Validation error with foreign key - entity-framework-5

When I have this simple model:
public class User
{
// Primary key
[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public Guid UserId { get; set; }
[Required]
public Int32 FailedPasswordAttemptCount { get; set; }
[Required]
public Language Language { get; set; }
}
public class Language
{
[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public Guid LanguageId { get; set; }
[MaxLength(30)]
public String LocaleName { get; set; }
}
And I do this code:
var user = context.Users.Single(u => u.UserId == userId);
user.FailedPasswordAttemptCount++;
context.SaveChanges();
It will throw an DbEntityValidationException expception The Language field is required..
Technically this is true because the property is marked as required and because the Language property is null when fetched from the database (no lazy or eager loading).
But how do I change this behaviour?
I don't want to disable validation completely
I don't want to lazy / eager load the field
I don't want to remove the Required tag from the model
What other options are out there?


You can prevent this by adding the primitive FK field (probably LanguageId) to your User class. This is not uncommon in entity framework. There are more occasions where getting or setting the primitive property saves work or unnecessary (lazy) loading.

Related

Data annotation in Servicestack References vs ForeignKey

Well, in ServiceStack
where can I read up on the merits and differences of
[References(typeof(ABC))] and
[ForeignKey(typeof(XYZ) ]
What are they used for ? (I know, rather naively put but I have a hard time finding the basic description)

The docs for both are referenced throughout ServiceStack.OrmLite project page.
Use either for simple Foreign Keys
Essentially they're both equivalent to define simple Foreign Keys which you can use either for:
[References(typeof(ForeignKeyTable1))]
public int SimpleForeignKey { get; set; }
[ForeignKey(typeof(ForeignKeyTable1))]
public int SimpleForeignKey { get; set; }
The [References] attribute is also used by other data persistence libraries like PocoDynamo for DynamoDb where it would be preferred when wanting to re-use your existing data models else where, it's also useful as a benign "marker" attribute on different models when you want to include a navigable reference to an associated type for the property.
Fine-grained Foreign Key options
The [ForeignKey] is specific to OrmLite and includes additional fine-grained options for defining foreign key relationships specific to RDBMS's like different cascading options, e.g:
public class TableWithAllCascadeOptions
{
[AutoIncrement] public int Id { get; set; }
[ForeignKey(typeof(ForeignKeyTable1))]
public int SimpleForeignKey { get; set; }
[ForeignKey(typeof(ForeignKeyTable2), OnDelete = "CASCADE", OnUpdate = "CASCADE")]
public int? CascadeOnUpdateOrDelete { get; set; }
[ForeignKey(typeof(ForeignKeyTable3), OnDelete = "NO ACTION")]
public int? NoActionOnCascade { get; set; }
[Default(typeof(int), "17")]
[ForeignKey(typeof(ForeignKeyTable4), OnDelete = "SET DEFAULT")]
public int SetToDefaultValueOnDelete { get; set; }
[ForeignKey(typeof(ForeignKeyTable5), OnDelete = "SET NULL")]
public int? SetToNullOnDelete { get; set; }
}

ServiceStack - [Reference] or [Ignore]?

We have a DTO - Employee - with many (> 20) related DTOs and DTO collections. For "size of returned JSON" reasons, we have marked those relationships as [Ignore]. It is then up to the client to populate any related DTOs that they would like using other REST calls.
We have tried a couple of things to satisfy clients' desire to have some related Employee info but not all:
We created a new DTO - EmployeeLite - which has the most-requested fields defined with "RelatedTableNameRelatedFieldName" approach and used the QueryBase overload and that has worked well.
We've also tried adding a property to a request DTO - "References" - which is a comma-separated list of related DTOs that the client would like populated. We then iterate the response and populate each Employee with the related DTO or List. The concern there is performance when iterating a large List.
We're wondering if there a suggested approach to what we're trying to do?
Thanks for any suggestions you may have.
UPDATE:
Here is a portion of our request DTO:
[Route("/employees", "GET")]
public class FindEmployeesRequest : QueryDb<Employee> {
public int? ID { get; set; }
public int[] IDs { get; set; }
public string UserID { get; set; }
public string LastNameStartsWith { get; set; }
public DateTime[] DateOfBirthBetween { get; set; }
public DateTime[] HireDateBetween { get; set; }
public bool? IsActive { get; set; }
}
There is no code for the service (automagical with QueryDb), so I added some to try the "merge" approach:
public object Get(FindEmployeesRequest request) {
var query = AutoQuery.CreateQuery(request, Request.GetRequestParams());
QueryResponse<Employee> response = AutoQuery.Execute(request, query);
if (response.Total > 0) {
List<Clerkship> clerkships = Db.Select<Clerkship>();
response.Results.Merge(clerkships);
}
return response;
}
This fails with Could not find Child Reference for 'Clerkship' on Parent 'Employee'
because in Employee we have:
[Ignore]
public List<Clerkship> Clerkships { get; set; }
which we did because we don't want "Clerkships" with every request. If I change [Ignore] to [Reference] I don't need the code above in the service - the List comes automatically. So it seems that .Merge only works with [Reference] which we don't want to do.
I'm not sure how I would use the "Custom Load References" approach in an AutoQuery service. And, AFAIKT, the "Custom Fields" approach can't be use for related DTOs, only for fields in the base table.
UPDATE 2:
The LoadSelect with include[] is working well for us. We are now trying to cover the case where ?fields= is used in the query string but the client does not request the ID field of the related DTO:
public partial class Employee {
[PrimaryKey]
[AutoIncrement]
public int ID { get; set; }
.
.
.
[References(typeof(Department))]
public int DepartmentID { get; set; }
.
.
.
public class Department {
[PrimaryKey]
public int ID { get; set; }
public string Name { get; set; }
.
.
.
}
So, for the request
/employees?fields=id,departmentid
we will get the Department in the response. But for the request
/employees?fields=id
we won't get the Department in the response.
We're trying to "quietly fix" this for the requester by modifying the query.SelectExpression and adding , "Employee"."DepartmentID" to the SELECT before doing the Db.LoadSelect. Debugging shows that query.SelectExpression is being modified, but according to SQL Profiler, "Employee"."DepartmentID" is not being selected.
Is there something else we should be doing to get "Employee"."DepartmentID" added to the SELECT?
Thanks.
UPDATE 3:
The Employee table has three 1:1 relationships - EmployeeType, Department and Title:
public partial class Employee {
[PrimaryKey]
[AutoIncrement]
public int ID { get; set; }
[References(typeof(EmployeeType))]
public int EmployeeTypeID { get; set; }
[References(typeof(Department))]
public int DepartmentID { get; set; }
[References(typeof(Title))]
public int TitleID { get; set; }
.
.
.
}
public class EmployeeType {
[PrimaryKey]
public int ID { get; set; }
public string Name { get; set; }
}
public class Department {
[PrimaryKey]
public int ID { get; set; }
public string Name { get; set; }
[Reference]
public List<Title> Titles { get; set; }
}
public class Title {
[PrimaryKey]
public int ID { get; set; }
[References(typeof(Department))]
public int DepartmentID { get; set; }
public string Name { get; set; }
}
The latest update to 4.0.55 allows this:
/employees?fields=employeetype,department,title
I get back all the Employee table fields plus the three related DTOs - with one strange thing - the Employee's ID field is populated with the Employee's TitleID values (I think we saw this before?).
This request fixes that anomaly:
/employees?fields=id,employeetypeid,employeetype,departmentid,department,titleid,title
but I lose all of the other Employee fields.
This sounds like a "have your cake and eat it too" request, but is there a way that I can get all of the Employee fields and selective related DTOs? Something like:
/employees?fields=*,employeetype,department,title

AutoQuery Customizable Fields
Not sure if this is Relevant but AutoQuery has built-in support for Customizing which fields to return with the ?fields=Field1,Field2 option.
Merge disconnected POCO Results
As you've not provided any source code it's not clear what you're trying to achieve or where the inefficiency with the existing solution lies, but you don't want to be doing any N+1 SELECT queries. If you are, have a look at how you can merge disconnected POCO results together which will let you merge results from separate queries based on the relationships defined using OrmLite references, e.g the example below uses 2 distinct queries to join Customers with their orders:
//Select Customers who've had orders with Quantities of 10 or more
List<Customer> customers = db.Select<Customer>(q =>
q.Join<Order>()
.Where<Order>(o => o.Qty >= 10)
.SelectDistinct());
//Select Orders with Quantities of 10 or more
List<Order> orders = db.Select<Order>(o => o.Qty >= 10);
customers.Merge(orders); // Merge disconnected Orders with their related Customers
Custom Load References
You can selectively control which references OrmLite should load by specifying them when you call OrmLite's Load* API's, e.g:
var customerWithAddress = db.LoadSingleById<Customer>(customer.Id,
include: new[] { "PrimaryAddress" });
Using Custom Load References in AutoQuery
You can customize an AutoQuery Request to not return any references by using Db.Select instead of Db.LoadSelect in your custom AutoQuery implementation, e.g:
public object Get(FindEmployeesRequest request)
{
var q = AutoQuery.CreateQuery(request, Request);
var response = new QueryResponse<Employee>
{
Offset = q.Offset.GetValueOrDefault(0),
Results = Db.Select(q),
Total = (int)Db.Count(q),
};
return response;
}
Likewise if you only want to selectively load 1 or more references you can change LoadSelect to pass in an include: array with only the reference fields you want included, e.g:
public object Get(FindEmployeesRequest request)
{
var q = AutoQuery.CreateQuery(request, Request);
var response = new QueryResponse<Employee>
{
Offset = q.Offset.GetValueOrDefault(0),
Results = Db.LoadSelect(q, include:new []{ "Clerkships" }),
Total = (int)Db.Count(q),
};
return response;
}

How to design DTO classes for nested domain objects?

I am new to using DTOs.
I have two domain classes:
Category
Product
as follows
public class Category
{
// Properties
public int Id { get; set; }
public string Name { get; set; }
// Navigation properties
public virtual Category ParentCategory { get; set; }
// Foreign key
public int? ParentCategoryId { get; set; }
// Collections
public virtual ICollection<Product> Products { get; set; }
public virtual ICollection<Category> Subcategories { get; set; }
}
public class Product
{
// Properties
public int Id { get; set; }
public string Name { get; set; }
// Navigation property
public virtual Category Category { get; set; }
// Foreign key
public int CategoryId { get; set; }
}
I want to use Automapper.
I am not sure how to design DTOs for the above aggregate (graph).
Should CategoryDTO have a collection of type ProductDTO or a collection of type Product?
Should ProductDTO have a CategoryDTO as navigation property or a Category or just an Id to the Category?
Can anyone suggest the code for DTOs?
How should this structure be flattened (if it should) and mapped to domain classes?
Many thanks in advance.

I design my DTOs to be only the data used for a specific controller action for MVC. Typically this means if I have a CategoryController, then I have a CategoryIndexModel, CategoryDetailsModel, CategoryEditModel etc etc. Only include the information you want on that screen. I flatten as much as I can, I don't create child DTOs unless I have a Partial or collection.

Breeze doesn't expand TPH entities correctly

Breeze doesn't expand TPH entities correctly.
When using expand in breeze if you are using TPH expand will only work for the first entity, the others properties will be null. If I change the entity not to use inheritances it works fine. I've also tested returning each entity separately in an expand query that also worked fine.
//client side code
var getResidentById = function (id, obs) {
var query = EntityQuery.from('Residents')
.where('id', '==', id)
.expand('user, currentUnit, leases, leases.unit, leases.leaseStatus');
return manager.executeQuery(query).then(function (data) {
if (obs) {
obs(data.results[0])
}
}, queryFailed);
};
//Controler Endpoint
[HttpGet]
public IQueryable<Resident>
{
return _context.Context.UserDetails.OfType<Resident>();
}
//Model
public class UserDetail : EntityBase<int>, IArchivable, IHasPhoto, IDeactivatableEntity, IUpdatable
{
public bool IsArchived { get; set; }
public int LastUpdatedById { get; set; }
public UserProfile LastUpdatedBy { get; set; }
public DateTimeOffset LastUpdatedDate { get; set; }
public string PhotoUri { get; set; }
public bool IsInactive { get; set; }
}
public abstract class UserBelongsToApartmentComplex : UserDetail, IBelongsToApartmentComplex
{
public int ApartmentComplexId { get; set; }
public virtual ApartmentComplex ApartmentComplex { get; set; }
public virtual bool IsInSameComplexAs(IRelatedToApartmentComplex otherEntity)
{
return ApartmentComplexId == otherEntity.ApartmentComplexId;
}
}
public class Staff : UserBelongsToApartmentComplex
{
public string Title { get; set; }
}
public class Admin : UserDetail
{
public string AccessLevel { get; set; }
}
public class Resident : UserBelongsToApartmentComplex
{
public string Pets { get; set; }
public bool HasInsurance { get; set; }
public virtual IList<Lease> Leases { get; set; }
public int? CurrentUnitId { get; set; }
public virtual Unit CurrentUnit { get; set; }
public Resident()
{
Leases = new List<Lease>();
}
}
//response data from sever from endpoint public IQueryable Residents()
[{"$id":"1","$type":"RadiusBlue.Core.Models.Resident, RadiusBlue.Core","Pets":"Sadie, a westie","HasInsurance":false,"Leases":[{"$id":"2","$type":"RadiusBlue.Core.Models.Lease, RadiusBlue.Core","Start":"2012-05-23T00:00:00.000","End":"2013-05-23T00:00:00.000","UnitId":2,"Unit":{"$id":"3","$type":"RadiusBlue.Core.Models.Unit, RadiusBlue.Core","Building":"B","Floor":2,"ModelName":"Tera","RentAmount":2500.00,"NumberOfBeds":1,"NumberOfBaths":3,"UnitName":"102A","IsInactive":true,"Inhabitants":[],"ApartmentComplexId":1,"ApartmentComplex":{"$id":"4","$type":"RadiusBlue.Core.Models.ApartmentComplex, RadiusBlue.Core","Name":"The Stratford","StreetAddress":"100 S Park Ave","City":"Winter Park","StateId":10,"ZipCode":"32792","PropertyManagementCompanyId":1,"IsInactive":false,"TimeZoneId":"Eastern Standard Time","TimeZone":{"$id":"5","$type":"System.TimeZoneInfo, mscorlib","Id":"Eastern Standard Time","DisplayName":"(UTC-05:00) Eastern Time (US & Canada)","StandardName":"Eastern Standard Time","DaylightName":"Eastern Daylight Time","BaseUtcOffset":"-PT5H","AdjustmentRules":[{"$id":"6","$type":"System.TimeZoneInfo+AdjustmentRule, mscorlib","DateStart":"0001-01-01T00:00:00.000","DateEnd":"2006-12-31T00:00:00.000","DaylightDelta":"PT1H","DaylightTransitionStart":{"$id":"7","$type":"System.TimeZoneInfo+TransitionTime, mscorlib","TimeOfDay":"0001-01-01T02:00:00.000","Month":4,"Week":1,"Day":1,"DayOfWeek":"Sunday","IsFixedDateRule":false},"DaylightTransitionEnd":{"$id":"8","$type":"System.TimeZoneInfo+TransitionTime, mscorlib","TimeOfDay":"0001-01-01T02:00:00.000","Month":10,"Week":5,"Day":1,"DayOfWeek":"Sunday","IsFixedDateRule":false}},{"$id":"9","$type":"System.TimeZoneInfo+AdjustmentRule, mscorlib","DateStart":"2007-01-01T00:00:00.000","DateEnd":"9999-12-31T00:00:00.000","DaylightDelta":"PT1H","DaylightTransitionStart":{"$id":"10","$type":"System.TimeZoneInfo+TransitionTime, mscorlib","TimeOfDay":"0001-01-01T02:00:00.000","Month":3,"Week":2,"Day":1,"DayOfWeek":"Sunday","IsFixedDateRule":false},"DaylightTransitionEnd":{"$id":"11","$type":"System.TimeZoneInfo+TransitionTime, mscorlib","TimeOfDay":"0001-01-01T02:00:00.000","Month":11,"Week":1,"Day":1,"DayOfWeek":"Sunday","IsFixedDateRule":false}}],"SupportsDaylightSavingTime":true},"Users":[{"$ref":"1"}],"Groups":[],"IsArchived":false,"ApartmentComplexId":1,"Id":1},"Id":2},"ResidentId":3,"Resident":{"$ref":"1"},"LeaseStatusId":4,"LeaseStatus":{"$id":"12","$type":"RadiusBlue.Core.Models.LeaseStatus, RadiusBlue.Core","Description":"Lost","Id":4},"Id":1},{"$id":"13","$type":"RadiusBlue.Core.Models.Lease, RadiusBlue.Core","Start":"2013-05-24T00:00:00.000","End":"2014-05-24T00:00:00.000","UnitId":1,"Unit":{"$id":"14","$type":"RadiusBlue.Core.Models.Unit, RadiusBlue.Core","Building":"A","Floor":2,"ModelName":"Aqua","RentAmount":2000.00,"NumberOfBeds":2,"NumberOfBaths":1,"UnitName":"101A","IsInactive":true,"Inhabitants":[{"$ref":"1"}],"ApartmentComplexId":1,"ApartmentComplex":{"$ref":"4"},"Id":1},"ResidentId":3,"Resident":{"$ref":"1"},"LeaseStatusId":1,"LeaseStatus":{"$id":"15","$type":"RadiusBlue.Core.Models.LeaseStatus, RadiusBlue.Core","Description":"Active","Id":1},"Id":2}],"CurrentUnitId":1,"CurrentUnit":{"$ref":"14"},"ApartmentComplexId":1,"ApartmentComplex":{"$ref":"4"},"Id":3,"User":{"$id":"16","$type":"RadiusBlue.Core.Models.UserProfile, RadiusBlue.Core","UserName":"vjiawon#gmail.com","FirstName":"Vishal","LastName":"Jiawon","Age":27,"PhoneNumber":"123 456 7890","IsInactive":false,"UserDetail":{"$ref":"1"},"GroupMembers":[],"MaintenanceRequests":[],"Id":3},"IsArchived":false,"LastUpdatedById":1,"LastUpdatedDate":"0001-01-01T00:00:00.000+00:00","IsInactive":false,"CreatedById":1,"CreatedDate":"0001-01-01T00:00:00.000+00:00"}]

I do not doubt that there is a bug in BreezeJS somewhere.
I can report that, at least as of v.1.3.4, Breeze can expand multiple navigation properties of a TPH class ... and not just on the first entity returned.
I just modified the "can navigate to AccountType eagerly loaded with expand" test in inheritanceTests.js in DocCode so that (a) it also expands the Status navigation and (b) the tests are performed on the 3rd entity returned rather than the 1st.
The query is something like this:
var em = newEm(); // clean, empty EntityManager
return EntityQuery.from('bankRootTPHs').take(3)
.expand('AccountType, Status'))
.using(em).execute().then(success).fail(handleFail);
...
function success(data) {
var entity = data.results[data.results.length-1]; // get the last one (the 3rd)
var type = data.query.entityType.shortName;
if (!entity) {
ok(false, "a query failed to return a single " + type);
}
// more tests
// I just set a breakpoint and inspected
// entity.accountType() and entity.status()
// Both returned the expected related entities
}
I see that both the related AccountType and the related Status are available from the entity.
So something else is wrong.
Questions about your Example
First I am compelled to observe that you have a lot of expands. I count 5 related entities. That can hurt performance. I know we're not talking about that but I'm calling it out.
Second, the super class UserDetail is concrete but the intermediate derived class UserBelongsToApartmentComplex is abstract. You have inheritance class hierarchies that go concrete/abstract/concrete. The queried type, Residents is one such class. And a class at every level maps to the "UserDetail" table, yes?
I'm pretty sure we didn't test for that scenario ... which is pretty uncommon. I wasn't even sure that worked! For now I have to take your word for it that EF allows such a construct.
It would seem that BreezeJS is confused about it. We'll take a look.

servicestack ormlite and foreign keys to same table

I have a table of links, and some links will be child links, referencing the parent links ID
however i can not get my head around servicestack ormlite and populating a property of children, will all the child links when getting a list of all links.
Here is my model:
public partial class Navigation
{
[Alias("Id"), AutoIncrement]
public int Id { get; set; }
[Alias("ParentId")]
[Display( Name = "ParentId")]
[References(typeof(Navigation))]
public int? ParentId { get; set; }
[Alias("LinkText")]
[StringLength(50, ErrorMessage = " Must be no more than 50 characters long!")]
[Display( Name = "LinkText")]
public string LinkText { get; set; }
[Alias("Action")]
[StringLength(50, ErrorMessage = " Must be no more than 50 characters long!")]
[Display( Name = "Action")]
public string Action { get; set; }
[Alias("Controller")]
[StringLength(50, ErrorMessage = " Must be no more than 50 characters long!")]
[Display( Name = "Controller")]
public string Controller { get; set; }
[Alias("Area")]
[StringLength(50, ErrorMessage = " Must be no more than 50 characters long!")]
[Display( Name = "Area")]
public string Area { get; set; }
[Alias("Visible")]
[Display( Name = "Visible"),Required(ErrorMessage = " is required" )]
public bool Visible { get; set; }
[Alias("Sequence")]
[Display( Name = "Sequence")]
public int? Sequence { get; set; }
[ForeignKey(typeof(Navigation))]
public virtual ICollection<Navigation> Children { get; set; }
}
any ideas ?

You can do that using inheritance. The parent class will contain a reference to the child class. I had to use it to get which user have created each user. Here is a sample:
public class UserCommon
{
[References(typeof(User))] // Self reference workaround for User ;)
public Guid CreatedBy { get; set; }
}
public class User : UserCommon
{
public Guid Uid { get; set; }
public String Username { get; set; }
public String Password { get; set; }
}
Something you need to pay attention to is to include the Id in the child class not the parent. The table that will be generated is as follow. The foreign key is a self reference
Getting the list of children should be as easy as a simple LINQ query that will fetch all children for a certain parent Guid. CreatedBy is also a property of User becuase of inheritance.
db.Select<User>(q => q.CreatedBy == '734FD814-024D-4795-AFD0-34FECF89A13A');
// Just a sample Guid, you should be able to select
// the Guid you need and insert it here.

Tables in OrmLite are strictly a 1:1 mapping with the underlying db tables.
This means all complex type properties are blobbed into a db text field with the property name, they're never used to auto-map to child relations as you're expecting to do here.
Here's an early answer that shows how you could map many to many relations with OrmLite.

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