I Have a problem with entity framework: When I call "Save Changes", the method throws an Exception: "The FieldName field is required". But when I inspect modified fields are present both fields and FK field.
I have no clues about what's happening.
Thanks in advance
EDIT:
The code is just:
context.SaveChanges();
and the entity have:
[Required]
[ForeignKey("FieldStateId")]
public virtual FieldState FieldState { get; set; }
public int FieldStateId { get; set; }
I follow the Steeve Greene comment and it works!
Try moving [Required] to FieldStateId, not the nav property.
Like almost always in development, I don't know how it worked before :)
Related
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.
I found out that, if i set a navigation property as required ( using the Required attribute ) and use lazy-loading proxies, when i load the parent entity and do nothing but try to save in the same context, an EntityValidationError occurs which is like "xxx field is required".
With hibernate in Java and NHibernate in .NET, it is possible to just fetch an entity without its navigation properties ( all lazy loaded ) , update it and save again. The framework realizes that nothing changed with the navigation references and do not throw any errors.
The example is below
[Table("Address")]
public class Address
{
[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int AddressId { get; set; }
[Required, StringLength(512)]
public virtual string AddressLine1 { get; set; }
}
[Table("User")]
public class User
{
[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int UserId { get; set; }
[Required]
public string Name {get; set;}
[Required]
public virtual Address Address {get; set;}
}
void LoadAndSaveUser() {
var user = Context.Users.First();
user.Name = "foo";
// if i comment out this line
// ( probably EF fetches the lazy loaded entiy )
// the code works. it is strange though because i don't access any property/method of the Address
// var dummy = user.Address
Context.SaveChanges();
}
When i try this without the "Required" attribute on the Address property, no error occurs. With the Required attribute, i get "Address field is required!". Since each user should have an address, i want the attribute to create a consistent model.
In some forums, i found posts suggesting to include the navigation property while loading the parent entity ( eager load in other words ) but it is not a feasible approach if we have too many navigation properties.
Am i doing something wrong or is there any other way to implement such funcionality ?
Define public int AddressId in your User class. It loads whenever a user is loaded. I think that will solve the problem.
Update:
Well, I have reproduced your problem. You have a couple of options to prevent this. But one thing's for sure. You have to remove the [Required] attribute from your Address property. This is the source of your problem (which is rational since you are telling EF "I want the Address object (not the foreign key but the navigation property) to be present. if it's null, throw an exception").
Also, define AddressId property of type int in your User class.
Notice that you can also define public virtual ICollection<User> Users { get; set; } in your Address entity.
You can tell EF about required attribute either by putting [Required] on AddressId, or by using fluent api:
in your user-mapping class:
this.HasRequired(t => t.Address)
.WithMany()
.HasForeignKey(d => d.AddressId);
This question already has answers here:
EF code first: Cannot insert explicit value for identity column in table '' when IDENTITY_INSERT is set to OFF
(3 answers)
Closed 4 years ago.
I'm trying out Entity Framework 4's Code First (EF CodeFirst 0.8) and am running into a problem with a simple model that has a 1 <--> 0..1 relationship, between Person and Profile. Here's how they're defined:
public class Person
{
public int PersonId { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public DateTime? DOB { get; set; }
public virtual Profile Profile { get; set; }
}
public class Profile
{
public int ProfileId { get; set; }
public int PersonId { get; set; }
public string DisplayName { get; set; }
public virtual Person Person { get; set; }
}
The DB context looks like this:
public class BodyDB : DbContext
{
public DbSet<Person> People { get; set; }
}
I didn't define a DbSet for Profile because I consider People to be its aggregate root. When I try to add a new Person - even one without a Profile with this code:
public Person Add(Person newPerson)
{
Person person = _bodyBookEntities.People.Add(newPerson);
_bodyBookEntities.SaveChanges();
return person;
}
I get the following error:
Cannot insert explicit value for identity column in table 'People' when IDENTITY_INSERT is set to OFF.
The newPerson object has a 0 for the PersonId property when I call People.Add(). The database tables are People and Profiles. PersonId is the PK of People and is an auto-increment Identity. ProfileId is the PK of Profiles and is an auto-incement Identity. PersonId is a non-null int column of Profiles.
What am I doing wrong? I think I'm adhering to all the EF Code First's convention over configuration rules.
I get the following error:
Cannot insert explicit value for identity column in table 'People' when IDENTITY_INSERT is set to OFF.
I think that the IDENTITY_INSERT is the Auto Increment functionality which is off.
So, check the field PersonId in the database to see if it is an identity.
Besides, maybe this will fix your problem too.
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public int PersonId { get; set; }
This will occur if you perform the following steps:
Create a non-identity PK field on a table.
Infer the Entity Model from that table.
Go back and set the PK identity to true.
The Entity Model and the database are out of sync. Refreshing the model will fix it. I had to do this just yesterday.
If you are using EF Code First, then, in addition to adding the [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)] annotation attribute to the model.cs file as others have suggested here, you also need to make the same effective change on the modelMap.cs files (the fluent mapping instructions):
Change from:
this.Property(t => t.id)
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);
to:
this.Property(t => t.id)
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
(I used the EF Power Tools to generate the entity models and the default mapping files, then later turned one Id column into a prmary key column and set it to IDENTITY in Sql Server, therefore, I had to update the attribute and the default mapping file.)
If you don't change it in both places, you'll still get the same error.
You situation reminds me situation I experience with EF Code First when PrimaryKey and ForeignKey are the same column.
There is no direct way to refresh the model, however the same effect can be achieved in 2 steps.
Comment out ProfileId in Profile class. Recompile and update database.
Uncomment Profile Id, add DatabaseGeneratedAttribute and update database again.
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.None), Key]
This way the generated ProfileId column becomes Key without Identity.
If you are using EF core and the fluent interface like me, I've found that the Scaffold-DbContext utility I've used to create the model from an existing db, generate a line for my column like that:
entity.Property(e => e.id).ValueGeneratedNever();
After I've changed the DB adding the IDENTITY attribute to my id, I had to change the row in:
entity.Property(e => e.id).ValueGeneratedOnAdd();
other than adding the [DatabaseGeneratedAttribute(DatabaseGeneratedOption.None), Key] decorator to the id field in my model class.
I'm not even sure if the latter is necessary. After resolved with the former fix, I didn't try to remove it.
I didn't have this problem until I added a composite key , so once I had 2 primary keys this occurred with EF 6.x.x
On my Key "Id" which has Identity Specification set to true I needed to add
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
Model properties now:
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
[Key, Column("Id", Order = 1)]
public int Id { get; set; }
[Key, Column("RanGuid", Order = 2)]
public string RanGuid { get; set; }
For the benefit of searchers: I got this error, but the above fixes did not work. It was due to an error on my part.
On my tables, I have a Guid Primary Key (non-clustered) and an int index.
The error was happening when trying to update the 'Post' with the 'Blog' info as a navigation property. See classes below:
public class Blog
{
public Guid BlogId { get; set; }
public int BlogIndex { get; set; }
// other stuff
}
public class Post
{
public Guid PostId { get; set; }
public int PostIndex { get; set; }
// other stuff
public Blog Blog { get; set; }
}
The issue was that when I was converting DTO's to models, the BlogId was being changed to a new Guid() (I made an error in the mapping). The resulting error was the same as detailed in this question.
To fix it, I needed to check the data was right when being inserted (it wasn't) and fix the incorrect change of data (in my case, the broken mapping).
Got this error in EF6, looked at the database and everything looked right with Identity Specification set to Yes. I then removed the different migrations and made one new migration from current models and then everything started working. Fastest solution since the application was not live yet and still in development.
Cannot insert explicit value for identity column in table
'Test' when IDENTITY_INSERT is set to OFF.
Here is the solution. Also see the attachment for more help.
Navigate to your EF model ".edmx" file >> Open it >> Now right click on the diagram and choose 'Update Model from Database'.
This will fix it because you made PK the Identity in your DB after you created your EF model.
help to recreate steps stated above
In my case it seems that EF doesn't like other type than INT identity field - mine was a BYTE (TINYINT on the SQL side).
Since I was able to update my project and change it to INT on the SQL, after re-running the Reverse Engineering Code First on VisualStudio, the error has immediately ceased to occur.
In my case it seems that EF doesn't like other type than INT identity field - mine was a BYTE (TINYINT on the SQL side).
I had this error too using PK of tinyint type. It's not that EF doesn't like it, it's seems that, unlike other cases, you have to specify that in your configuration like this:
this.Property(t => t.TableID).HasColumnName("TableID").HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
I have a model defined as
public class Department
{
[ScaffoldColumn(false)]
public object Id { get; set; }
[Required(ErrorMessage = "Department Name is required")]
[StringLength(25)]
[DisplayName("Department Name")]
public string Name { get; set; }
[DefaultValue(true)]
[DisplayName("Active?")]
public bool Active { get; set; }
}
i have added one record using the asp.net view. To retrieve the records i have created a simple index "DepartmentIndex" as
from dept in docs.Departments
select new {dept.Id,dept.Name}
To fetch the records I am using the following linq query
var depts = dbSession.Query<Department>("DepartmentIndex").OrderByDescending(x => x.Id);
Till here everything is fine. I can see the first record I have added on my view page. But, when I start adding more records i don't see the newly added ones. What have I missed?
RavenDB updates indexes in the background, so the results might be stale. See the documentation here for more info. In the client API you need to call the function WaitForNonStaleResults, to do this.
I was using build #133 i upgraded to #140 now, this doesn't seems to be a problem.
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.