText="")]
public string MyTextProperty { get; set; }
}
}
To settle any arguments between the two. I'd say Svavar's was the direct answer, HackITMngr was the enhancement.
Works great for me!
I set StoreGeneratedPattern property as Computed for each field and it solved the problem for me.